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Endocrinology Vol. 139, No. 3 1115-1124
Copyright © 1998 by The Endocrine Society

ARTICLES

Glucose Homeostasis in the Nonobese Diabetic Mouse at the Prediabetic Stage1

Abdelaziz Amrani, Sylvie Durant, Mark Throsby, Josiane Coulaud, Mireille Dardenne and Françoise Homo-Delarche

Centre National de la Recherche Scientifique Unité de Recherches Associée 1461 - Université Paris V, Hôpital Necker, 75015 Paris, France

Address all correspondence and requests for reprints to: Françoise Homo-Delarche, Centre National de la Recherche Scientifique Unité de Recherches Associeé 1461, Hôpital Necker, 161, rue de Sèvres, 75743 Paris Cedex 15, France. E-mail: dardenne{at}infobiogen.fr


   Abstract
Top
 Abstract
Introduction
 Materials and Methods
 Results
 Discussion
 References
 
Because few data were available on glucose homeostasis at the early prediabetic stage in the nonobese diabetic (NOD) mouse, we investigated glycemia, insulinemia, and pancreatic insulin content under basal conditions in both sexes of 4-, 6-, and 8-week-old fed NOD mice, compared with sex- and age-matched fed C57BL/6 mice. We also investigated glucose tolerance in both sexes of fasting 8-week-old NOD and C57BL/6 mice. The main results obtained under basal fed conditions, when comparing both strains, were lower glycemia and higher insulinemia in NOD females at all ages investigated and in NOD males (particularly at 6 weeks of age). Glucose tolerance tests showed that: 1) the blood glucose response to 1 g/kg ip glucose was less sustained in both sexes of 8-week-old NOD mice than in their control counterparts; 2) the blood insulin response to glucose (1 g/kg ip) appeared earlier in both sexes of NOD mice than in sex-matched C57BL/6 mice; 3) an unusual sexual dimorphism existed in NOD mice, compared with controls, with females secreting, in response to glucose, twice as much insulin as males; 4) dose-response studies (1–6 g/kg glucose) confirmed the lower increase in blood glucose levels in both sexes of NOD mice and their unusual sexual dimorphism in insulin secretion; and 5) glucose tolerance tests in 4- to 8-week-old NOD mice showed that although the sexual dimorphism in insulin secretion was not observed in 4-week-old mice, it was particularly striking at 6 weeks of age. Taken together, these results suggest that ß-cell hyperactivity exists in the NOD mouse at the early prediabetic stage, especially in NOD females.


   Introduction
Top
 Abstract
 Introduction
Materials and Methods
 Results
 Discussion
 References
 
INSULIN-DEPENDENT diabetes mellitus (IDDM), or type 1 diabetes, has a long prodromic phase in both humans (in whom the detection of autoantibodies precedes diabetes onset by years) and spontaneous models of the disease, such as the nonobese diabetic (NOD) mouse (in which insulitis precedes hyperglycemia by weeks or months) (1, 2). In first-degree relatives of IDDM patients, with regard to glucose homeostasis, data vary from normal to subnormal or, even more surprisingly, to excessive insulin and C-peptide secretion in response to glucose and/or arginine (1, 2, 3, 4, 5, 6, 7, 8). In line with the possible existence of hyperactive ß-cells at the prediabetic stage in humans, the following have been observed: 1) increased levels of insulin and proinsulin under basal fasting conditions in nondiabetic identical twins of IDDM patients (5, 6); and 2) increased levels of proinsulin under basal conditions and after glucose stimulation in first-degree relatives or newly diagnosed patients (3, 9, 10, 11, 12, 13, 14). In spontaneous experimental models of IDDM, most data dealing with glucose homeostasis at the prediabetic stage demonstrated a lower insulin response to glucose in both BB rats (15, 16, 17, 18, 19, 20, 21) and NOD mice (22, 23, 24, 25, 26). However, in the BB rat in particular, the existence of hyperactive ß-cells at the prediabetic stage can be suggested on the basis of the following findings: 1) hyperinsulinemia in some rats before the onset of diabetes (19); and 2) enhanced in vitro ß-cell sensitivity to glucose in inflamed islets, but not normal islets, from nondiabetic BB rats (27).

The conflicting data cited above could reflect the fact that the observations may involve different steps in the progression of the prediabetic stage. For example, in our investigation on stress effects in 2-month-old prediabetic NOD mice, we observed that, 2 h after saline injection, plasma insulin concentrations were significantly higher in NOD than in age-matched C57BL/6 females (28). Moreover, we also showed an unexpected recovery of insulin secretion during immobilization stress, only in 2-month-old NOD females, compared with age-matched C57BL/6 females and NOD and C57BL/6 males, in which insulin reduction was, as normally described, sustained throughout the stress period (29). These findings indicated that insulin production was far from being impaired at the prediabetic stage in NOD females, despite the progression of insulitis, and these results even suggest the existence of some ß-cell hyperactivity (30). We therefore examined various parameters of glucose homeostasis (glycemia, insulinemia, and pancreatic insulin content) under basal conditions in both sexes of 4-, 6-, and 8-week-old fed NOD mice, compared with sex- and age-matched fed C57BL/6 mice, taken as controls. We also assessed glucose tolerance in fasting 8-week-old NOD females and males, compared with sex- and age-matched fasting C57BL/6 mice. Finally, to demonstrate a possible relationship between the progression of insulitis and the appearance of ß-cell hyperactivity, we investigated glucose tolerance in younger NOD mice, which exhibited various degrees of insulitis.


   Materials and Methods
Top
 Abstract
 Introduction
 Materials and Methods
Results
 Discussion
 References
 
Animals
NOD mice (originally provided by Clea-Japan, Inc., Tokyo, Japan) and C57BL/6 mice were bred in our own facilities under pathogen-free conditions. NOD mice were antiviral antibody-free for 13 viruses, including diabetogenic viruses (31). All mice were maintained on a 12-h light, 12-h dark cycle with lights on from 0700 h to 1900 h, at 22 ± 1 C under laminar flow ventilation, and were given standard food pellets and water ad libitum. The animal facilities and care followed the norms stipulated by the European Community (32). In the experiments, fed or fasting female and male nondiabetic NOD mice (with basal nonfasting glycemia < 11 mmol/liter, as assessed by Glukotest, Boehringer-Mannheim, Mannheim, Germany) were used at 4, 6, and 8 weeks of age and compared with age- and sex-matched mice of our currently used control strain (28, 29, 33). In our NOD colony, during the time of this investigation, overt diabetes appeared at the 12th and 16th weeks of age for females and males, respectively, and 80% of the females and 40% of the males were diabetic at 6 months of age. The infiltration of the islets of Langerhans by inflammatory cells (insulitis) progressed slightly more rapidly in females than in males, as previously described (34).

