Abstract
Many cell types have reportedly been shown to respond to extracellular stimulation with a rapid increase in phosphatidylinositol turnover. However, there has been a discrepancy concerning the relationship between catecholamine secretion and the phosphatidylinositol turnover. The effect of phospholipase C inhibitors including 2-nitro-4-carboxyphenyl N, N'-diphenylcarbamate, spermine and spermidine on acetylcholine-stimulated catecholamine secretion was studied in perifused pig adrenal medulla. Pretreatment of pig adrenal medulla with all the inhibitors employed in the present study blocked the increase of catecholamine output induced by acetylcholine. On the other hand, diacyiglycerol itself was found to release catecholamine from the perifused pig adrenal medulla. These results support the idea that there is a close relationship between phosphatidylinositol turnover and catecholamine secretion.
