title: Dihydropyridine calcium agonist and antagonist effects on aldosterone secretion.
abstract: The effects of the dihydropyridine calcium antagonists nimodipine, nitrendipine, and nisoldipine were studied on K+-induced and angiotensin II (ANG II)-induced aldosterone secretion from isolated calf adrenal glomerulosa cells. These drugs were more effective inhibitors of K+-induced secretion than ANG II-induced secretion. However, when the ANG II-induced release of intracellular calcium was blocked by prior treatment of cells with dantrolene, then nitrendipine was equally as effective in blocking ANG II- as K+-induced secretion. On the other hand, the dihydropyridine agonist, BAY K8644, was found to enhance K+-induced secretion to a greater extent than ANG II-induced secretion when the latter was studied in either the absence or presence of dantrolene. It is concluded that K+ and ANG II mobilize calcium from different sources for stimulus-response coupling in these cells and that there is no difference in the sensitivity to nitrendipine of the plasma membrane calcium channels operated by these two different agonists.
mesh_terms: D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; D000311:Adrenal Glands / Q000166:cytology; D000450:Aldosterone / Q000378:metabolism*; D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D002417:Cattle; D002478:Cells, Cultured; D003620:Dantrolene / Q000494:pharmacology; D007473:Ion Channels / Q000187:drug effects*; D009539:Nicotinic Acids / Q000494:pharmacology; D009543:Nifedipine / Q000031:analogs & derivatives / Q000494:pharmacology; D009553:Nimodipine; D015737:Nisoldipine; D009568:Nitrendipine; D011188:Potassium / Q000494:pharmacology; D013268:Stimulation, Chemical
chemical_list: D002121:Calcium Channel Blockers; D007473:Ion Channels; D009539:Nicotinic Acids; D000804:Angiotensin II; D000450:Aldosterone; D015737:Nisoldipine; D009553:Nimodipine; D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; D009568:Nitrendipine; D003620:Dantrolene; D009543:Nifedipine; D011188:Potassium; D002118:Calcium