Experimental protocol under basal conditions and for glucose tolerance test
For glucose tolerance determinations, overnight-fasted mice were injected ip with glucose (Assistance Publique, Paris, France), dissolved in 0.9% NaCl, at doses varying from 1–6 g/kg (19, 20, 22, 25, 26). For basal and glucose tolerance test determinations, all experiments started at 0900 h. In all cases, unanesthetized animals were bled in less than 2 min by retroorbital puncture. As previously shown, this technique avoids stress-induced metabolic changes, at least during the sampling time (29). In this study, mean values (± SEM, n = 6 mice per age group) of blood corticosterone concentrations were 39 ± 5, 51 ± 8, 20 ± 3, and 24 ± 3 ng/ml in 4- to 8-week-old NOD females, C57BL/6 females, NOD males, and C57BL/6 males, respectively, with the higher values observed in females reflecting the expected sexual dimorphism (29, 35, 36). In each series of experiments, different groups of animals were bled at different times to avoid the hyperglycemic effect of repeated orbital puncture (29). Blood samples were kept on ice and centrifuged at 13,000 x g for 2 min at 4 C and were stored at -20 C. Pancreata were rapidly removed, weighed, and homogenized in 15 ml cold acid ethanol extraction medium [1.5% (vol/vol) 1 N HCl in 75% ethanol]. After addition of another 10 ml extraction medium, the homogenates were centrifuged (800 x g for 15 min, 4 C), and the supernatants were left standing overnight at 4 C. The pH of the supernatants was adjusted to 8.5 with ammonium hydroxide and, after centrifugation (800 x g for 15 min, 4 C), 5 ml of each supernatant were stored at -20 C until assayed.

Glucose and insulin determinations
Glucose concentrations were measured using the glucose-oxidase method (Biotrol glucose enzymatic color, Biotrol, Paris, France). Insulin concentrations were determined using a standard RIA kit (SB-INSULIN CT, CIS BioInternational, Gif-sur-Yvette, France).

Statistical analyses
All data are means ± SEM. The differences between mean values of glucose and insulin were evaluated by means of a two-, three-, or four-P-factor ANOVA. Post hoc analysis, using the Newman-Keuls test, was done when the main effect and interaction were significant (P < 0.05), as assessed by ANOVA.


   Results
Top
 Abstract
 Introduction
 Materials and Methods
 Results
Discussion
 References
 
Body and pancreas weights, blood glucose and insulin concentrations, and pancreatic insulin contents, as a function of age
Figure 1Go (upper panel) shows body weight curves for both sexes of NOD and C57BL/6 mice at 4, 6, and 8 weeks of age. ANOVA revealed, among other effects and interactions, that strain, sex, and age affected body weight (P < 10-6 for each factor). Indeed, for both sexes at all ages investigated, NOD mice weighed significantly more than C57BL/6 mice (P < 0.00005 in all cases, by post hoc analyses). Moreover, for both strains, body weights of females were significantly lower than those of males at each age evaluated (P < 0.00005 by post hoc analyses), except 4-week-old C57BL/6 mice. Finally, body weight increased significantly as a function of age for both sexes of NOD and C57BL/6 mice, and this effect was significant at each age studied (P values from 0.02 to < 0.0005 by post hoc analyses).



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  		Figure 1. Body (upper panel), pancreas weights (middle panel), and the pancreas weight/body weight ratio (lower panel), as a function of age, for normally fed NOD ({diamondsuit}) and C57BL/6 ({square}) mice. Values are means ± SEM (n = 12 mice/age group). Strain, sex, and age affected body and pancreas weights (P < 10-6 in all cases, by ANOVA).

 
Pancreas weight curves for both sexes of 4-, 6-, and 8-week-old NOD and age-matched C57BL/6 mice also are shown in Fig. 1Go (middle panel). ANOVA indicated, among others, that strain, sex, and age affected pancreas weight (P < 10-6). For both sexes, at each age investigated, pancreas weights were significantly higher for NOD than C57BL/6 mice (P < 0.00002 in all cases, by post hoc analyses), except for 6-week-old females (P = 0.02). Pancreas weights were generally lower for females than males, with the effect being significant in 6-and 8-week-old NOD and C57BL/6 mice (P values from 0.002 to < 0.00002 by post hoc analyses). Pancreas weights also increased as a function of age, and this effect was seen for all groups of mice between 4 and 6 weeks and 6 and 8 weeks of age (P values from 0.02–0.00002 by post hoc analyses for all groups), except C57BL/6 females between 6 and 8 weeks of age. It should be mentioned that body and pancreas weights were systematically greater in NOD than in sex- and age-matched C57BL/6 mice. However, when the pancreas weight was normalized to body weight (Fig. 1Go, lower panel), there was no statistically significant difference between both strains.

Blood nonfasting glucose and insulin concentrations are shown for both sexes of NOD and C57BL/6 mice, as a function of age, in Fig. 2Go (upper panel). ANOVA revealed, among the various effects, that strain, sex, and age affected glycemia (P < 10-6 in all cases). First, at 6 and 8 weeks of age, in both females and males, glycemia values were significantly lower in NOD than in C57BL/6 mice (P values from 0.002–0.0003 by post hoc analyses). Second, in NOD mice, glycemia values were statistically significantly lower for females than males at 4 and 6 weeks of age (P = 0.003 and P = 0.00003, respectively, by post hoc analyses) but not at 8 weeks of age. In C57BL/6 mice, glycemia values were statistically lower for females than males at 6 and 8 weeks of age (P = 0.00002 and P = 0.04, respectively, by post hoc analyses) but not at 4 weeks of age. Third, while no significant effect of age was observed for females of both strains, it could be noted that, for males of both strains, glucose concentrations increased from 4–6 weeks of age (with the effect being significant only for C57BL/6 males, P = 0.00003 by post hoc analyses) and then decreased significantly from 6–8 weeks of age (P = 0.00001 and P = 0.002 for NOD and C57BL/6 males, respectively, by post hoc analyses).



