The action of cyclosporin A on the endocrine pancreas in vitro--functional and morphological studies.
We investigated the effect of Cyclosporin A (100 ng/ml - 12000 ng/ml) on functional parameters of the endocrine pancreas in vitro. The insulin secretion of isolated islets in response to a variety of secretory stimulators is characterized by minimal alteration occasionally observed in the presence of very high Cyclosporin A concentrations. Cyclosporin A did not alter the glucose-induced biphasic insulin secretion, nor the arginine-stimulated glucagon secretion of the perfused rat pancreas. Exposure of isolated islets to 2000 ng Cyclosporin A/ml for 3 weeks resulted in a minimal decrease of insulin content and a marked reduction of glucagon content, which were not accompanied by drastic alterations of insulin secretion. Scanning electron micrographs of these Cyclosporin A-treated islets did not differ from cultured control islets. The results let us assume that Cyclosporin A exerts no toxic effects on the endocrine pancreas in vitro, when exposed to concentrations greater than or equal to 2000 ng/ml.
D000818:Animals; D001120:Arginine / Q000494:pharmacology; D003524:Cyclosporins / Q000494:pharmacology*; D005260:Female; D005934:Glucagon / Q000378:metabolism; D005947:Glucose / Q000494:pharmacology; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning; D051381:Rats; D011919:Rats, Inbred Strains
D003524:Cyclosporins; D007328:Insulin; D005934:Glucagon; D001120:Arginine; D005947:Glucose