This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by MURPHY, L. J. Articles by REID, R. E. Search for Related Content PubMed PubMed Citation Articles by MURPHY, L. J. Articles by REID, R. E.

Enhanced Expression of Insulin-Like Growth Factor-Binding Protein-I in the Fasted Rat: The Effects of Insulin and Growth Hormone Administration^*

LIAM J. MURPHY, CHARITA SENEVIRATNE, PAUL MOREIRA and RONALD E. REID

Departments of Internal Medicine and Physiology, Faculty of Medicine, and Faculty of Pharmacy (R.E.R.), University of Manitoba Winnipeg, Manitoba, Canada R3E OW3

Abstract

The effect of fasting on insulin-like growth factor- binding protein-1 (IGFBP-1) expression was examined in the rat. Food deprivation for a period of 24 h resulted in a 9.5 ± 2.0-fold increase in hepatic IGFBP-1 mRNA abundance (P < 0.001). An increase in circulating IGFBP-1 in sera from fasted rats was demonstrated by immunoblotting, and an increased abundance of a 30-kDa IGFBP in sera from fasted rats was apparent when [125I]IGF-I was used in ligand blotting experiments. Refeeding resulted in a prompt decline in hepatic IGFBP- 1 mRNA. Administration of insulin (0.5-4 U, ip) to fasted rats resulted in profound hypoglycemia, but either increased or had no significant effect on hepatic IGFBP-1 mRNA abundance. In contrast, administration of human GH (hGH; 100 µg, ip) resulted in a prompt decline in hepatic IGFBP-1 mRNA, followed by a late rebound in IGFBP-1 mRNA to levels greater than those in fasted controls. Furthermore, hepatic IGFBP-1 mRNA levels were significantly lower in hGH-treated (100 µg every 8 h) fooddeprived rats than in saline-treated food-deprived rats (2.25 ± 1.55- vs. 8.99 ± 3.80-fold increase; P < 0.005). Similar changes were observed when serum IGFBP-1 was quantitated by immunoblotting. The effects of GH could not be explained by secondary hyperinsulinism, since no significant increase in insulin levels was observed in GH-treated rats. From these observations we conclude the enhanced expression of IGFBP-1 in the fooddeprived rat may be a consequence of GH deficiency rather than insulin deficiency. (Endocrinology 128: 689–696, 1991)

Footnotes

^* This work was supported by grants from the Medical Research Council and the Canadian Diabetes Association.

Recipient of a Medical Research Council scholarship award.

Received July 26, 1990.

This article has been cited by other articles:

				G. Gat-Yablonski, T. Ben-Ari, B. Shtaif, O. Potievsky, O. Moran, R. Eshet, G. Maor, Y. Segev, and M. Phillip Leptin Reverses the Inhibitory Effect of Caloric Restriction on Longitudinal Growth Endocrinology, January 1, 2004; 145(1): 343 - 350. [Abstract] [Full Text] [PDF]

				H. Norrelund, J. Frystyk, J. O. L. Jorgensen, N. Moller, J. S. Christiansen, H. Orskov, and A. Flyvbjerg The Effect of Growth Hormone on the Insulin-Like Growth Factor System during Fasting J. Clin. Endocrinol. Metab., July 1, 2003; 88(7): 3292 - 3298. [Abstract] [Full Text] [PDF]

				W. M. Naranjo, S. Yakar, M. Sanchez-Gomez, A. U. Perez, J. Setser, and D. LERoith Protein Calorie Restriction Affects Nonhepatic IGF-I Production and the Lymphoid System: Studies Using the Liver-Specific IGF-I Gene-Deleted Mouse Model Endocrinology, June 1, 2002; 143(6): 2233 - 2241. [Abstract] [Full Text] [PDF]

				J. Frystyk, P. J. D. Delhanty, C. Skjarbak, and R. C. Baxter Changes in the circulating IGF system during short-term fasting and refeeding in rats Am J Physiol Endocrinol Metab, August 1, 1999; 277(2): E245 - E252. [Abstract] [Full Text] [PDF]

				G. Schweizer-Groyer, N. Jibard, E. Neau, D. Fortin, F. Cadepond, E.-E. Baulieu, and A. Groyer The Glucocorticoid Response Element II Is Functionally Homologous in Rat and Human Insulin-like Growth Factor-binding Protein-1 Promoters J. Biol. Chem., April 23, 1999; 274(17): 11679 - 11686. [Abstract] [Full Text] [PDF]

				J. Zhang, D. Chrysis, and L. E. Underwood Reduction of Hepatic Insulin-Like Growth Factor I (IGF-I) Messenger Ribonucleic Acid (mRNA) during Fasting Is Associated with Diminished Splicing of IGF-I Pre-mRNA and Decreased Stability of Cytoplasmic IGF-I mRNA Endocrinology, November 1, 1998; 139(11): 4523 - 4530. [Abstract] [Full Text] [PDF]