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  		Figure 2. Basal nonfasting blood glucose (upper panel) and insulin (lower panel) concentrations, as a function of age, in NOD ({diamondsuit}) and C57BL/6 ({square}) mice. Blood glucose and insulin concentrations were measured with kits using the glucose-oxidase method and a standard RIA, respectively. Values are means ± SEM (n = 15 mice/age group). ANOVA revealed that strain, sex, and age affected glucose values (P < 10-6 in all cases) and that strain and age affected insulin values (P < 10-5 in both cases).

 
Concerning basal nonfasting insulin (Fig. 2Go, lower panel), ANOVA indicated, among others, that strain and age affected its concentrations (P < 10-5 in both cases). First, in females at the three ages investigated, basal blood insulin values were significantly higher in NOD than in C57BL/6 mice (P values from 0.001–0.00001 by post hoc analyses). For males, the same pattern was observed between the two strains, but it reached statistical significance only at 6 weeks of age (P = 0.00003 by post hoc analyses). Second, although at each age studied, there was no significant difference concerning basal blood insulin concentration values between C57BL/6 females and males, these values were significantly higher in NOD males than females at 6 weeks of age, and the opposite was found at 8 weeks of age (P = 0.0002 and P = 0.01, respectively, by post hoc analyses). Third, though there was no significant effect of age on blood insulin values in females of both strains, by contrast, these values peaked at 6 weeks of age in males, with the effect being statistically significant only for NOD males (P = 0.00002 when comparing 6-week-old to 4- or 8-week-old animals).

Pancreatic insulin contents are shown in Fig. 3Go. When expressed in nmol/pancreas (upper panel), ANOVA revealed that strain (P < 10-6), sex (P = 0.005), and age (P < 10-6) affected pancreatic insulin content. Pancreatic insulin contents expressed in nmol/pancreas were significantly higher in NOD than in C57BL/6 females at 4 and 6 weeks of age (P = 0.009 and P = 0.01, respectively, by post hoc analyses) and in 6-week-old NOD males than in C57BL/6 males (P = 0.007 by post hoc analyses). A sex effect was only observed for 8-week-old C57BL/6 mice; females exhibited significantly higher pancreatic insulin contents (nmol/pancreas) than males (P = 0.01 by post hoc analyses). Pancreatic insulin content also increased as a function of age, with the effect being significant from 4–6 weeks of age for NOD females, C57BL/6 females, and NOD males (P = 0.03, P = 0.03, and P = 0.01, respectively, by post hoc analyses) and from 6–8 weeks of age for C57BL/6 females (P = 0.008 by post hoc analyses). When expressed in pmol/mg of pancreas (Fig. 3Go, lower panel), ANOVA indicated that sex (P = 0.01) and age (P = 0.00002) influenced insulin pancreatic contents. Among NOD mice, females seemed to have higher insulin contents (pmol/mg of pancreas) than males at 4 and 6 weeks of age, but the effect was significant only at 6 weeks of age (P = 0.04 by post hoc analyses). For 4-week-old C57BL/6 mice, the opposite was found, with males showing higher insulin contents than females (P = 0.0002 by post hoc analyses). However, this effect disappeared rapidly, so that 6- and 8-week-old C57BL/6 females tended to exhibit higher insulin contents than males. Indeed, the C57BL/6 male insulin content, expressed in pmol/mg of pancreas, dropped sharply between 4 and 6 weeks of age (P = 0.0001 by post hoc analyses). Finally, 4-week-old C57BL/6 males had higher insulin contents (pmol/mg of pancreas) than age-matched NOD males (P = 0.0002 by post hoc analyses).



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  		Figure 3. Pancreatic insulin contents, as a function of age, in normally fed NOD ({diamondsuit}) and C57BL/6 ({square}). Results are expressed in nmol/pancreas (upper panel) or in pmol/mg of pancreas (lower panel) and are means ± SEM of 10 mice/age group. Insulin contents (nmol/pancreas) were significantly different between the two strains, in 4- and 6-week-old females and in 6-week-old males (P values from 0.009–0.01 by post hoc analyses).

 
Glucose tolerance tests
The kinetics of blood glucose and insulin concentrations in fasting 8-week-old NOD and C57BL/6 mice are shown in Fig. 4Go. Basal fasting glucose values (time zero) were 3.8 ± 0.5, 4.2 ± 0.5, 4 ± 0.5, and 4.3 ± 0.5 mmol/liter (means ± SEM, 18 mice/group) in NOD females, NOD males, C57BL/6 females, and C57BL/6 males, respectively. No significant differences were observed among the various groups. The effect of glucose, given at the single dose of 1 g/kg, was studied on blood glucose concentrations 5, 10, 30, 60, and 90 min after injection (Fig. 4Go, upper panel). ANOVA revealed that strain, sex, and time affected blood glucose concentrations (P < 10-5 for each factor). Moreover, there were strain x sex (P = 0.01), strain x time, and sex x time interactions (P < 10-6 in both cases). Indeed, for a given sex, the glucose-response pattern differed between the two strains: peak plasma glucose values were reached faster, at 5 min in NOD mice vs. 10 min in C57BL/6 mice. Ten minutes after glucose injection, glucose values were significantly higher in both sexes of C57BL/6 than in sex-matched NOD mice (P = 0.00003 and P = 0.00001 for females and males, respectively, by post hoc analyses). Moreover, in each strain, glucose concentrations returned less rapidly to basal values in males than females. This slower return to basal glucose levels in males was more pronounced in C57BL/6 mice (P values varying from 0.0001–0.04 at 30, 60, and 90 min, by post hoc analyses), whereas in NOD mice, the effect was only significant at 30 min (P = 0.01 by post hoc analyses).



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  		Figure 4. Kinetic studies of glucose tolerance in fasting 2-month-old NOD ({diamondsuit}) and C57BL/6 ({square}) females and males. Glucose (1 g/kg) was injected ip into mice that were bled at different times by retroorbital puncture. Values are means ± SEM of 18 mice at each time. Glucose values, 10 min after injection, were significantly higher in both sexes of C57BL/6 mice than in sex-matched NOD mice (P >= 0.0003 by post hoc analyses). Note a significant sexual dimorphism in insulin concentrations, at 5 min in NOD mice, with females exhibiting higher values than males (P < 10-5 by post hoc analyses).

