Changes in Enzymes involved in the Biosynthesis and Metabolism of Noradrenaline and Adrenaline after Psychosocial Stimulation

Abstract

THE important role of catecholamines in behaviour has been recognized¹. Increased adrenaline and noradrenaline excretion has been observed in anxiety-provoking situations and in states of anger and aggression^2,3. Drugs used in affective disorders cause marked changes in uptake, storage, release and metabolism of the neurotransmitter noradrenaline in the peripheral and central nervous systems^4,5. Because of the growing understanding of the implication of catecholamines in behavioural changes, we examined the effect of psychosocial stimulation and deprivation on the activity of the enzymes involved in the biosynthesis and metabolism of catecholamines. Groups of mice were raised in social isolation or were subjected to prolonged and increased social interaction, and the catecholamine synthesizing (tyrosine hydroxylase and phenylethanolamine N-methyltransferase) and metabolizing (monoamine oxidase and catecholamine-O-methyl transferase) enzymes were examined in the adrenal gland. We wish to report marked changes in enzymes involved in catecholamine synthesis and metabolism in the adrenal glands of these mice.