BLOCKADE OF SUPEROVULATION IN IMMATURE RAT BY INCREASED BRAIN SEROTONIN

C.KORDON, F.JAVOY, G.VASSENT and J.GLOWINSKI. Blockade of superovulation in the immature rat by increased brain serotonin, European J. Pharmacol. 4 (1968) 169-174. The MAO inhibitor nialamide blocks ovulation in chorionic gonadotropin-treated immature female rats. Prior blockade of catecholamine synthesis by α-methyl-p-tyrosine (α-MT) does not interfere with this effect, whereas blockade of serotonin synthesis by p-chlorophenyl-alanine (PCPA) antagonises the action of nialamide; 5-hydroxytryptophan (5-HTP), but not dihydroxyphenylalanine (DOPA), inhibits ovulation. Determination of serotonin and noradrenalin brain levels shows that ovulation is only affected by increased brain serotonin. It is concluded that this amine has a specific inhibitory effect on the release of pituitary ovulation hormone. © 1968.