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Age-Dependent Inability of the Endocrine Pancreas to Adapt to Pregnancy: A Long-Term Consequence of Perinatal Malnutrition in the Rat¹

INSERM U 457, Hôpital Robert Debré, 75019 Paris, France

Address all correspondence and requests for reprints to: Dr. B. Bréant, INSERM U 457, Hôpital Robert Debré, 48 Boulevard Sérurier, 75019 Paris, France. E-mail: bbreant{at}infobiogen.fr

	Abstract

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We have recently shown that maternal food restriction during late pregnancy decreased ß-cell mass in the offspring at birth. Prolonged maternal malnutrition until weaning led to irreversible decrease of ß-cell mass in the adult male progeny. During pregnancy, the maternal endocrine pancreas demonstrates an acute and reversible increase in ß-cell mass. The aim of this work was to investigate whether perinatal malnutrition could have long-lasting effects on glucose homeostasis and the adaptation of the endocrine pancreas to a subsequent pregnancy. This study was conducted on 4- and 8-month-old female rats malnourished during their perinatal life and on age-matched control animals. Oral glucose tolerance tests (OGTT), pancreatic insulin content, and islet mass quantitation after dithizone staining were performed on the same animals. Four-month-old nonpregnant previously malnourished animals showed normal glucose tolerance but a significant decrease in insulin secretion during OGTT. These animals were, however, still able to adapt pancreatic insulin contents and doubled their islet mass in late gestation. At 8 months of age, insulin content before pregnancy was reduced to half that of controls. Moreover, it did not show the characteristic increase during gestation that could still be observed in pregnant control females. In those control animals, the islet mass increased regularly until late gestation (14.1 ± 1.8 mg at day 20.5, vs. 9.8 ± 1.2 mg, nonpregnant), whereas in previously malnourished animals the islet mass remained throughout pregnancy similar to the nonpregnant values (8.5 ± 1.4 mg at day 20.5 vs. 8.9 ± 3.6 mg, nonpregnant). In conclusion, early malnutrition has dramatic consequences on the capacity of the endocrine pancreas to meet the increased insulin demand during pregnancy and aging.

	Introduction

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INTRA-UTERINE and early postnatal malnutrition have profound consequences on fetal and postnatal development, both in humans and animals (1, 2). More specifically, we (3) and others (4) have shown that animals subjected in utero to general protein/calorie malnutrition (3) or protein deficiency only (4) have, at birth, fewer ß cells or decreased islet volume, respectively. Furthermore, prolonged maternal undernutrition until the end of lactation decreased ß-cell mass by 70% at day 21 postnatal in the male progeny, which was not fully restored at adult age by refeeding normally from weaning (5). These observations were of interest because of the known association shown in humans between poor fetal/neonatal growth and development of hypertension, glucose intolerance, insulin resistance, and dyslipidemia later in life (6, 7, 8, 9). The mechanisms linking low birth weight and glucose intolerance are not understood at present, but an exciting hypothesis proposed that poor nutrition in utero imposes the fetus to become thrifty at a time when ß-cell development proceeds more rapidly, which would result in impaired growth of these cells and predispose the individual to the development of diabetes later in life (10). As long as the undernourished state persists, there is no need to increase insulin production. A sudden move to overnutrition, by triggering insulin production in the ß cells, would render them more susceptible to exhaustion.

