To assess the effects of endogenous somatostatin on pancreatic islet A- and B-cell function, isolated rat islets were incubated in antisomatostatin γ-globulin to bind endogenously released somatostatin, and the insulin and glucagon secretion of these islets was compared with that of islets incubated in γ-globulin isolated from nonimmune serum. Islets incubated in antisomatostatin γ-globulin released significantly more insulin at 4, 8,16, and 32 mM glucose and significantly more glucagon at 8,16, and 32 mM glucose, P < 0.05–0.005. For glucose-stimulated insulin release the threshold was decreased, the Vmax was increased, but the apparent Km was unaltered; for glucose-suppression of glucagon release the threshold was increased, maximal suppression was decreased, but the apparent Ki was unaltered. The augmentative effect of the antisomatostatin γ-globulin was most prominent at 4 mM glucose for insulin release and at 8 mM glucose for glucagon release, but was not limited to glucose since both insulin and glucagon release stimulated by arginine were also augmented by antisomatostatin γ-globulin. These results provide evidence that endogenous somatostatin may act as a physiologic local regulator of both insulin and glucagon secretion and that its effect on insulin and glucagon secretion is dependent on the prevailing glucose concentration.
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Original Articles|
September 01 1980
Antisomatostatin Gamma Globulin Augments Secretion of Both Insulin and Glucagon In Vitro: Evidence for a Physiologic Role for Endogenous Somatostatin in the Regulation of Pancreatic A- and B-Cell Function
Mitsuyasu Itoh;
Mitsuyasu Itoh
Endocrine Research Unit, Departments of Medicine and Physiology, Mayo Medical School and Mayo Clinic
Rochester, Minnesota
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Lawrence Mandarino;
Lawrence Mandarino
Endocrine Research Unit, Departments of Medicine and Physiology, Mayo Medical School and Mayo Clinic
Rochester, Minnesota
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John E Gerich
John E Gerich
Endocrine Research Unit, Departments of Medicine and Physiology, Mayo Medical School and Mayo Clinic
Rochester, Minnesota
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Address reprint requests to John E. Gerich, M.D., Director, Endocrine Research Unit, Mayo Clinic, Rochester, Minnesota 55901.
Diabetes 1980;29(9):693–696
Article history
Received:
October 01 1979
Revision Received:
March 03 1980
Accepted:
March 03 1980
PubMed:
6160072
Citation
Mitsuyasu Itoh, Lawrence Mandarino, John E Gerich; Antisomatostatin Gamma Globulin Augments Secretion of Both Insulin and Glucagon In Vitro: Evidence for a Physiologic Role for Endogenous Somatostatin in the Regulation of Pancreatic A- and B-Cell Function. Diabetes 1 September 1980; 29 (9): 693–696. https://doi.org/10.2337/diab.29.9.693
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