 
Basal fasting insulin values (time zero) were 89 ± 58, 97 ± 88, 69 ± 27, and 73 ± 47 pmol/liter in NOD females, NOD males, C57BL/6 females, and C57BL/6 males, respectively (mean ± SEM, n = 18/group). No significant differences were observed among the various groups. With regard to blood insulin in response to glucose, ANOVA indicated that strain and time influenced its concentrations (P = 0.01 and P < 10-6, respectively). Moreover, there were strain x time, sex x time, and strain x sex x time interactions (P < 10-6, P = 0.0005 and P = 0.01, respectively). For NOD mice, as revealed by post hoc analyses, both time and sex affected insulin concentrations. Indeed, 5 min after glucose injection, insulin values were significantly increased, compared with time zero, in both females (P = 0.00003) and males (P = 0.0002). Moreover, there was a significant sexual dimorphism, with females exhibiting higher values than males (P < 10-5). For C57BL/6 mice, only time had an effect on insulin concentrations: these values were significantly higher 10 min after injection, compared with time zero (P = 0.009 and P = 0.0007 for females and males, respectively). Five minutes after injection, a significant strain difference was observed, with NOD mice showing higher values than sex-matched C57BL/6 mice (P = 0.00002 and P = 0.0001 for females and males, respectively).

The effects of various glucose doses (from 1–6 g/kg) on blood glucose and insulin concentrations in each strain were analyzed at 8 weeks of age, 5 and 10 min after injection being the respective time points of maximal responses in fasting NOD and C57BL/6 mice (Fig. 5Go). Saline was injected as the control. ANOVA indicated that strain, sex, and treatment influenced blood glucose concentrations (P < 10-6, P = 0.01, and P < 10-6, respectively) (Fig. 5Go, upper panel). Moreover, there was a strain x treatment interaction (P < 10-6). Indeed, blood glucose concentrations increased gradually in both sexes of both strains, with increasing doses of glucose (P values varying from 0.004–10-5 in each group, by post hoc analyses), and the effect was less pronounced in NOD than in C57BL/6 mice (P = 0.0001 and P = 0.00002 for females at 4 and 6 g/kg glucose, respectively; and P = 0.04, P = 0.0007, and P = 0.00002 for males at 2, 4, and 6 g/kg glucose, respectively, by post hoc analyses).



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  		Figure 5. Effect of administering various doses of glucose (from 1–6 g/kg) on glucose tolerance in fasting 2-month-old NOD and C57BL/6 females and males. Saline was used as the control. Blood glucose (upper panel) and insulin (lower panel) concentrations were determined in each strain, at the times of the maximal response in kinetic studies. Each bar represents the mean ± SEM of 10 mice in each group. Note: 1) a significant effect of strain, sex, and treatment on glucose concentrations (P < 10-6, P = 0.01, and P < 10-6, respectively, by ANOVA); and 2) a significant sex effect on insulin concentrations in NOD mice, at 1 and 6 g/kg of glucose (P = 0.0003 and P = 0.05, respectively, by post hoc analyses).

 
With regard to the insulin response to the various glucose concentrations (Fig. 5Go, lower panel), ANOVA indicated that strain, sex, and treatment affected its concentrations (P = 0.0003, P = 0.004, and P < 10-6, respectively). Moreover, there were strain x sex and strain x treatment interactions (P = 10-6 and P = 0.009, respectively). The observation that the sex effect differed according to the strain considered should be emphasized: for NOD mice, glucose administration led always to higher insulin concentrations in females than in males, with the effect being significant at 1 and 6 g/kg of glucose (P = 0.0003 and P = 0.05, respectively, by post hoc analyses). In C57BL/6 mice, the opposite effect seemed to be found, but it never reached statistical significance.

The effect of varying glucose concentrations on blood glucose and insulin concentrations in both sexes of 4-, 6-, and 8-week-old fasting NOD mice was also analyzed (Fig. 6Go). We previously demonstrated that 4-week-old NOD mice exhibit no insulitis, whereas 10–20% and 30–40% of the islets show signs of insulitis at 6 and 8 weeks of age, respectively (37, 38). ANOVA revealed that age and treatment affected blood glucose concentrations both individually and together (P < 10-6 in all cases) (Fig. 6Go, upper panel). Indeed, increases in glucose concentrations with increasing glucose doses were less marked at 4 than at 6 and 8 weeks of age in both sexes, with the effect being significant at all glucose doses (P values ranging from 0.02–0.00001 by post hoc analyses).



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  		Figure 6. Effect of administering various doses of glucose (from 1–6 g/kg) on glucose tolerance in fasting 4-, 6-, and 8-week-old NOD females and males. Saline was used as the control. Blood glucose (upper panel) and insulin (lower panel) concentrations were determined 5 min after glucose injection. Each bar represents the mean ± SEM of 10 mice in each group. The sexual dimorphism was already significant in 6-week-old NOD mice at all glucose doses except 6 mg (P values < 0.0001 by post hoc analyses).

 
Concerning the insulin response to various glucose concentrations in NOD mice of different ages, ANOVA indicated that sex, age, and treatment influenced its concentrations (P < 10-6 in all cases). Moreover, there were sex x age, sex x treatment, age x treatment, and sex x age x treatment interactions (P < 10-6, P = 0.0002, P < 10-6, and P = 0.02, respectively). According to post hoc analyses, sex had no significant influence on insulin secretion in 4-week-old mice, regardless of the glucose dose. By contrast, the sex effect was already present at 6 weeks of age, with females secreting significantly more insulin than males at all glucose doses except 6 mg (P values ranging from 0.0001–0.00001).


   Discussion
Top
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
References
 
Various parameters of glucose homeostasis were investigated in both sexes of prediabetic NOD mice, compared with sex- and age-matched C57BL/6 mice. First, we showed that nonfasting blood glucose concentrations were generally lower in both sexes of NOD mice, compared with controls, especially at 6 and 8 weeks of age. Notably, complementary ongoing experiments indicate that 8-week-old NOD mice of both sexes also exhibit, in the nonfasting state, lower glycemia than sex- and age-matched animals from other control strains, such as DBA/2 and BALB/c. Kinetic studies, after glucose loading, demonstrated that the profiles of blood glucose concentrations also differed between the two strains, with both sexes of NOD mice showing an earlier peak that seems to be less well sustained, compared with sex-matched C57BL/6 mice. Moreover, in dose-response studies, blood glucose levels were always lower in NOD than in C57BL/6 mice. A sex difference was also noted in both strains at various ages, with males in the basal nonfasting state showing higher blood glucose levels than females, and in kinetic experiments, with the slower return of male glucose concentrations to basal values, compared with strain-matched females. Another relevant feature is that basal glycemia peaked at 6 weeks of age in both strains but only in males. A sexual dimorphism in glucose homeostasis seems to have been observed classically, at least in rodents, as discussed below for insulin.

