[Effect of substance P on dopamine-beta-hydroxylase and phenethanolamine-N-methyltransferase in the adrenal glands of rats].

Resulting from literature data concerning interactions between catecholamines and Substance P (SP) the influence of SP on the activity of dopamine-beta-hydroxylase (DBH) and phenylethanolamine-N-methyltransferase (PNMT) was studied in rat adrenals. Intraperitoneal application of SP (500 micrograms/kg) to male Wistar rats 15 minutes before decapitation induced a decrease of PNMT activity in the adrenals, while DBH activity remained unchanged. After incubation of adrenals with SP (10(-6) mol/l) a decrease of activity of both PNMT and DBH was observed. The experimental results are discussed in connection with a normalizing function of SP during stress induced disorders.