The effect of anti-gonadotropic serum on the reproductive organs of the normal animal

It is now well established that anti-gonadotropic activity can be evoked in blood serum by the prolonged injection of animals with gonadotropic extracts, and such extracts from a variety of sources all appear to be effective. Thus extracts of human urine of pregnancy and pituitary extracts were used by Bachman, Collip, and Selye (1934); pituitary extracts by Fluhmann (1935,a ,b ), and Eichbaum and Kindermann (1935); pregnant mare serum by Gustus, Meyer, and Dingle (1935), and urine from teratoma testis cases by Twombly and Ferguson (1934). The recent work of Twombly (1936) lends support to the view that the development of the anti-substances in sera in response to continued administration of hormone preparations is due to the introduction of heterologous proteins with antigenic properties. He has shown that when homologous extracts are injected, such as urine of pregnancy extracts to women, no anti-substances can be detected in the serum. Another relevant experiment was carried out by Du Shane, Levine Pfeiffer, and Witschi (1935) who united parabiotically two female rats, one hypophysectomized, the other ovariectomized. The gonadotropic hormone of the pituitary of the ovariectomized one sufficed to maintain the ovaries of the hypophysectomized one in a functional state for over a year without any sign of interference due to the production of antihormones. A similar view, based on a comparable experiment, has been put forward by Martins (1935). On the other hand, Gustus, Meyer, and Dingle (1935) prepared from serum of pregnant mares a protein-free extract of gonadotropic hormone which produced an anti-substance in the blood of monkeys, although the latter gave no precipitin reaction with the purified hormone.