title: Evidence for the role of calcium in the hydrosmotic response to antidiuretic hormone in frog skin.
abstract: Treatment with the calcium ionophore A23187 on either the serosal or mucosal sides of frog skin, strongly inhibits the hydrosmotic response to vasopressin. On the contrary, the hydrosmotic response to 8-br-cAMP is not affected by treatment with the A23187. Trifluoperazine, a drug which inhibits the Ca2+-calmodulin complex, selectively inhibits vasopressin-induced water transport. Collectively, our results suggest that an increase in the intracellular concentration of Ca2+, obtained by treatment with the ionophore A23187, interferes with a pre-cAMP step of the hydrosmotic response to the antidiuretic hormone. Calcium ions could regulate adenyl-cyclase activity and consequently intracellular levels of cAMP. This effect may probably involve calmodulin.
mesh_terms: D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000818:Animals; D001834:Body Water / Q000378:metabolism; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000502:physiology*; D009995:Osmosis / Q000187:drug effects; D011893:Rana esculenta / Q000502:physiology*; D012867:Skin / Q000187:drug effects*; D014268:Trifluoperazine / Q000494:pharmacology; D014667:Vasopressins / Q000494:pharmacology*
chemical_list: D014667:Vasopressins; D014268:Trifluoperazine; D015124:8-Bromo Cyclic Adenosine Monophosphate; D000001:Calcimycin; D002118:Calcium