Article date: 2010/8/11
PubMed ID: 2026760
Journal name: Diabetes (ISSN: 1939-327X)
Together, these data suggest that insulin's inhibitory effect on alpha-cell glucagon release is in part mediated at the level of the VMH under both normoglycemic and hypoglycemic conditions.
As expected, insulin-induced hypoglycemia produced a threefold increase in plasma glucagon. However, the glucagon response was fourfold to fivefold greater when circulating insulin did not increase, despite equivalent hypoglycemia and C-peptide suppression. In contrast, epinephrine responses were not altered. The phloridzin-hypoglycemia induced glucagon increase was attenuated (40%) by VMH insulin microinjection. Conversely, local VMH blockade of insulin amplified glucagon twofold to threefold during insulin-induced hypoglycemia. Furthermore, local blockade of basal insulin levels or insulin receptors within the VMH caused an immediate twofold increase in fasting glucagon levels that was prevented by coinjection to the VMH of a GABA(A) receptor agonist.
Author List: Paranjape Sachin A, Chan Owen, Zhu Wanling, Horblitt Adam M, McNay Ewan C, Cresswell James A, Bogan Jonathan S, McCrimmon Rory J, Sherwin Robert S
Publication Types: Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't
Article Date: 2010/03/18
Substances mentioned in the article: Insulin; Glucagon; Phlorhizin; Proto-Oncogene Proteins c-akt;
Mesh terms: 3T3 Cells; Animals; Glucagon/blood; Hypoglycemia/chemically induced; Insulin/pharmacology; Insulin-Secreting Cells/secretion; Male; Mice; Pancreas/secretion; Phlorhizin/pharmacology; Proto-Oncogene Proteins c-akt/metabolism; Rats; Rats, Sprague-Dawley; Ventromedial Hypothalamic Nucleus/drug effects;
Citations: - 16567528