title: Long-term regulation of catecholamine formation by ouabain in cultured bovine adrenal chromaffin cells.
abstract: The long-term effects of ouabain, an inhibitor of Na+/K+ -ATPase, on catecholamine formation in cultured bovine adrenal chromaffin cells were examined. The increase in [14C]catecholamine formation from [14C]tyrosine induced by ouabain was dependent on incubation time, and its maximal effect was observed after incubation for 8 h. The stimulatory effect of ouabain was concentration dependent (10-300 nM), causing maximal stimulation at 300 nM. The formation of [14C]catecholamines induced by ouabain was not increased by incubation with [14C]DOPA instead of [14C]tyrosine. Ouabain-induced [14C]catecholamine formation was influenced by decreases in extracellular Ca2+ concentration, but not by the presence of cycloheximide or actinomycin D. These results suggested that ouabain stimulates continuous activation of hydroxylation of tyrosine through a Ca2+ -dependent mechanism in cultured bovine adrenal chromaffin cells.
authors.affiliation: Department of Pharmacy, Tokushima University Hospital, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Ozawa
authors.forename: H
authors.initials: H
authors.lastname: Houchi
authors.forename: K
authors.initials: K
authors.lastname: Teraoka
authors.forename: M
authors.initials: M
authors.lastname: Azuma
authors.forename: T
authors.initials: T
authors.lastname: Kamimura
authors.forename: M
authors.initials: M
authors.lastname: Yoshizumi
authors.forename: K
authors.initials: K
authors.lastname: Tsuchiya
authors.forename: T
authors.initials: T
authors.lastname: Tamaki
authors.forename: K
authors.initials: K
authors.lastname: Minakuchi
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D002395:Catecholamines / Q000096:biosynthesis*; D002417:Cattle; D002478:Cells, Cultured; D019439:Chromaffin Cells / Q000187:drug effects* / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D010042:Ouabain / Q000494:pharmacology*; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors*; D014443:Tyrosine / Q000378:metabolism; D014446:Tyrosine 3-Monooxygenase / Q000502:physiology
chemical_list: D002395:Catecholamines; D004791:Enzyme Inhibitors; D014443:Tyrosine; D010042:Ouabain; D014446:Tyrosine 3-Monooxygenase; D000254:Sodium-Potassium-Exchanging ATPase; D002118:Calcium