Arachidonic acid stimulates phosphoinositide metabolism and catecholamine release from bovine adrenal chromaffin cells.
Arachidonic acid (AA) evoked a dose-dependent increase in the accumulation of inositol phosphates in cultured bovine adrenal chromaffin cells, and this effect was specific for AA. AA also induced a rise in [Ca2+]i, but this rise was markedly reduced by removal of extracellular Ca2+. AA-induced accumulation of inositol phosphates was absolutely dependent on extracellular Ca2+, and nicardipine and nifedine partially reduced it but verapamil had no effect. Moreover, AA dose-dependently stimulated catecholamine release from chromaffin cells in the presence of ouabain, and this effect was specific for AA. AA-induced catecholamine release in the presence of ouabain was also inhibited by nicardipine and nifedipine but not by verapamil. Furthermore, the phospholipase C inhibitor neomycin inhibited the release. These results taken together suggest that AA stimulates catecholamine release in the presence of ouabain by stimulation of phosphoinositide metabolism in a Ca2(+)-dependent manner.
Negishi
M
M
Department of Cell Biology, Osaka Bioscience Institute, Japan.
Ito
S
S
Hayaishi
O
O
D000313:Adrenal Medulla / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology; D002121:Calcium Channel Blockers / Q000494:pharmacology; D002395:Catecholamines / Q000378:metabolism*; D002417:Cattle; D002478:Cells, Cultured; D005230:Fatty Acids, Nonesterified / Q000494:pharmacology; D007294:Inositol / Q000378:metabolism; D007295:Inositol Phosphates / Q000378:metabolism; D007700:Kinetics; D010042:Ouabain / Q000494:pharmacology; D010716:Phosphatidylinositols / Q000378:metabolism*
D001095:Arachidonic Acids; D002121:Calcium Channel Blockers; D002395:Catecholamines; D005230:Fatty Acids, Nonesterified; D007295:Inositol Phosphates; D010716:Phosphatidylinositols; D016718:Arachidonic Acid; D007294:Inositol; D010042:Ouabain; D002118:Calcium