AJP - Gastrointestinal and Liver Physiology, Vol 266, Issue 5 887-G891, Copyright © 1994 by American Physiological Society

ARTICLES

Regulation of glucose-dependent insulinotropic peptide gene expression by a glucose meal

C. C. Tseng, L. A. Jarboe and M. M. Wolfe
Harvard Digestive Disease Center, Division of Gastroenterology, Harvard Medical School, Boston, Massachusetts.

Glucose-dependent insulinotropic peptide (GIP) enhances insulin secretion by pancreatic beta-islet cells. Its release has been demonstrated predominantly after the ingestion of carbohydrate and fat. We have recently cloned a rat intestinal GIP cDNA and in the present studies have used this cDNA as a probe for measuring rat duodenal GIP mRNA after nutrient administration. Rats were fasted overnight, after which they were permitted to drink water or 10% glucose. The duodenum was then removed, GIP mRNA was measured by Northern hybridization analysis, and duodenal mucosa and serum GIP levels were determined by radioimmunoassay. In response to oral 10% glucose, duodenal mucosal GIP mRNA concentrations increased from 2 to 4 h, and at the end of 4 h a threefold increase was detected. Serum and mucosal GIP concentrations increased earlier, starting at 60 min, and levels remained elevated at 4 h. In separate studies, nuclear run-on assays were performed to compare the effects of glucose and water ingestion on transcription of the GIP gene. Whereas no increase in GIP gene transcription was detected in rats ingesting water, the rate of transcription doubled in glucose-fed rats. Actin gene transcription was nearly identical in both groups, indicating genomic specificity. The results of these studies indicate that duodenal GIP gene expression is stimulated at both the pre- and posttranslational levels by glucose-containing meals. These studies further suggest that the release of GIP from cellular storage granules might account for the initial increase in serum GIP levels after oral glucose ingestion.

This article has been cited by other articles:

				S. Y. Wang, M. M.-Y. Chi, L. Li, K. H. Moley, and B. M. Wice Studies with GIP/Ins cells indicate secretion by gut K cells is KATP channel independent Am J Physiol Endocrinol Metab, May 1, 2003; 284(5): E988 - E1000. [Abstract] [Full Text] [PDF]

				J.-C. Gevrey, M. Cordier-Bussat, E. Nemoz-Gaillard, J.-A. Chayvialle, and J. Abello Co-requirement of Cyclic AMP- and Calcium-dependent Protein Kinases for Transcriptional Activation of Cholecystokinin Gene by Protein Hydrolysates J. Biol. Chem., June 14, 2002; 277(25): 22407 - 22413. [Abstract] [Full Text] [PDF]

				A. T. Cheung, B. Dayanandan, J. T. Lewis, G. S. Korbutt, R. V. Rajotte, M. Bryer-Ash, M. O. Boylan, M. M. Wolfe, and T. J. Kieffer Glucose-Dependent Insulin Release from Genetically Engineered K Cells Science, December 8, 2000; 290(5498): 1959 - 1962. [Abstract] [Full Text]

				J.-L. Shie, Z. Y. Chen, M. J. O'Brien, R. G. Pestell, M.-E. Lee, and C.-C. Tseng Role of gut-enriched Kruppel-like factor in colonic cell growth and differentiation Am J Physiol Gastrointest Liver Physiol, October 1, 2000; 279(4): G806 - G814. [Abstract] [Full Text] [PDF]

				M. M. Wolfe, K.-B. Zhao, K. D. Glazier, L. A. Jarboe, and C.-C. Tseng Regulation of glucose-dependent insulinotropic polypeptide release by protein in the rat Am J Physiol Gastrointest Liver Physiol, September 1, 2000; 279(3): G561 - G566. [Abstract] [Full Text] [PDF]

				M. O. Boylan, L. I. Jepeal, L. A. Jarboe, and M. M. Wolfe Cell-specific Expression of the Glucose-dependent Insulinotropic Polypeptide Gene in a Mouse Neuroendocrine Tumor Cell Line J. Biol. Chem., July 11, 1997; 272(28): 17438 - 17443. [Abstract] [Full Text] [PDF]