Interestingly, in previously malnourished rats, the finding that ß-cell mass was not fully restored at adult age, despite normal nutrition from weaning, was associated with decreased plasma insulin but normal plasma glucose (5). It has also been shown that maternal protein deficiency does not lead to impaired glucose tolerance in the adult offspring (11). Situations of increased insulin demand, such as high fat diets, aging, or pregnancy that can easily be reproduced in animal models might be necessary to reveal any vulnerability of the ß cell contracted after early undernutrition. Indeed, in previously protein-restricted rats, glucose tolerance was impaired when the animals were fed a high fat diet at adult age and more so than in high fat fed controls (12). It was therefore of interest to study if ß cells from previously malnourished animals were able to adapt to a situation of increased insulin demand. During normal pregnancy, the maternal endocrine pancreas demonstrates acute and reversible adaptive changes that include a lower glucose stimulation threshold (13), increased insulin synthesis (14) and secretion, and enhanced proliferation rate in the ß cells (13, 15, 16). In rats, these adaptations peaking around day 14 of pregnancy have been demonstrated to be controlled by placental lactogens I and II (13, 17, 18, 19) and allow the maternal ß-cell mass to nearly double at the end of gestation (20, 21). The aim of the present study was thus to investigate whether fetal and early postnatal malnutrition could have long lasting effects on glucose homeostasis at adult age and adaptation of the endocrine pancreas to a subsequent pregnancy. The potential worsening effect of age was also studied. For that purpose, female offspring from protein/calorie undernourished mothers were fed ad libitum from weaning and studied at 4 and 8 months of age, nonpregnant and at various stages of pregnancy. In each group, oral glucose tolerance tests, insulin content and islet mass quantitation after dithizone staining were performed.

	Materials and Methods

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Animals and study design
Female Wistar rats on day 5 of pregnancy (Janvier Breeding Centre, Le Genêt-St-Isle, France) were housed individually and maintained under a 12-h (0700–1900) light-dark cycle and constant temperature (22 C). All animals were fed a standard laboratory rat chow (no. 113, 22% protein, 5% fat, 53% carbohydrates; UAR, Villemoisson sur Orge, France) with free access to tap water. Every pregnant dam was weighed upon its arrival and randomly assigned to control or restricted group. Control pregnant dams were fed ad libitum, whereas pregnant dams from the restricted group were fed 50% (12 g) of the daily intake of pregnant control dams from day 15 of pregnancy. Maternal food restriction was continued until the end of lactation (22). At parturition, all pups were weighed before suckling, and those born from restricted mothers and showing a severe intrauterine growth retardation (IUGR) (body weight < control weight - 2SD) were selected. Litter size was equalized out to 8. After weaning, all pups were fed ad libitum until adulthood. Control and IUGR adult female offspring were studied at 4 months and 8 months of age before and during pregnancy. They were mated overnight with control male Wistar rats, and the day on which vaginal plugs were observed was designated day 0 of pregnancy. Pregnant females were caged individually and studied at days 17.5 and 20.5 of pregnancy, in comparison with nonpregnant females. Litter size decreased with age in both groups but was not different between the two groups: 13 ± 4 and 13 ± 2 fetuses in 4-month-old controls and previously malnourished females, respectively; 8 ± 5 and 6 ± 4 fetuses in 8- month-old controls and previously malnourished females, respectively.

The laboratory has an agreement for laboratory animal care facilities, delivered by the Agricultural Ministery (authorization no. 7612).

Oral glucose tolerance test (OGTT)
OGTT was performed on 12 animals from both groups at both ages after a 6-h fasting. Animals were given 2 g glucose/kg body weight with an oral canula. Blood samples were collected from the tail vein into heparinized tubes 5 min before (time 0) and 15, 30, 60, and 120 min after glucose load. Blood glucose was measured using a glucometer (One Touch II, Lifescan, Roissy, France). Plasma aliquots were kept at -20 C until assayed for insulin. The Area Under the Curve (AUC) was calculated for glycemic and plasma insulin values for each animal.

Pancreas sampling and islet staining
Animals were killed by cervical dislocation. Pancreata were quickly removed, weighed, and cut into 25 numbered samples. Every third sample was taken, generating 9–10 samples that were gathered and weighed for pancreatic insulin content determination. This sampling method has proved to be representative of the whole pancreatic insulin content. Insulin was extracted overnight in 10 ml of cold acidified ethyl alcohol (1,5% HCl, 75% EtOH) at -20 C. The extracts were stored at -20 C until assayed for insulin.

