Dihydroergotamine, but not naloxone, counteracts lithium as an inhibitor of glucose-induced insulin release in isolated rat islets in vitro.
Lithium exerts an inhibitory effect on glucose-induced insulin release. Lithium (5 mmol/l) added 30 min prior to glucose stimulation or together with glucose (16.7 mmol/l) failed to affect first phase, but reduced second phase glucose-induced insulin release by 35%. Similar results were obtained when islets isolated from rats following long-term oral lithium treatment were perifused with glucose (16.7 mmol/l). The inhibitory effect of lithium was counteracted by pretreatment of the rats with the alpha-adrenergic blocking agent dihydroergotamine, whereas the opiate antagonist naloxone had no apparent effect on lithium-induced inhibition of glucose-stimulated insulin release.
D000818:Animals; D004087:Dihydroergotamine / Q000494:pharmacology*; D005947:Glucose / Q000494:pharmacology; D007328:Insulin / Q000378:metabolism; D007329:Insulin Antagonists / Q000494:pharmacology*; D007515:Islets of Langerhans / Q000187:drug effects* / Q000378:metabolism; D008094:Lithium / Q000494:pharmacology*; D008297:Male; D009270:Naloxone / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains
D007328:Insulin; D007329:Insulin Antagonists; D009270:Naloxone; D004087:Dihydroergotamine; D008094:Lithium; D005947:Glucose