Calcium-dependence of serotonin-mediated aldosterone secretion and differential effects of calcium antagonists.
The requirement for calcium in the serotonin-mediated aldosterone secretion was investigated using rat adrenal capsular cells. In the calcium-free medium both basal as well as serotonin-stimulated aldosterone secretion (at concentrations of 10(-7) M and 10(-8) M of serotonin) were significantly impaired. The effects of calcium-channel blockers were then examined. Verapamil (10(-5) M and 10(-6) M markedly inhibited basal and serotonin-evoked aldosterone secretion. In equimolar concentrations nifedipine had much less effect and diltiazem produced no apparent attenuation of either basal or serotonin-stimulated aldosterone secretion. These results indicate the calcium-dependence of serotonin-induced aldosterone secretion. The variable effects of the calcium-channel blockers suggest different or multiple mechanisms of action of these agents.
D000302:Adrenal Cortex / Q000187:drug effects / Q000378:metabolism*; D000450:Aldosterone / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000502:physiology*; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D004110:Diltiazem / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D009543:Nifedipine / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000502:physiology*; D014700:Verapamil / Q000494:pharmacology
D002121:Calcium Channel Blockers; D012701:Serotonin; D000450:Aldosterone; D014700:Verapamil; D004110:Diltiazem; D009543:Nifedipine; D002118:Calcium