Substance P inhibits catecholamine biosynthesis stimulated by carbamylcholine in cultured adrenal chromaffin cells.
The effect of substance P on catecholamine biosynthesis was examined using cultured bovine adrenal chromaffin cells as a model for the sympathoadrenergic system. Substance P markedly inhibited the formation of [14C]catecholamines from L-[14C]tyrosine stimulated by cholinergic agonist, but caused no significant effect on the biosynthesis stimulated by depolarizing agent. In addition, this inhibitory action was completely prevented by the addition of substance P antagonists. Under the conditions in which the inhibition of catecholamine biosynthesis was observed, substance P also inhibited the influx of extracellular 45Ca2+ into these cells, and this inhibitory action on Ca2+ influx was almost identical to that on the biosynthesis. These results provide evidence for a possible role of substance P as a putative neuromodulator in the sympathoadrenergic system.
Houchi
H
H
Department of Pharmacology, Tokushima University School of Medicine, Japan.
Teraoka
K
K
Oka
M
M
Murakumo
Y
Y
Morita
K
K
D000313:Adrenal Medulla / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D002217:Carbachol / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D002395:Catecholamines / Q000096:biosynthesis*; D002417:Cattle; D002478:Cells, Cultured; D004336:Drug Antagonism; D013373:Substance P / Q000494:pharmacology*
D002395:Catecholamines; D013373:Substance P; D002217:Carbachol