title: Human parathyroid adenoma adenylate cyclase: stimulation by histamine that is blocked by cimetidine.
abstract: Recent evidence suggests that the histamine receptor blocking agent cimetidine can decrease parathyroid hormone release from human parathyroids. To determine the mechanism for inhibition we examined the ability of histamine 1 X 10(-5) moles/liter to stimulate adenylate cyclase in a particulate membrane preparation from 13 human parathyroid glands. Histamine significantly increased adenylate cyclase activity as compared to control; however, the degree of stimulation was variable among the individual tissue samples. Enzyme stimulation was dose dependent over the concentration range of 1 X 10(-7) to 1 X 10(-4) moles/liter. Cimetidine at 1 X 10(-4) moles/liter completely abolished the histamine mediated increase in activity, but did not block the epinephrine-induced stimulation. The identification of an adenylate cyclase system in certain human parathyroid adenomas that is stimulated by histamine and blocked by cimetidine may offer a basis for the pharmacologic alteration of parathyroid hormone secretion.
mesh_terms: D000236:Adenoma / Q000201:enzymology*; D000067956:Adenylyl Cyclase Inhibitors; D000262:Adenylyl Cyclases / Q000378:metabolism*; D002927:Cimetidine / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects; D004837:Epinephrine / Q000494:pharmacology; D006146:Guanidines / Q000494:pharmacology*; D006165:Guanylyl Imidodiphosphate / Q000494:pharmacology; D006632:Histamine / Q000494:pharmacology*; D006801:Humans; D010282:Parathyroid Neoplasms / Q000201:enzymology*; D012969:Sodium Fluoride / Q000494:pharmacology
chemical_list: D000067956:Adenylyl Cyclase Inhibitors; D006146:Guanidines; D006165:Guanylyl Imidodiphosphate; D002927:Cimetidine; D006632:Histamine; D012969:Sodium Fluoride; D000262:Adenylyl Cyclases; D004837:Epinephrine