With regard to basal insulinemia in nonfasting animals, a marked strain difference was observed; this effect was particularly striking, at all ages, for females, with NOD mice having higher insulin levels than sex- and age-matched C57BL/6 mice. Therefore, at the prediabetic stage, the high NOD mouse basal insulinemia may be responsible for the low glycemia. It should be emphasized that blood insulin levels are extremely sensitive to environmental and experimental conditions. Therefore, extreme care in animal housing and bleeding (as assessed by corticosterone determinations) is needed to avoid the {alpha}2-adrenergic inhibitory effect of catecholamines on insulin secretion (29, 37). Our in vivo data, showing high basal insulin secretion in fed NOD mice, confirm data obtained in vitro using isolated islets from various mouse strains (38). Kinetic studies, after glucose loading, demonstrated that in both sexes of NOD mice, insulin levels peaked earlier than in sex-matched C57BL/6 mice. Moreover, prediabetic 8-week-old NOD females secreted, surprisingly, approximately twice as much insulin as NOD males in response to glucose (1 g/kg) loading, an effect that has been confirmed in dose-response studies and which differs from that observed in C57BL/6 mice. Indeed, in normal rodents, circulating insulin concentrations, under basal conditions and/or response to glucose, have generally been reported to be higher in males than in females, because of the presence of androgens, which induce a state of insulin resistance (28, 29, 39, 40, 41). However, it should be emphasized here that androgens may act on the progression of type I diabetes in a complex manner, by exerting both deleterious effects (via their antiinsulin action) and beneficial, immunosuppressive effects (42). Finally, in males of both strains, in parallel to what has been observed for glycemia, blood basal insulin concentrations peaked at 6 weeks of age. Moreover, the insulin response to glucose loading was enhanced at 6 (compared with 8) weeks of age in NOD females and also in NOD males, when considering the highest glucose dose administered. This effect can be linked to the hormonal changes that occur during the pubertal period. It is well known that insulin resistance occurs during puberty in normal and diabetic children of both sexes (43, 44, 45). Adrenal androgens, such as DHEA-s, and GH may be factors responsible for the decline in insulin sensitivity (44).

The finding of ß-cell hyperactivity, particularly in prediabetic NOD females, corroborates that of concomitant ß-cell hyperplasia (46). The cause of ß-cell hyperplasia in early prediabetes in NOD mice is unknown. In rat models of IDDM induced by partial pancreatectomy, various compensatory mechanisms are involved, including increases of ß-cell sensitivity and activity, ß-cell hyperplasia, and islet regeneration (47, 48, 49, 50, 51). Hypertrophy and regeneration of some islets of Langerhans is a normal feature of recent-onset human IDDM (52, 53). However, ß-cell loss does not seem to be responsible for the ß-cell hyperactivity observed at the various ages investigated here, because: 1) ß-cell loss is considered to be a late phenomenon in NOD mice (54, 55); and 2) pancreatic insulin contents (nmol/pancreas) were not lower. It should be emphasized that the decrease in pancreatic insulin content, which is observed when expressing the results in pmol/mg of pancreas, is linked to the striking growth of the exocrine pancreas after birth (56, 57). It is also interesting to note that, in NOD females, whereas significant hyperinsulinemia was observed under basal nonfasting conditions as early as 4 weeks of age, an increased response to glucose loading was only observed as of 6 weeks of age. The above observations should be interpreted in light of the following data: 1) A primary (genetic) ß-cell abnormality, taking into account the role of the insulin gene, and especially the variable number tandem repeat region in human IDDM (58, 59, 60), cannot be excluded. 2) The NOD female ß-cell hyperactivity in response to glucose loading seems to follow the appearance of insulitis, because it is not observed in 4-week olds, in which less than 1% of the islets exhibit insulitis (33). This ß-cell hyperactivity, therefore, may be linked to the production of cytokines, for example IL-1 (which, at low doses, is known to stimulate insulin secretion but is inhibitory at high doses) (61, 62, 63). In keeping with this mode of action, specific IL-1 receptors are located in the islets of Langerhans in prediabetic NOD mice (64). 3) In addition to androgens, estrogens are able to modulate glucose homeostasis. In rodents, estradiol treatment can induce hypoglycemia, raise plasma insulin (and sometimes, pancreatic insulin contents), increase the ß-cell response to glucose in vivo, and induce ß-cell hyperplasia (65, 66, 67). Furthermore, the adrenal glands seemed to be essential for the expression of these estradiol effects on ß-cells (67), and this observation is consistent with the particular sensitivity of the NOD mouse hypothalamo-pituitary-adrenal axis (28). It is possible to suggest that, in NOD females, estrogens and glucocorticoids may synergize with the stimulatory effect of cytokines on ß-cell hyperactivity.

As mentioned here, sex steroids exert multiple and complex effects at various levels of glucose homeostasis in normal animals. We showed previously that castration increases the incidence of the disease in NOD males, though having no effect in NOD females, results which were mainly interpreted in terms of immunosuppressive effects of androgens (31). However, because orchidectomy is also known to induce islet hypertrophy and increased insulin response to hyperglycemia, even in normal animals (68), it remains to be determined whether the effects of hormonal modulation on islet characteristics and glucose homeostasis play a direct role in the pathogenesis of the disease in NOD mice.

In conclusion, the notion of transient hyperactivity of some islets of Langerhans may be crucial in the context of the role of the target organ in the development of the disease (30). Indeed, the expression of autoantigen(s) in the islet of Langerhans is required in NOD mice for activation of T cells and diabetes transfer (69). Moreover, studies in humans and rodents suggest that prophylactic insulin treatment slows the progression of the disease, partly by inducing ß-cell rest (30, 70, 71, 72, 73). Hyperactive islets are known to express elevated levels of cell adhesion ligands, MHC molecules, and autoantigens, which may heighten the sensitivity of ß-cells to the cytotoxic effects of cytokines and precipitate diabetes onset (30, 74, 75). In this context, it is worth noting that the NOD-scid/scid mouse, which lacks functional lymphocytes and exhibits neither insulitis nor diabetes, is also characterized by the presence of mega-islets and dendritic/macrophage infiltration (46) and the same parameters of glucose homeostasis as those described here for the young prediabetic NOD mouse, i.e. low basal glycemia and high insulinemia in the nonfasting state (76). These results suggest that an early abnormality at the level of the islet of Langerhans may play a role in the pathogenesis of type I diabetes, but the presence of functional lymphocytes is necessary for progression toward true insulitis and overt diabetes. The clinical and immunological importance of this finding and its pathophysiological mechanism(s) remain to be resolved (77).


