Abstract
Isolated rat pancreatic islets were preincubated in a medium with 16.7mM glucose and incubated with 5.5mM glucose. Both histamine (100μ M) and neurotensin (100nM) stimulated glucagon release from the isolated islets, but not insulin release. The stimulation of glucagon release occurred in the presence of 10 and 100nM neurotensin, while the release of insulin was inhibited in the presence of 1 and 10nM neurotensin. The neurotensin-induced glucagon release was completely inhibited by 1mM metiamide, an histamine H2-receptor antagonist, added to the incubation medium and not inhibited by 1mM diphenhydramine, an histamine H1-receptor antagonist.
The results indicate that the histaminergic mechanism, including the H2-receptor system, may be involved in neurotensin-induced glucagon release from the endocrine pancreas.