The rest of the pancreas was minced into small pieces during 10 min in a solution of dithizone (diphenylthiocarbazone, Sigma Chemical Co., St. Louis, MO) at a final concentration of 33 mg/ml as described (23) (24) (21). This procedure is based on the formation of colored complexes between dithizone and Zn²⁺ within the pancreatic islets. The tissue pieces were washed twice in PBS and immersed in 87% glycerol. They were whole mounted on glycerol containing 150-µm spacer slides (DAKO Corp., Trappes, France) and slightly flattened out with coverslips that were secured by nail polish. Slides were kept at -20 C until further analysis. This simple procedure allowed for the direct measurement of islet mass, islet size distribution, and insulin content from the same animal, avoiding the fixation, embedding and sectioning steps of immunohistochemistry.

Morphometric analysis
To measure the pancreatic endocrine mass, three slides (out of eight to ten) were randomly selected per animal. Computer assisted measurements were done using a Leica (Leica, Reuil-Malmaison, France) DMRB microscope equipped with a color video camera coupled to a Quantimet 500MC computer (screen magnification x24). The entire dithizone-stained area was measured on the three slides (final magnification, x60), and the pancreatic tissue area was similarly measured using the natural pancreatic staining. The percentage of endocrine tissue was then calculated as the ratio of the sum of the dithizone-stained area to the sum of the pancreatic tissue area. The endocrine mass was obtained for each pancreas by multiplying the percentage of endocrine tissue by the total pancreatic weight (mg). For the purpose of evaluating the distribution of islet sizes, islets were arbitrarily classified as small (25 µm < diameter < 100 µm), medium (101 µm < diameter < 150 µm) or large (151 µm < diameter < 600 µm) as described (21). The number of islets in each class was expressed as the percentage of total islet number per group and time point. Computer analysis also allowed the measurement of mean islet area and islet number, expressed as islet number/cm². Three to five animals were studied per time point in each group and at both ages.

Insulin determination
Immunoreactive insulin was measured with an RIA, using monoiodated ¹²⁵I-labeled porcine insulin (Sorin Biomedica, Sallugia, Italy) as a tracer, guinea pig antiinsulin antibody kindly provided by Dr. Van Schravendijk (Brussels, Belgium) and purified rat insulin (Novo Nordisk, Boulogne, France) as standard. Charcoal was used to separate free from bound hormone. The sensitivity of the assay was 0.25 ng/ml (6 µU/ml).

Statistical analysis
Values are expressed as mean ± SD. Differences between two groups were analyzed by an unpaired Student’s t test or by ANOVA when there was more than two groups. A P value < 0.05 was considered significant.

	Results

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Effect of age on female rat development and ß-cell function before pregnancy
Although weaned onto a control diet, adult females malnourished during their perinatal life show irreversible growth retardation (Table 1), as already shown for male offspring (22), with no further increase in body weight after 4 months of age. At 8 months of age, previously malnourished females showed 40% decreased insulin content, both per pancreas and per kg body weight, decreased fasting insulinemia but normal fasting glycemia. Although already noticeable at 4 months the differences were not statistically significant at that age (Table 1). The analysis of the AUC for plasma insulin and blood glucose values during an oral glucose tolerance test (Fig. 1 and Table 1) demonstrated a significant decrease in insulin secretion in previously malnourished females, as compared with controls, at both ages, yet glucose tolerance was moderately affected.

View larger version (28K): [in this window] [in a new window]   Figure 1. Effect of aging on blood glucose and insulin values during an OGTT in control (solid lines) and previously malnourished (dotted lines) nonpregnant females. Values are mean ± SD from 12 animals per group and age. *, P < 0.05 compared with controls of the same age.

