TY - JOUR T1 - Correlation of activation of Ca2+/calmodulin-dependent protein kinase II with catecholamine secretion and tyrosine hydroxylase activation in cultured bovine adrenal medullary cells. JF - Molecular Pharmacology JO - Mol Pharmacol SP - 1041 LP - 1047 VL - 46 IS - 6 AU - M Tsutsui AU - N Yanagihara AU - E Miyamoto AU - A Kuroiwa AU - F Izumi Y1 - 1994/12/01 UR - http://molpharm.aspetjournals.org/content/46/6/1041.abstract N2 - We have investigated the activation of Ca2+/calmodulin-dependent protein kinase II (CaM kinase II) in cultured bovine adrenal medullary cells. The activation was assayed as an increase in the Ca(2+)-independent (autonomous) activity of CaM kinase II, using the synthetic substrate Syntide-2. Incubation of cells with acetylcholine increased the Ca(2+)-independent activity in a time (20 sec to 5.0 min)- and concentration (10-300 microM)-dependent manner. These curves were closely correlated with those of catecholamine secretion and tyrosine hydroxylase activation. Removal of extracellular Ca2+ completely abolished the stimulatory effects of acetylcholine on the Ca(2+)-independent activity, as well as on catecholamine secretion and activation of tyrosine hydroxylase. Nicotine but not muscarine increased the Ca(2+)-independent activity as potently as did acetylcholine, and hexamethonium but not atropine completely blocked the acetylcholine-induced increase. In 32P-labeled cells, acetylcholine stimulated the phosphorylation of a 50-kDa protein that was immunoprecipitated with an anti-brain CaM kinase II antibody. These results suggest that acetylcholine stimulates CaM kinase II activity through nicotinic acetylcholine receptor-mediated influx of Ca2+ and that the activation of CaM kinase II is closely related to catecholamine secretion and tyrosine hydroxylase activation in cultured adrenal medullary cells. ER -