   Acknowledgments
 
The authors wish to thank Dr. D. Horrobin for his continuous interest and support. We also thank Véronique Alves, Maryline Calise, and Isabelle Cissé for technical assistance, and Catherine Slama for typing the manuscript.


   Footnotes
 
1 This work was supported by grants from ALFEDIAM (associated with Lilly and Boehringer-Mannheim Laboratories) and the Fondation de France. Back

Received June 20, 1997.


   References
Top
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
 References
 

  1. Yilmaz MT 1993 The remission concept in type 1 diabetes and its significance in immune intervention. Diabetes Metab Rev 9:337–348[Medline]
  2. Atkinson MA, MacLaren NK 1993 Islet cell autoantigens in insulin-dependent diabetes. J Clin Invest 92:1608–1616
  3. Lindgren FA, Hartling SG, Dahlquist GG, Binder C, Efendic S, Persson BE 1991 Glucose-induced insulin response is reduced and proinsulin response increased in healthy siblings of type 1 diabetic patients. Diabetic Med 8:638–643[Medline]
  4. Hollander PH, Asplin CM, Kniaz D, Hansen JA, Palmer JP 1982 Beta-cell dysfunction in nondiabetic HLA identical siblings of insulin-dependent diabetics. Diabetes 31:149–153[Abstract]
  5. Heaton DA, Millward BA, Gray P, Tun Y, Hales CN, Pyke DA, Leslie RDG 1987 Evidence of ß-cell dysfunction which does not lead on to diabetes: a study of identical twins of insulin dependent diabetics. Br Med J 294:145–146
  6. Lo SSS, Hawa M, Beer SF, Pyke DA, Leslie RDG 1992 Altered islet beta-cell function before the onset of type 1 (insulin-dependent) diabetes mellitus. Diabetologia 35:277–282[CrossRef][Medline]
  7. Vialettes B, Zevaco-Mattei C, Thirion X, Lassmann-Vague V, Pieron H, Mercier P, Vague P 1993 Acute insulin response to glucose and glucagon in subjects at risk of developing type I diabetes. Diabetes Care 16:973–977[Abstract]
  8. Srikanta S, Ganda OP, Gleason RE, Jackson RA, Soeldner JS, Eisenbarth GS 1984 Pre-type I diabetes. Linear loss of beta cell response to intravenous glucose. Diabetes 33:717–720[Abstract]
  9. Heaton DA, Millward BA, Gray IP, Tun Y, Hales CN, Pyke DA, Leslie RDG 1988 Increased proinsulin levels as an early indicator of B-cell dysfunction in non-diabetic twins of type 1 (insulin-dependent) diabetic patients. Diabetologia 31:182–184[CrossRef][Medline]
  10. Hartling SG, Lindgren F, Dahlqvist G, Persson B, Binder C 1989 Elevated proinsulin in healthy siblings of IDDM patients independent of HLA identity. Diabetes 38:1271–1274[Abstract]
  11. Heding LG, Ludvigsson J, Kasperska-Czyzykowa T 1981 B-cell secretion in non-diabetics and insulin-dependent diabetics. Acta Med Scand 656:5–9
  12. Roder ME, Knip M, Hartling SG, Karjalainen J, Akerblom HK, Binder C, The Childhood Diabetes in Finland Study Group 1994 Disproportionately elevated proinsulin levels precede the onset of insulin-dependent diabetes mellitus in siblings with low first phase insulin responses. J Clin Endocrinol Metab 79:1570–1575[Abstract]
  13. Snorgaard O, Hartling SG, Binder C 1990 Proinsulin and C-peptide at onset and during 12 months cyclosporin treatment of type 1 (insulin-dependent) diabetes mellitus. Diabetologia 33:36–42[CrossRef][Medline]
  14. Spinas GA, Snorgaard O, Hartling SG, Oberholzer M, Berger W 1992 Elevated proinsulin levels related to islet cell antibodies in first-degree relatives of IDDM patients. Diabetes Care 15:632–637[Abstract]
  15. Baudon MA, Ferre P, Penicaud L, Maulard P, Ktorza A, Castano L, Girard J 1989 Normal insulin sensitivity during the phase of glucose intolerance but insulin resistance at the onset of diabetes in the spontaneously diabetic BB rat. Diabetologia 32:839–844[CrossRef][Medline]
  16. Kanazawa M, Ikeda J, Sato J, Natoya Y, Ito H, Komeda K, Kawazu S, Kanazawa Y 1988 Alteration of insulin and glucagon secretion from the perfused BB rat pancreas before and after the onset of diabetes. Diabetes Res Clin Pract 5:201–204[CrossRef][Medline]
  17. Pederson RA, Curtis SB, Chisholm CB, Gaba NRA, Campos RV, Brown JC 1991 Insulin secretion and islet endocrine cell content at onset and during the early stages of diabetes in the BB rat: effect of the level of glycemic control. Can J Physiol Pharmacol 69:1230–1236[Medline]
  18. Pedersen CR, Bock T, Hansen SV, Hansen MW, Buschard K 1994 High juvenile body weight and low insulin levels as markers preceding early diabetes in the BB rat. Autoimmunity 17:261–269[Medline]
  19. Nakhooda AF, Like AA, Chappel CI, Wei CN, Marliss EB 1978 The spontaneously diabetic Wistar Rat (the "BB" rat). Studies prior to and during development of the overt syndrome. Diabetologia 14:199–207[CrossRef][Medline]
  20. Nakhooda AF, Poussier P, Marliss EB 1983 Insulin and glucagon secretion in BB wistar rats with impaired glucose tolerance. Diabetologia 24:58–62[Medline]
  21. Grill V, Herberg L 1983 Glucose- and arginine-induced insulin and glucagon responses from the isolated perfused pancreas of the BB-Wistar diabetic rat. Evidence for selective impairment of glucose regulation. Acta Endocrinol (Copenh) 102:561–566[Medline]
  22. Nonaka Y, Yamada K, Miyazaki A, Tarui S 1984 Changes in insulin and glucagon contents in the NOD mouse. Their relevance to the development of insulin-dependent diabetes mellitus. In: Shafrir E, Renold AE (eds) Lessons from Animal Diabetes. John Libbey, London, pp 337–342