Evolution of pancreatic insulin contents during pregnancy in 4- and 8-month-old animals
In 4-month-old control females, pancreatic insulin contents increased significantly with pregnancy and high pancreatic insulin levels were maintained until day 20.5 of pregnancy. Although the values were slightly lower at each time point, similar findings were observed in previously malnourished females, indicating at that age an adaptation of insulin contents to pregnancy (Fig. 2, top). At 8 months of age, control animals increased until day 17.5 their insulin content, which returned to nonpregnant values by day 20.5 of pregnancy, a marked difference with 4-month-old animals. On the contrary, in 8-month-old females that had been malnourished during their perinatal life, insulin contents at day 17.5 and 20.5 of pregnancy were not statistically different from nonpregnant values, demonstrating no adaptation of insulin contents to pregnancy (Fig. 2, bottom).

View larger version (33K): [in this window] [in a new window]   Figure 2. Evolution of insulin content during pregnancy in 4- and 8 month-old control (C) and previously malnourished (PM) females. Insulin content was measured by RIA in pancreases from nonpregnant animals (NP) and at day 17.5 (P17.5) and 20.5 (P20.5) of pregnancy. Values are mean ± SD from 3–5 pancreases analyzed per group and age. *, P < 0.05; ** P 0.01, compared with controls of the same age. °°, P 0.01, compared with nonpregnant animals of same group and age.

View larger version (28K): [in this window] [in a new window]   Figure 3. Evolution of islet mass during pregnancy in 4- and 8 month-old control (C) and previously malnourished (PM) females. Islet mass was morphometrically quantified after dithizone-staining on pancreatic pieces from nonpregnant (NP) animals and at day 17.5 (P17.5) and 20.5 (P20.5) of pregnancy, from the same animals as Fig. 2. Values are mean ± SD. **, P 0.01, compared with controls of the same age. °, P < 0.05; °°, P 0.01, compared with nonpregnant animals of same group and age.

Evolution of islet number/cm² and islet size distribution with pregnancy
To determine if the absence of adaptation of islet mass to pregnancy in 8-month-old previously malnourished females resulted from an alteration in islet size or islet number, the number of islets/cm² as well as the islet size distribution were quantified, both in nonpregnant and pregnant animals. In 8-month-old animals that had been malnourished during their perinatal life, the number of islets/cm² was decreased at days 17.5 (P < 0.05) and 20.5 of pregnancy, reaching only 50% of control values at that stage of pregnancy (p 0.01 vs. pregnant-20.5 controls, Fig. 4).

View larger version (36K): [in this window] [in a new window]   Figure 4. Evolution of the number of islets during pregnancy in 8-month-old control (C) and previously malnourished (PM) females. The number of islets was measured on pancreas from nonpregnant (NP) animals and at day 17.5 (P17.5) and 20.5 (P20.5) of pregnancy and expressed as islet number/cm2. Values (mean ± SD) are obtained from the same pancreata as in Fig. 3. *, P < 0.05; **, P 0.01 compared with controls.

View larger version (29K): [in this window] [in a new window]   Figure 5. Relative distribution of islet size in 8-month-old control (upper panel) and previously malnourished (bottom panel) animals as a function of pregnancy. Islets were classified as small (25 µm < diameter < 100 µm), medium (101 µm < diameter < 150 µm) or large (151 µm < diameter < 600 µm). Values (mean ± SD) are obtained from the same pancreata as in Fig. 3, from nonpregnant females (solid bars) and females at 20.5 of pregnancy (hatched bars). °, P < 0.05; °°, P 0.01; °°°°, P 0.0001, compared with nonpregnant females of the same group. No significant difference in islet size distribution was found between control and previously malnourished females.

	Discussion

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Numerous studies in humans and animals have shown that aging is generally associated with deterioration of insulin secretion, insulin resistance, and glucose intolerance (25, 26, 27, 28). Malnutrition during the perinatal period induces irreversible growth retardation in female offspring, as previously described for the male progeny (22). Moreover, this study shows that early malnutrition has dramatic consequences on ß-cell function when the increased insulin demand of age is placed on the ß cells. Malnutrition also prevented the increase of islet mass still observed in nonpregnant control animals between 4 and 8 months of age. Though the islet mass at 8 months of age was not significantly reduced in previously malnourished females compared with controls, there was a strong decrease in the insulin stores, fasting insulin was decreased, and secretory response to glucose was impaired before pregnancy.

