title: Inhibitory effect of okadaic acid on carbachol-evoked secretion of catecholamines in cultured bovine adrenal medullary cells.
abstract: We examined the effect of okadaic acid on catecholamine secretion caused by carbachol in cultured bovine adrenal medullary cells. Treatment of cells with 100 nM okadaic acid for 3-24 hr produced an inhibition of catecholamine secretion stimulated by carbachol. The half-maximal and maximal inhibition of secretion was observed at 40 nM and 300 nM okadaic acid for 24 hr, respectively. Okadaic acid also inhibited veratridine- and high K(+)-induced secretion but not ionomycin-induced secretion. Okadaic acid strongly suppressed 45Ca2+ influx and slightly inhibited 22Na+ influx in carbachol-stimulated cells. These results suggest that okadaic acid inhibits carbachol-evoked secretion of catecholamines mainly by suppression of Ca2+ influx in adrenal medullary cells.
authors.affiliation: Department of Pharmacology, University of Occupational and Environmental Health, School of Medicine, Kitakyushu, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Yanagihara
authors.forename: Y
authors.initials: Y
authors.lastname: Toyohira
authors.forename: Y
authors.initials: Y
authors.lastname: Koda
authors.forename: A
authors.initials: A
authors.lastname: Wada
authors.forename: F
authors.initials: F
authors.lastname: Izumi
mesh_terms: D000313:Adrenal Medulla / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D002217:Carbachol / Q000494:pharmacology*; D002395:Catecholamines / Q000378:metabolism*; D002417:Cattle; D002478:Cells, Cultured; D004988:Ethers, Cyclic / Q000494:pharmacology*; D015759:Ionomycin / Q000494:pharmacology; D019319:Okadaic Acid; D011188:Potassium / Q000494:pharmacology; D014701:Veratridine / Q000378:metabolism
chemical_list: D002395:Catecholamines; D004988:Ethers, Cyclic; D019319:Okadaic Acid; D015759:Ionomycin; D014701:Veratridine; D002217:Carbachol; D011188:Potassium