  23. Kano Y, Kanatsuna T, Nakamura N, Kitagawa Y, Mori H, Kajiyama S, Nakano K, Kondo M 1986 Defect of the first-phase insulin secretion to glucose stimulation in the perfused pancreas of the nonobese diabetic (NOD) mouse. Diabetes 35:486–490[Abstract]
  24. Ohneda A, Kobayashi T, Nihei J, Tochino Y, Kanaya H, Makino S 1984 Insulin and glucagon in spontaneously diabetic non-obese mice. Diabetologia 27:460–463[CrossRef][Medline]
  25. Strandell E, Sandler S, Boitard C, Eizirik DL 1992 Role of infiltrating T cells for impaired glucose metabolism in pancreatic islets isolated from non-obese diabetic mice. Diabetologia 35:924–931[CrossRef][Medline]
  26. Reddy S, Liu W, Thompson JMD, Bibby NJ, Elliott RB 1992 First phase insulin release in the non-obese diabetic mouse: correlation with insulitis, beta cell number and autoantibodies. Diabetes Res Clin Pract 17:17–25[CrossRef][Medline]
  27. Teruya M, Takei S, Forrest LE, Grunewald A, Chan EK, Charles MA 1993 Pancreatic islet function in nondiabetic and diabetic BB rats. Diabetes 42:1310–1317[Abstract]
  28. Amrani A, Jafarian-Tehrani M, Mormede P, Durant S, Pleau JM, Haour F, Dardenne M, Homo-Delarche F 1996 Interleukin-1 (IL-1) effect on glycemia in the nonobese diabetic (NOD) mouse at the prediabetic stage. J Endocrinol 148:139–148[Abstract]
  29. Amrani A, Chaouloff F, Mormede P, Dardenne M, Homo-Delarche F 1994 Glucose, insulin and open-field responses to immobilization in nonobese diabetic (NOD) mice. Physiol Behav 56:241–246[CrossRef][Medline]
  30. Homo-Delarche F, Boitard C 1996 Autoimmune diabetes: the role of the islets of Langerhans. Immunol Today 17:456–460[CrossRef][Medline]
  31. Fitzpatrick F, Lepault F, Homo-Delarche F, Bach JF, Dardenne M 1991 Influence of castration, alone or combined with thymectomy, on the development of diabetes in the nonobese diabetic mouse. Endocrinology 129:1382–1390[Abstract]
  32. Durant S, Coulaud J, Amrani A, El Hasnaoui A, Dardenne M, Homo-Delarche F 1993 Effects of various environmental stress paradigms and adrenalectomy on the expression of autoimmune type 1 diabetes in the non-obese diabetic (NOD) mouse. J Autoimmun 6:735–751[CrossRef][Medline]
  33. Saravia-Fernandez F, Faveeuw C, Blasquez-Bulant C, Tappaz M, Throsby M, Pelletier G, Vaudry H, Dardenne M, Homo-Delarche F 1996 Localization of gamma-aminobutyric acid and glutamic acid decarboxylase in the pancreas of the nonobese diabetic mouse. Endocrinology 137:3497–3506[Abstract]
  34. Durant S, Alves V, Coulaud J, El Hasnaoui A, Dardenne M, Homo-Delarche F 1995 Attempts to pharmacologically modulate prolactin levels and type 1 autoimmune diabetes in the nonobese diabetic (NOD) mouse. J Autoimmun 8:875–885[CrossRef][Medline]
  35. Kitay JI 1961 Sex differences in adrenal cortical secretion in the rat. Endocrinology 68:818–824
  36. Patchev VK, Hayashi S, Orikasa C, Almeida OFX 1995 Implications of estrogen-dependent brain organization for gender differences in hypothalamo-pituitary-adrenal regulation. FASEB J 9:419–423[Abstract/Free Full Text]
  37. Havel PJ, Taborsky GJ 1989 The contribution of the autonomic nervous system to changes of glucagon and insulin secretion during hypoglycemic stress. Endocr Rev 10:332–350[Medline]
  38. Eizirik DL, Welsh M, Strandell E, Welsh N, Sandler S 1990 Interleukin-1 depletes insulin messenger ribonucleic acid and increases the heat shock protein hsp70 in mouse pancreatic islets without impairing the glucose metabolism. Endocrinology 127:2290–2297[Abstract]
  39. Leiter EH 1988 Control of spontaneous glucose intolerance, hyperinsulinemia, and islet hyperplasia in nonobese C3H.SW male mice by Y-linked locus and adrenal gland. Metabolism 37:689–696[CrossRef][Medline]
  40. Leiter EH 1989 The genetics of diabetes susceptibility in mice. FASEB J 3:2231–2241[Abstract]
  41. Lavine RL, Chick WL, Like AA, Makdisi TW 1971 Glucose tolerance and insulin secretion in neonatal and adult mice. Diabetes 20:134–139
  42. Homo-Delarche F, Durant S 1994 Hormones, neurotransmitters and neuropeptides as modulators of lymphocyte functions. In: Rola-Pleszczynski M (ed) Immunopharmacology of Lymphocytes. Academic Press, London, pp 171–240
  43. Amiel SA, Sherwin RS, Simonson DC, Lauritano AA, Tamborlane WV 1986 Impaired insulin action in puberty. A contributing factor to poor glycemic control in adolescents with diabetes. New Engl J Med 315:215–219[Abstract]
  44. Bloch CA, Clemons P, Sperling MA 1987 Puberty decreases insulin sensitivity. J Pediatr 110:481–487[CrossRef][Medline]
  45. Bergstrom E, Hernell O, Persson LA, Vessby B 1996 Insulin resistance syndrome in adolescents. Metabolism 45:908–914[CrossRef][Medline]
  46. Jansen A, Rosmalen JGM, Homo-Delarche F, Dardenne M, Drexhage HA 1996 Effect of prophylactic insulin treatment on the number of ER-MP23+ macrophages in the pancreas of NOD mice. Is the prevention of diabetes based on ß-cell rest ? J Autoimmun 9:341–348[CrossRef][Medline]
  47. Leahy JL 1996 Impaired ß-cell function with chronic hyperglycemia: "overworked ß-cell" hypothesis. Diabetes Rev 4:298–319