Pregnancy, another physiological situation of increased insulin demand, is characterized by a reversible increase of ß-cell mass, which involutes afterwards within few days after delivery in rats (20, 21, 29). This adaptive process has been quantitatively studied after dithizone staining in females that had been malnourished during the perinatal life. Staining the islets with dithizone, either intravitally or in vitro has been previously shown to be a reliable method to enumerate pancreatic islets without altering their secretory capacity (21, 23). This simple and rapid procedure allowed the simultaneous measurement of insulin stores and islet mass from the same animals. We show here an increase of 2- to 3-fold in pancreatic insulin content during pregnancy in 4-month-old control females, somewhat lower than the 6-fold increase shown in another study with younger females (30). In addition, we confirm a 2-fold increase of the endocrine pancreatic mass, normally occurring during pregnancy (20, 21). In control animals, the data showing a shift toward larger islets together with the similar number of islets per cm² sustain the previous observations of Parsons et al. (21) using a similar staining procedure and favor the hypothesis of increased islet cell proliferation rather than islet neogenesis as a mechanism for the expansion of the islet mass during pregnancy. However, the contribution of islet neogenesis cannot be ruled out because it cannot be excluded that very small islets could remain undetectable with dithizone staining. Indeed, an extensive morphometric study of insulin-positive cells during normal and experimental diabetic pregnancies has recently shown a significant increase in the number of very small islets, indicating that islet neogenesis could contribute for a small part to the increased ß-cell mass during pregnancy (31).

The increased demand of pregnancy at 4 months of age did not precipitate previously malnourished females in gestational diabetes and the increase of insulin contents and islet mass suggests that the endocrine adaptation to pregnancy occurred quite normally. Eight-month-old control animals show no sustained increase in insulin content at day 20.5 of pregnancy, despite a significant increase in islet mass, although less important than at 4 months. This apparent discrepancy might reflect that to meet the increased need for insulin, a higher fraction of insulin stores is used for purposes of secretion at 8 months than at 4 months, suggesting a poor compensatory insulin synthesis at that age. Such a decrease in insulin synthesis and storage late in pregnancy in older animals could also hold true in previously malnourished females. In those animals, the combined effects of age and pregnancy induced a total blunting of the adaptation of the endocrine pancreas to pregnancy, which was demonstrated both with insulin content and islet mass measurements.

The precise mechanisms underlying the blunted increase of islet mass during pregnancy in older previously malnourished females have not been addressed in the present study and deserve further investigation. Several hypothesis can be raised: a general decrease in the basal ß-cell proliferative rate, a reduced number of cells able to respond to lactogenic stimuli or decreased number of lactogenic receptors on the ß cells. Also, an insufficient release of these hormonal stimuli or an impairment in their signalling pathway could be suspected. The shift of islet size distribution toward larger islets at the detriment of smaller islets together with the increase in mean islet size observed during pregnancy may suggest that islet cell proliferation occurs in these animals. Alternatively, ß-cell hypertrophy could also explain such a finding. The precise answers to these questions deserve further investigation. Furthermore, the finding of decreased number of islets/cm² in pregnant 8-month-old previously malnourished females, compared with pregnant control animals, raises another issue. It is possible that increased cell death that could not be compensated for by the ß-cell proliferative rate could occur in these animals. Indeed, an increased rate of apoptosing ß cells has been described in normal rat pancreas shortly after delivery (29). This normal process contributing to the remodeling of the endocrine pancreas could start at an earlier stage in females that have been malnourished during their perinatal life.

