Effects of protease inhibitors and calmodulin inhibitors on Ca2+ influx and catecholamine secretion in isolated bovine adrenal medullary cells.
Acetylcholine (ACh) (10(-4) M) induced Ca2+ influx (21.2 nmol/mg cell protein/3 min) and catecholamine (CA) secretion (11.5% of total CA content) in isolated bovine adrenal medullary cells. Both excess K+ (56 mM KCl) and a calcium ionophore (A-23187: 10(-5) M) also induced CA secretion (9.7 and 7.5%, respectively, of total CA content). Protease inhibitors [gabexate mesilate (FOY), TLCK], a synthetic substrate of protease (TAME) and calmodulin inhibitors (W-7, trifluoperazine, promethazine, chlorpromazine) inhibited Ca2+ influx and CA secretion induced by ACh. Protease inhibitors and a substrate of protease had no effect on CA secretion induced by excess K+, and a high concentration of calmodulin inhibitors was required to inhibit excess K+-induced CA secretion. CA secretion induced by A-23187 was not inhibited by these inhibitors and the substrate.
D000313:Adrenal Medulla / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002147:Calmodulin / Q000037:antagonists & inhibitors*; D002395:Catecholamines / Q000378:metabolism*; D002417:Cattle; D002746:Chlorpromazine / Q000494:pharmacology; D016670:Gabexate; D006146:Guanidines / Q000494:pharmacology; D066298:In Vitro Techniques; D011398:Promethazine / Q000494:pharmacology; D011480:Protease Inhibitors / Q000494:pharmacology*; D013449:Sulfonamides / Q000494:pharmacology; D014106:Tosylarginine Methyl Ester / Q000494:pharmacology; D014107:Tosyllysine Chloromethyl Ketone / Q000494:pharmacology; D014268:Trifluoperazine / Q000494:pharmacology
D002147:Calmodulin; D002395:Catecholamines; D006146:Guanidines; D011480:Protease Inhibitors; D013449:Sulfonamides; D014107:Tosyllysine Chloromethyl Ketone; D014268:Trifluoperazine; D016670:Gabexate; C017967:W 7; D014106:Tosylarginine Methyl Ester; D011398:Promethazine; D002118:Calcium; D002746:Chlorpromazine