Pargyline prevents MPTP-induced parkinsonism in primates

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is a neurotoxin which produces permanent parkinsonism in human and nonhuman primates. Treatment of squirrel monkeys with pargyline, a monoamine oxidase (MAO) inhibitor, prevents both clinical and neuropathological evidence of the neurotoxic effects of MPTP. Pargyline also inhibits conversion of MPTP to 1-methyl-4-phenylpyridinium ion (MPP+), a metabolic step that occurs rapidly after administration of MPTP in animals not treated with pargyline. It is proposed that the conversion of MPTP to MPP+, possibly involving MAO, may be important for the neurotoxic effects of MPTP to take place, and MPTP itself may not be the neurotoxic agent.

An open trial of pargyline in the treatment of attention deficit disorder, residual type

Twenty-two patients who met the Utah criteria for attention deficit disorder, residual type (hyperactivity, minimal brain dysfunction in adults) received an open trial of pargyline (Eutonyl). Of these 22 patients, 13 (59%) showed a moderate to marked therapeutic response. Clinically useful features of pargyline in the treatment of attention deficit disorder, residual type are that its duration of action is greater than 24 hours and that it has not been abused. Pargyline inhibits monoamine oxidase, type B, and its therapeutic efficacy is compatible with the hypothesis that decreased phenethylaminergic function, dopaminergic function, or both play a role in the etiology of the disorder.

Pargyline-induced mania in primary affective disorder: case report

A case is described of a 47-year-old man who developed a manic psychosis while receiving pargyline treatment for concurrent depression and hypertension. The pharmacologic actions of pargyline are discussed with regard to its partial selectivity for MAO-B and presumed action in dopamine systems, and clinicians are alerted to this uncommon drug reaction.

Role of 5HT in the morbidity of cerebral infarction-a study in the gerbil stroke model

Cerebral infarction was produced by unilateral carotid ligation in the gerbil, and 5HT levels in the cerebral hemispheres were assayed 3.5 hours later. A bilateral fall as confirmed, with the greatest change occurring on the side of carotid ligation in animals showing the clinical sequelae of infarction. Neither absolute levels nor right left differences in 5HT content related directly to the nature or prevalence of neurological morbidity. Neither putative 5HT receptor antagonists nor agents causing increasing brain 5HT levels produced consistent changes in the prevalence of neurological morbidity. It is argued that the fall in 5HT in a cerebral infarct is more likely to be due to reduced synthesis and turnover than to release of the amine into the synaptic cleft. These findings cast doubt on the hypothesis that a significant part of the morbidity and mortality of cerebral infarction is due to the sequelae of 5HT release.

Comparative behavioral effects of clorgyline and pargyline in man: a preliminary evaluation

The antidepressant and other behavioral effects of clorgyline, a preferential inhibitor of monoamine oxidase (MAO) type A, were compared with those of pargyline, a preferential inhibitor of MAO type B, in 16 depressed patients. In a subgroup of more severely depressed patients, clorgyline treatment for 4 weeks resulted in significant improvement on both observer-rated and self-rated scales, while minimal changes occurred during pargyline treatment. Similarly, in a crossover study that included 8 patients examined with multiple scales, clorgyline had generally greater antidepressant and antianxiety effects than did pargyline, although pargyline had some activating effects and also tended to produce more side effects. MAO type A inhibition may be more important than MAO type B inhibition for antidepressant efficacy.

Elevation of plasma-prolactin by monoamine-oxidase inhibitors

Plasma-prolactin levels doubled in depressive patients treated with the monoamine-oxidase inhibitors, clorgyline and pargyline. The absence of significant changes in plasma-cortisol in the same patients suggests that the increases in prolactin are not attributable to non-specific effects of stress.