Differences in insulin secretion between the rat and mouse: role of cAMP

Metabolic Research Unit, University of California, San Francisco 94143.

Although information regarding insulin secretion usually is considered equivalent when generated in the mouse or the rat, it is established that the kinetics of insulin secretion from mouse and rat pancreatic beta cells differ. The mechanisms underlining these differences are not understood. The in vitro perfused pancreas and isolated islets of the mouse or rat were employed in this study to investigate the role of cyclic adenosine monophosphate (cAMP), a major positive modulator of beta-cell function, as one differentiating signal for the uniquely different insulin release from the beta cells of these commonly used rodents. Glucose-stimulated first-phase insulin release from the perfused pancreas of the rat was higher than the mouse when calculated per gram of pancreas or as fractional secretion, but this phase was identical in the two species when results were adjusted for total body weight. Whether related to insulin content, pancreatic weight or body weight, the rat pancreas responded to glucose with a progressively increasing second-phase insulin release compared to the mouse pancreas, which secreted a flat second-phase of lesser magnitude. Isolated islets from rat and mouse were comparable in insulin content whereas the basal cAMP level of mouse islets was less than half that of the rat. At submaximal stimulation with glucose or glucose + IBMX or forskolin, mouse islets exhibited lower cAMP levels to a given stimulus than the rat. In rat islets cAMP levels increased to approximately 1000 fmol per islet, although insulin secretion maximized by 100-150 fmol.(ABSTRACT TRUNCATED AT 250 WORDS)

This article has been cited by other articles:

				C. S. Nunemaker, D. H. Wasserman, O. P. McGuinness, I. R. Sweet, J. C. Teague, and L. S. Satin Insulin secretion in the conscious mouse is biphasic and pulsatile Am J Physiol Endocrinol Metab, March 1, 2006; 290(3): E523 - E529. [Abstract] [Full Text] [PDF]

				J.-C. Henquin, M. Nenquin, P. Stiernet, and B. Ahren In Vivo and In Vitro Glucose-Induced Biphasic Insulin Secretion in the Mouse: Pattern and Role of Cytoplasmic Ca2+ and Amplification Signals in {beta}-Cells Diabetes, February 1, 2006; 55(2): 441 - 451. [Abstract] [Full Text] [PDF]

				S. G. Straub, G. Shanmugam, and G. W.G. Sharp Stimulation of Insulin Release by Glucose Is Associated With an Increase in the Number of Docked Granules in the {beta}-Cells of Rat Pancreatic Islets Diabetes, December 1, 2004; 53(12): 3179 - 3183. [Abstract] [Full Text] [PDF]

				W S Zawalich, H Yamazaki, K C Zawalich, and G Cline Comparative effects of amino acids and glucose on insulin secretion from isolated rat or mouse islets J. Endocrinol., November 1, 2004; 183(2): 309 - 319. [Abstract] [Full Text] [PDF]

				J. C. Koster, M. S. Remedi, H. Qiu, C. G. Nichols, and P. W. Hruz HIV Protease Inhibitors Acutely Impair Glucose-Stimulated Insulin Release Diabetes, July 1, 2003; 52(7): 1695 - 1700. [Abstract] [Full Text] [PDF]

				M. Nakazaki, A. Crane, M. Hu, V. Seghers, S. Ullrich, L. Aguilar-Bryan, and J. Bryan cAMP-Activated Protein Kinase-Independent Potentiation of Insulin Secretion by cAMP Is Impaired in SUR1 Null Islets Diabetes, December 1, 2002; 51(12): 3440 - 3449. [Abstract] [Full Text] [PDF]

				C. Shiota, O. Larsson, K. D. Shelton, M. Shiota, A. M. Efanov, M. Hoy, J. Lindner, S. Kooptiwut, L. Juntti-Berggren, J. Gromada, et al. Sulfonylurea Receptor Type 1 Knock-out Mice Have Intact Feeding-stimulated Insulin Secretion despite Marked Impairment in Their Response to Glucose J. Biol. Chem., September 27, 2002; 277(40): 37176 - 37183. [Abstract] [Full Text] [PDF]

				J.-C. Henquin, N. Ishiyama, M. Nenquin, M. A. Ravier, and J.-C. Jonas Signals and Pools Underlying Biphasic Insulin Secretion Diabetes, February 1, 2002; 51(90001): S60 - 67. [Abstract] [Full Text] [PDF]

				P. Maechler, A. Gjinovci, and C. B. Wollheim Implication of Glutamate in the Kinetics of Insulin Secretion in Rat and Mouse Perfused Pancreas Diabetes, February 1, 2002; 51(90001): S99 - 102. [Abstract] [Full Text] [PDF]

				W. S. Zawalich, K. C. Zawalich, G. J. Tesz, J. A. Sterpka, and W. M. Philbrick Insulin secretion and IP levels in two distant lineages of the genus Mus: comparisons with rat islets Am J Physiol Endocrinol Metab, May 1, 2001; 280(5): E720 - E728. [Abstract] [Full Text] [PDF]

				W. S. Zawalich and K. C. Zawalich A Link between Insulin Resistance and Hyperinsulinemia: Inhibitors of Phosphatidylinositol 3-Kinase Augment Glucose-Induced Insulin Secretion from Islets of Lean, But Not Obese, Rats Endocrinology, September 1, 2000; 141(9): 3287 - 3295. [Abstract] [Full Text] [PDF]

				Y. Shi, J. Kanaani, V. Menard-Rose, Y. H. Ma, P.-Y. Chang, D. Hanahan, A. Tobin, G. Grodsky, and S. Baekkeskov Increased expression of GAD65 and GABA in pancreatic beta -cells impairs first-phase insulin secretion Am J Physiol Endocrinol Metab, September 1, 2000; 279(3): E684 - E694. [Abstract] [Full Text] [PDF]

				P. Rorsman, L. Eliasson, E. Renstrom, J. Gromada, S. Barg, and S. Gopel The Cell Physiology of Biphasic Insulin Secretion Physiology, April 1, 2000; 15(2): 72 - 77. [Abstract] [Full Text] [PDF]

				V. Seghers, M. Nakazaki, F. DeMayo, L. Aguilar-Bryan, and J. Bryan Sur1 Knockout Mice. A MODEL FOR KATP CHANNEL-INDEPENDENT REGULATION OF INSULIN SECRETION J. Biol. Chem., March 24, 2000; 275(13): 9270 - 9277. [Abstract] [Full Text] [PDF]

				W. S. Zawalich, M. Bonnet-Eymard, and K. C. Zawalich Glucose-induced desensitization of the pancreatic beta -cell is species dependent Am J Physiol Endocrinol Metab, December 1, 1998; 275(6): E917 - E924. [Abstract] [Full Text] [PDF]

				W. S. Zawalich, M. Bonnet-Eymard, K. C. Zawalich, and G. C. Yaney Chronic exposure to TPA depletes PKCalpha and augments Ca-dependent insulin secretion from cultured rat islets Am J Physiol Cell Physiol, May 1, 1998; 274(5): C1388 - C1396. [Abstract] [Full Text] [PDF]

				W. S. Zawalich and K. C. Zawalich Influence of Pyruvic Acid Methyl Ester on Rat Pancreatic Islets. EFFECTS ON INSULIN SECRETION, PHOSPHOINOSITIDE HYDROLYSIS, AND SENSITIZATION OF THE BETA CELL J. Biol. Chem., February 7, 1997; 272(6): 3527 - 3531. [Abstract] [Full Text] [PDF]