Tolbutamide-induced changes of the DNA, protein and insulin content and the secretory activity of isolated rat pancreatic islets.
Following prolonged administration of tolbutamide the DNA- and protein content per islet was enhanced but the IRI content per islet was diminished. Glucose-induced (2.0, 8.0 or 16.6 mM) and leucine-induced (12.5 or 25.0 mM) IRI release from isolated islets, as well as 14C02-production from U-14C glucose, were decreased. Theophylline (5.0 mM) restored the glucose sensitivity of the islets towards normal. The results indicate that tolbutamide-induced islet cell hyperplasia does not entail islet hyperfunction, as previously thought. Decreased IRI release may partially be explained by a tolbutamide-induced alteration of the adenylate cyclase/phosphodiesterase system of the B-cell.
D000818:Animals; D004247:DNA / Q000378:metabolism*; D005947:Glucose / Q000494:pharmacology; D006965:Hyperplasia; D066298:In Vitro Techniques; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000187:drug effects* / Q000378:metabolism; D007930:Leucine / Q000494:pharmacology; D008297:Male; D011506:Proteins / Q000378:metabolism*; D051381:Rats; D013806:Theophylline / Q000494:pharmacology; D014044:Tolbutamide / Q000037:antagonists & inhibitors / Q000494:pharmacology*
D007328:Insulin; D011506:Proteins; D004247:DNA; D014044:Tolbutamide; D013806:Theophylline; D007930:Leucine; D005947:Glucose