  48. Bonner-Weir S 1994 Regulation of pancreatic beta-cell mass in vivo. In: Bardin CW (ed) Recent Progress in Hormone Research. Academic Press, New York, pp 91–104
  49. Swenne I 1992 pancreatic beta-cell growth and diabetes mellitus. Diabetologia 35:193–201[CrossRef][Medline]
  50. Orland MJ, Chyn R, Permutt MA 1985 Modulation of proinsulin messenger RNA after partial pancreatectomy in rats. Relationships to glucose homeostasis. J Clin Invest 75:2047–2055
  51. Homo-Delarche F 1997 ß-cell behavior during the prediabetic stage. 1. ß-cell pathophysiology. Diabete Metab 23:181–196[Medline]
  52. Gepts W 1983 Pathology of IDDM in man. Diabetes. Excerpta Medica, Amsterdam, pp 99–106
  53. Foulis AK, Stewart JA 1984 The pancreas in recent-onset type 1 (insulin-dependent) diabetes mellitus: insulin content of islets, insulitis, and associated changes in the exocrine acinar tissue. Diabetologia 26:456–461[Medline]
  54. Debussche X, Lormeau B, Boitard C, Toublanc M, Assan R 1994 Course of pancreatic ß-cell destruction in prediabetic NOD mice: a histomorphometric evaluation. Diabete Metab 20:282–290[Medline]
  55. Shimada A, Charlton B, Taylor-Edwards C, Fathman CG 1996 ß-cell destruction may be a late consequence of the autoimmune process in nonobese diabetic mice. Diabetes 45:1063–1067[Abstract]
  56. Dore BA, McLean Grogan W, Madge GE, Webb SR 1981 Biphasic development of the postnatal mouse pancreas. Biol Neonate 40:209–217[Medline]
  57. Werlin SL, Colton DG, Virojanavat S, Reynolds E 1987 DNA and protein synthesis in developing rat pancreas. Pediatr Res 22:34–38[Medline]
  58. Owerbach D, Gabbay KH 1996 Perspectives in diabetes. The search for IDDM susceptibility genes. The next generation. Diabetes 45:544–551[Abstract]
  59. Catignani-Kennedy G, German MS, Rutter WJ 1995 The minisatellite in the diabetes susceptibility locus IDDM2 regulates insulin transcription. Nat Genet 9:293–298[CrossRef][Medline]
  60. Lucassen AM, Screaton GR, Julier C, Elliott TJ, Lathrop M, Bell JI 1995 Regulation of insulin gene expression by the IDDM associated, insulin locus haplotype. Hum Mol Genet 4:501–506[Abstract/Free Full Text]
  61. Molvig J 1992 A model of the pathogenesis of insulin-dependent diabetes mellitus. Dan Med Bull 39:509–541[Medline]
  62. Purrello F, Buscema M 1993 Effects of interleukin-1ß on insulin secretion by pancreatic beta-cells. Diabetes Nutr Metab 6:295–304
  63. Mandrup-Poulsen T, Zumsteg U, Reimers J, Pociot F, Morch L, Helqvist S, Dinarello CA, Nerup J 1993 Involvement of interleukin 1 and interleukin 1 antagonist in pancreatic ß-cell destruction in insulin-dependent diabetes mellitus. Cytokine 5:185–191[CrossRef][Medline]
  64. Jafarian-Tehrani M, Amrani A, Homo-Delarche F, Marquette C, Dardenne M, Haour F 1995 Localization and characterization of interleukin-1 receptors in the islets of Langerhans from control and nonobese diabetic (NOD) mice. Endocrinology 136:609–613[Abstract]
  65. Bailey CJ, Ahmed-Sorour H 1980 Role of ovarian hormones in the long-term control of glucose homeostasis. Effects on insulin secretion. Diabetologia 19:475–481[CrossRef][Medline]
  66. Lenzen S, Bailey CJ 1984 Thyroid hormones, gonadal and adrenocortical steroids and the function of the islets of Langerhans. Endocr Rev 5:411–434[Abstract]
  67. Faure A, Sutter-Dub MT, Sutter BCJ, Assan R 1983 Ovarian-adrenal interactions in regulation of endocrine pancreatic function in the rat. Diabetologia 24:122–127[CrossRef][Medline]
  68. Renaud A, Sverdlik RC, Fels RC, Von Lawzewitsch I, Perez RL, Foglia VG, Rodriguez RR 1980 Metabolic and histological pancreatic changes induced by orchidectomy in dogs. Horm Metab Res 12:370–376[Medline]
  69. Larger E, Becourt C, Bach JF, Boitard C 1995 Pancreatic islet beta cells drive T cell-immune responses in the nonobese diabetic mouse model. J Exp Med 181:1635–1642[Abstract/Free Full Text]
  70. Schloot N, Eisenbarth GS 1995 Isohormonal therapy of endocrine autoimmunity. Immunol Today 16:289–294[CrossRef][Medline]
  71. Keller RJ, Eisenbarth GS, Jackson RA 1993 Insulin prophylaxis in individuals at high risk of type I diabetes. Lancet 341:927–928[CrossRef][Medline]
  72. Atkinson MA, MacLaren NK, Luchetta R 1990 Insulitis and diabetes in NOD mice reduced by prophylactic insulin therapy. Diabetes 39:933–937[Abstract]
  73. Gottlieb PA, Handler ES, Appel MC, Greiner DL, Mordes JP, Rossini AA 1991 Insulin treatment prevents diabetes mellitus but not thyroiditis in RT6-depleted diabetes resistant BB/Wor rats. Diabetologia 34:296–300[CrossRef][Medline]
  74. Aaen K, Rygaard J, Josefsen K, Petersen H, Brogren CH, Horn T, Buschard K 1990 Dependence of antigen expression on functional state of ß-cells. Diabetes 39:697–701[Abstract]
  75. Buschard K 1991 The functional state of the beta cells in the pathogenesis of insulin-dependent diabetes mellitus. Autoimmunity 10:65–69[Medline]
  76. Homo-Delarche F, Durant S, Throsby M, Amrani A, Coulaud J, Dardenne M 1997 Elements modulating glucose homeostasis in the NOD mouse at the prediabetic stage. Exp Clin Endocrinol Diabetes 105:27–28
  77. Homo-Delarche F 1997 ß-cell behavior during the prediabetic stage. II. Non insulin-dependent and insulin-dependent diabetes mellitus. Diabetes Metab (Paris) 23:473–505[Medline]



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