Ultrastructural responses of pancreatic beta cells to metabolic alkalosis.
The ultrastructural changes in pancreatic beta cells were studied following glucose-induced insulin secretion in vitro, at two different extracellular pH (7.4 and 7.8). The pancreata perfused at pH 7.4 exhibited a biphasic insulin response to glucose challenge together with signs of increased emiocytotic activity and numerous microtubules in the beta cells. Conversely, the pancreata perfused at pH 7.8 showed a significant decrease in insulin secretion, and their beta cells revealed scarce emiocytotic images and a marked increase of intracellular granulolysis. These results represent the ultrastructural correlate of the reduced insulin secretion produced by metabolic alkalosis in the perfused rat pancreas.
D000471:Alkalosis / Q000473:pathology; D000818:Animals; D005947:Glucose / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000378:metabolism / Q000648:ultrastructure*; D008870:Microtubules / Q000648:ultrastructure; D010477:Perfusion; D051381:Rats
D007328:Insulin; D005947:Glucose