The Antigonadotropic Factor. Species Specificity and Organ Specificity

There are contradictions to be found in literature as to the specificity of the antigonadotropic factor. Bachmann, Collip and Selye, 1 Fluhmann, 2 Meyer and Gustus, 3 Brandt and Goldhammer, 4 Twom-bly, 3 Sulman, 6 Thompson, 7 hold that the species specificity of the antigonadotropic factor is Droved. Gegerson, Clark and Kurzrok, 8 Rowlands, 9 Parkes and Rowlands, 10 however, presented evidence against the species specificity. Recently Collip 11 reported similarly. However, the latter workers had other test objects (inhibition of ovulation in the mated rabbit or of the oestral cycle in the normal rat) than the former, 1 2 3 4 5 6 7 and than we did. Fluhmann, 2 Brandt and Goldhammer, 4 Gegerson, Clark and Kurzrok, 8 Parkes and Rowlands 10 are opposed to the presence of an organ specificity. Selye, Collip and Thompson, 12 however, favor it. To investigate this we performed the following experiments. We used the technique described in our first report, 13 that of the exact titration of the gonad-otropic hormone against adequate amounts of the antigonadotropic factor in infantile female rats and mice.

While studying the species specificity and organ specificity it was essential to pay attention to the minimal and maximal values. We, therefore, thoroughly titrated maximal amounts of the antigonadotropic factor (50-100-200 PAU or PSAU∗) against minimal amounts of such gonadotropie factor foreign to the species or to the organ, (1-5-10 RU). In control experiments we confirmed the titre of the gonadotropie and that of the antigonadotropic factor. The results are shown in Table I.

Table I shows (Experiments 1 and 4) that the antigonadotropic sera are active against the gonadotropie preparation used for the preliminary treatment. In contrast to this 200 PSAU (Experiment No. 6) cannot inactivate one RU of gonadotropie hormone from another species, i. e., an antigonadotropic serum has less than 0.5% of its effectiveness if used against a heterologous gonadotropie factor.