The question as to whether the long-lasting impairment observed in the present study originates in utero remains open. It seems reasonable to assume that all islets originate by budding from the ductal epithelium. Using human GH-expressing transgenic mice, Parsons et al. (21) have observed that some animals had far greater number of small islets than the nontransgenic controls and suggested that it might happen to those animals exposed in vivo to higher lactogenic stimuli. This suggests that chronic stimulation with lactogenic hormones in utero could also contribute to the formation of new small islets by recruiting more progenitor cells in the ductal epithelium (21). The offspring born from food-restricted mothers have fewer ß cells at birth, and we have shown it was likely to be the result of decreased islet neogenesis (3). It is worth considering that those fetuses whose mothers were food-restricted during the last third of pregnancy received less lactogenic stimulation, which could be partly responsible, together with other factors, for the decreased formation of new islets.

In conclusion, early malnutrition has dramatic consequences on the capacity of the endocrine pancreas to meet the increased insulin demand of pregnancy in older animals and raises the question of the fetal outcome. This notion could be important to take into account in late human pregnancies when the mother is born with severe intrauterine growth retardation.

	Footnotes

 
¹ This work was funded by the Institut National de la Santé et de la Recherche Médicale (INSERM) and a grant of the Fondation pour la Recherche Médicale.

² Doctoral recipient of Ministère de l’Education Nationale, de l’Enseignement Supérieur et de la Recherche.

³ We thank Novo Laboratories for financial support to A. Garofano.

Received December 11, 1998.

