Mechanisms of sulfonylurea-induced insulin release.
The mechanisms responsible for the stimulation of insulin release from the pancreatic beta-cell by hypoglycemic sulfonylureas are reviewed herein. One hypothesis postulates that these agents act, at the level of the plasma membrane, by causing the closure of a class of K+ channels characterized by their sensitivity to ATP. This may lead to depolarization of the plasma membrane, gating of voltage-sensitive Ca2+ channels, increase in cytosolic Ca2+ activity, and activation of the effector system for insulin release. However, it is not evident that the closure of ATP-sensitive K+ channels accounts for effects of sulfonylureas such as inhibition of K+ inflow into the islet cells, increase in their Na+ content, or even stimulation of Ca2+ inflow and insulin release at physiological or higher concentrations of D-glucose.
Laboratory of Experimental Medicine, Brussels Free University, Belgium.
W J
WJ
Malaisse
P
P
Lebrun
D006801:Humans; D007328:Insulin / Q000378:metabolism*; D010179:Pancreas / Q000378:metabolism; D013453:Sulfonylurea Compounds / Q000494:pharmacology*
D007328:Insulin; D013453:Sulfonylurea Compounds