title: Histamine regulation of adenylyl cyclase of enriched rat gastric parietal cells.
abstract: Rat gastric parietal cells were isolated to 90% or greater purity by discontinuous gradient ultracentrifugation in sucrose-Ficoll. Adenylyl cyclase activity was initiated by histamine in the presence of 5'-guanylyl imidodiphosphate, but not by pentagastrin or acetylcholine. The concentration of histamine needed for half-maximal activation of adenylyl cyclase was 38 microM. The histamine H2-receptor antagonist, metiamide, inhibited histamine (100 microM) activation with a Ki of 0.9 microM. The effects of other histamine agonists and antagonists suggest that presence of H2-type histaminic receptors on parietal cells. Adenylyl cyclase activity was also stimulated by isoproterenol, norepinephrine, and epinephrine, but not by methoxamine. Half-maximal activation by isoproterenol occurred at 0.5 microM. Propranolol, but not phentolamine, prevented activation by these agents, indicating the presence of beta-adrenergic receptors on parietal cells. Prostaglandins E2 stimulated adenylyl cyclase of partially purified (30%), but not the enriched (90%), parietal cell populations.
mesh_terms: D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D005260:Female; D005753:Gastric Mucosa / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D006632:Histamine / Q000502:physiology*; D006636:Histamine Release / Q000187:drug effects; D008297:Male; D011458:Prostaglandins E / Q000494:pharmacology; D051381:Rats; D013566:Sympathomimetics / Q000494:pharmacology
chemical_list: D011458:Prostaglandins E; D013566:Sympathomimetics; D006632:Histamine; D000262:Adenylyl Cyclases