	References

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1. Gluckman P, Harding J 1992 The regulation of fetal growth. In: Hernandez M, Argente J (eds) Human Growth Basic and Clinical Aspects. Elsevier Science, Amsterdam, pp 253–286
2. Owens J 1991 Endocrine and substrate control of fetal growth: placental and maternal influences and insulin-like growth factors. Reprod Fertil Dev 3:501–517[CrossRef][Medline]
3. Garofano A, Czernichow P, Bréant B 1997 In utero undernutrition impairs rat ß-cell development. Diabetologia 40:1231–1234[CrossRef][Medline]
4. Snoeck A, Remacle C, Reusens B, Hoet J 1990 Effect of a low protein diet during pregnancy on the fetal rat endocrine pancreas. Biol Neonate 57:107–118[Medline]
5. Garofano A, Czernichow P, Bréant B 1998 ß-cell mass and proliferation following late fetal and early postnatal malnutrition in the rat. Diabetologia 41:1114–1120[CrossRef][Medline]
6. Lithell H, McKeigue P, Berglund L, Mohsen R, Lithell U, Leon D 1996 Relation of size at birth to non-insulin dependent diabetes and insulin concentrations in men aged 50–60 years. Br Med J 312:406–410[Abstract/Free Full Text]
7. Phipps K, Barker D, Hales C, Fall C, Osmond C, Clark P 1993 Fetal growth and impaired glucose tolerance in men and women. Diabetologia 36:225–228[CrossRef][Medline]
8. Hales C, Barker D, Clark P, Cox L, Fall C, Osmond C, Winter P 1991 Fetal and infant growth and impaired glucose tolerance at age 64. Br Med J 303:1019–1022
9. Barker D, Hales C, Fall C, Osmond C, Phipps K, Clark P 1993 Type 2 (non-insulin-dependent) diabetes mellitus, hypertension and hyperlipidemia (syndrome X): relation to reduced fetal growth. Diabetologia 36:62–67[CrossRef][Medline]
10. Hales C, Barker D 1992 Type 2 (non-insulin-dependent) diabetes mellitus: the thrifty phenotype hypothesis. Diabetologia 35:595–601[CrossRef][Medline]
11. Holness M, Sugden M 1996 Suboptimal protein nutrition in early life later influences insulin action in pregnant rats. Diabetologia 39:12–21[Medline]
12. Wilson M, Hughes S 1997 The effect of maternal protein deficiency during pregnancy and lactation on glucose tolerance and pancreatic function in adult rat offspring. J Endocrinol 154:177–185[Abstract]
13. Parsons JA, Brelje TC, Sorenson RL 1992 Adaptation of islets of Langerhans to pregnancy: increased islet cell proliferation and insulin secretion correlates with the onset of placental lactogen secretion. Endocrinology 130:1459–1466[Abstract]
14. Bone A, Taylor K 1976 Metabolic adaptation to pregnancy shown by increased biosynthesis of insulin in islets of Langerhans isolated from pregnant rats. Nature 262:501–502[CrossRef][Medline]
15. Kawai M, Kishi K 1997 In vitro studies of the stimulation of insulin secretion and B-cell proliferation by rat placental lactogen-II during pregnany in rats. J Reprod Fertil 109:145–152[Abstract]
16. Nieuwenhuizen A, Schuiling G, Moes H, Koiter T 1997 Role of increased insulin demand in the adaptation of the endocrine pancreas to pregnancy. Acta Physiol Scand 159:303–312[CrossRef][Medline]
17. Sorenson R, Brelje T, Roth C 1993 Effects of steroid and lactogenic hormones on islets of Langerhans: a new hypothesis for the role of pregnancy steroids in the adaptation of islets to pregnancy. Endocrinology 133:2227–2234[Abstract]
18. Brelje T, Sorenson R 1991 Role of prolactin versus growth hormone on islet B-cell proliferation in vitro: implications for pregnancy. Endocrinology 128:45–57[Abstract]
19. Brelje T, Scharp D, Lacy P, Ogren L, Talamantes F, Robertson M, Friesen H, Sorenson R 1993 Effect of homologous placental lactogens, prolactins, and growth hormones on islet ß-cell division and insulin secretion in rat, mouse and human islets: implication for placental lactogen regulation of islet function during pregnancy. Endocrinology 132:879–887[Abstract]
20. Marynissen G, Aerts L, Assche FV 1983 The endocrine pancreas during pregnancy and lactation. J Dev Physiol 5:373–381[Medline]
21. Parsons J, Bartke A, Sorenson R 1995 Number and size of islets of Langerhans in pregnant, human growth hormone-expressing transgenic, and pituitary dwarf mice: effect of lactogenic hormones. Endocrinology 136:2013–2021[Abstract]
22. Garofano A, Czernichow P, Bréant B 1998 Postnatal somatic growth and insulin contents in moderate or severe intra-uterine growth retardation. Biol Neonate 73:89–98[CrossRef][Medline]
23. Bonnevie-Nielsen V, Skovgaard L, Lernmark A 1983 ß-cell function relative to islet volume and hormone content in the isolated perfused mouse pancreas. Endocrinology 112:1049–1056[Abstract]
24. Latif Z, Noel J, Alejandro R 1988 A simple method of staining fresh and cultured islets. Transplantation 45:827–830[Medline]
25. Reaven E, Wright D, Mondon C, Solomon R, Ro H, Reaven G 1983 Effect of age and diet on insulin secretion and insulin action in the rat. Diabetes 32:175–180[Abstract]
26. Wang S, Halban P, Rowe J 1988 Effect of aging on insulin synthesis and secretion. Differential effects on preproinsulin messenger RNA levels, proinsulin biosynthesis, and secretion of newly made and performed insulin in the rat. J Clin Invest 81:176–184
27. DeFronzo R 1979 Glucose intolerance and aging. Evidence for tissue insensitivity to insulin. Diabetes 28:1095–1101[Medline]
28. Chen M, Bergman R, Porte D 1988 Insulin resistance and ß-cell dysfunction in aging: the importance of dietary carbohydrate. J Clin Endocrinol Metab 67:951–957[Abstract]
29. Scaglia L, Smith F, Bonner-Weir S 1995 Apoptosis contributes to the involution of ß-cell mass in the post-partum rat pancreas. Endocrinology 136:5461–5468[Abstract]
30. Munoz C, Lopez-Luna P, Herrera E 1995 Glucose and insulin tolerance tests in the rat on different days of gestation. Biol Neonate 68:282–291[Medline]
31. Aerts L, Vercruysse L, Assche FV 1997 The endocrine pancreas in virgin and pregnant offspring of diabetic pregnant rats. Diabetes Res Clin Pract 38:9–19[CrossRef][Medline]

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