THE PHYSIOLOGY OF PREGNANCY IN THE RAT. THE COMBINED ACTION OF MALE AND FEMALE HORMONES (TESTOSTERONE PROPIONATE AND STRONE)

¹ Institute of Animal Genetics, University of Edinburgh

1. An antagonistic action was observed in the ovariectomised rat between strone and testosterone propionate (male hormone), the latter annulling the strogenic effect of the former.

2. In the pregnant rat, male hormone did not overcome the interruptive action of strone even in very large amounts.

3. Such amounts were themselves interruptive in effect when administered alone at the same stage of gestation.

4. These amounts had no strogenic effect on ovariectomised rats.

5. It is concluded that the interruptive effect of male hormone on pregnancy is probably specific, and may be by way of the anterior pituitary or other ductless gland.

The expenses of this investigation were defrayed by grants from the Carnegie Trust and the Medical Research Council.