Methylamine and islet function: possible relationship to Ca2+-sensitive transglutaminase.
Pancreatic islet homogenates display Ca2+-dependent transglutaminase activity. Methylamine inhibits the enzyme activity, accumulates in intact islet cells, is incorporated in endogenous islet proteins, and inhibits glucose-stimulated insulin release. The inhibition by methylamine of both enzyme activity and insulin release is inversely related to the ambient Ca2+ concentration. Dimethylamine also inhibits transglutaminase activity and glucose-stimulated insulin release. However, trimethylamine, which does not affect transglutaminase activity, again inhibits glucose-stimulated insulin release, the latter inhibition being also inversely related to the Ca2+ concentration. It is concluded that the impairment of insulin release by methylamines is not necessarily linked to inhibition of transglutaminase activity.
D000217:Acyltransferases / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002364:Caseins / Q000378:metabolism; D004123:Dimethylamines / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D006632:Histamine / Q000378:metabolism; D007328:Insulin / Q000378:metabolism; D007515:Islets of Langerhans / Q000187:drug effects* / Q000201:enzymology; D007700:Kinetics; D008744:Methylamines / Q000494:pharmacology*; D011700:Putrescine / Q000378:metabolism; D051381:Rats; D011503:Transglutaminases
D002364:Caseins; D004123:Dimethylamines; D007328:Insulin; D008744:Methylamines; C002087:N,N-dimethylcasein; D006632:Histamine; C034516:dimethylamine; C027451:methylamine; D000217:Acyltransferases; D011503:Transglutaminases; C023336:trimethylamine; D002118:Calcium; D011700:Putrescine