Increased monoamine oxidase activity following repeated electroshock seizures

Abstract

We Have recently reported that chronic electroconvulsive seizures (ECS) lead to a long‐lasting increase (up to 6 weeks) in the activity of monoamine oxidase (MAO) in the brain of rats (Pryor and Otis, 1970). Other investigators have shown increased levels of norepinephrine (NE) and 5‐HT, more rapid clearance of intracisternally‐injected [3H]HNE (Kety, Javoy, Thierry, Julou and Glowinski, 1967), and increased tyrosine hydroxylase activity (Musacchio, Julou, Kety and Glowinski, 1969) at 24 h after a series of two ECS daily for 7 days. Together, these data suggest a sustained activation of the 5‐HT and/or NE systems following chronic ECS. We now report the results of a series of experiments in which some of the potential variables that may be involved in the MAO response were investigated and that indicate some biochemical specificity of the response. In these experiments, succinate dehydrogenase (SDH) activity was also assayed to assess possible nonspecific effects of repeated seizures on mitochondrial metabolism and catechol O‐methyltransferase (COMT) activity was determined to see if this extracellular degradative enzyme for NE was affected in the same way as MAO located intracellularly in the mitochondria.

Neurophysiological Measures and Visual Averaged Evoked Responses in Psychiatric Patients

“…Monoamine oxidase plays a central role in the metabolism of biogenic amines (8) and in animal experiments it has been shown that there is a correla tion between their turnover rate and the brain monoamine oxidase activity (10,11). Those results together with the finding that the MAO activity is reduced in the brains of alcoholics who have committed suicide led us to suggest that the brain MAO activity reflects the rate of the monoaminergic turnover (6).…”

Kinetic evaluation of platelet monoamine oxidase following relaxation in chronic anxiety

“…Alteration in M A 0 activity in animals subjected to stress has previously been demonstrated, with acute stress producing reduced activity (13), and prolonged or chronic stress resulting in elevated activity (14,15,28,29). These findings are consistent with the model previously proposed (30) suggesting differential effects of acute and chronic stress: under acute stress, MA0 activity is reduced which, in turn, potentiates the actions of neurotransmitters at their receptors; this would represent the "flight or fight" condition.…”