[Purification of pineal antigonadotropic factor (author's transl)]

Pineal activity on hypothalamo-hypophyso genital axis is well established. The mechanism is not simple, since progonadotropic or/an antigonadotropic activity were described. The biochemical isolation of the potent factor has been assayed. Several substances: melatonin, AVT, peptides have antigonadotropic properties. In this paper, we report many experiments concerning isolation and purification by several chromatographies of the factor (probably peptidic), that we believe to be responsible of antigonadotropic activity. Biological activity of the substance is proved by "in vitro" methods and radio immunoassays. This component is quite pure because electrophoresis on gel polyacrylamid reveals only one strip. Gel Sephadex G10 chromatography indicates a probable MW is between 500 and 1,000. This component causes an important inhibition of pituitary LH discharge (in vitro methods).