Clorgyline effect on pineal melatonin biosynthesis in adrenalectomized rats pretreated with 6-hydroxydopamine
The response to administration of the specific monoamine oxidase A (MAO-A) blocker clorgyline was investigated in adult male Sprague-Dawley rats which were adrenalectomized four days prior to treatment or were additionally sympathectomized as newborns by injection of 6-hydroxydopamine. In both groups, the contents of pineal indoles melatonin and N-acetylserotonin were augmented, and the contents of 5-hydroxyindoleacetic acid and 5-hydroxyindoletryptophol decreased 90 min following clorgyline injections when compared to rats receiving saline. The observed responses were less pronounced in rats both adrenalectomized and sympathectomized. The results are in line with the hypothesis that preservation from oxidation of both MAO-A substrates, noradrenaline and serotonin, upon clorgyline administration contributes to the observed increase in melatonin biosynthesis thought to be associated with the antidepressant effects of MAO inhibition.
KeywordsPineal Gland Superior Cervical Ganglion Melatonin Synthesis Pineal Melatonin BioI Psychiatry
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- Lewy A (1983) Biochemistry and regulation of mammalian melatonin production. In: Relkin R (ed) The pineal gland. Elsevier, New York, pp 77–128.Google Scholar
- Oxenkrug GF (1991) The acute effect of monoamine oxidase inhibitors on serotonin conversion to melatonin. In: Sandier M, Coppen A, Harnett S (eds) 5-Hydroxytryptamine in psychiatry. A spectrum of ideas. Oxford University Press, pp 98-109.Google Scholar
- Oxenkrug GF, McCauley RB (1987) The effect of MAO inhibitors on melatonin synthesis: mechanism and clinical implication. Pharmacol Toxicol 60 [Suppl] 1: 36.Google Scholar
- Oxenkrug GF, McCauley RB, Mclntyre IM, Filipowicz C (1984) Effect of clorgyline and deprenyl on rat pineal melatonin. J Pharm Pharmacol 36: 55W.Google Scholar