Catecholamine metabolism in pargyline treated rats exposed to stress.

The administration of pargyline to normal rats enhanced the adrenal catecholamines noradrenaline + adrenaline content, tyrosine hydroxylase (TH) and catechol -0-methyl transferase (COMT) activity together with a reduction in monoamine oxidase (MAO) activity. The pargyline pretreated rats exposed to acute stress exhibited a significant increase in adrenal catecholamine content and COMT activity with no change in TH and phenylethanolamine-N-emthyl transferase (PNMT) activity as compared to normal stressed rats. However, adrenal MAO activity was decreased in pargyline pretreated stressed rats. Thus, these observations tend to suggest that pargyline treatment before exposure to stress considerably influence the usual stress response in term of catecholamine metabolism.