Effects of Androsterone and Testosterone on Oestrous Cycle of Rats

ConclusionsThe observed results demonstrate that daily injections of 0.5 to 3 mg. of testosterone in sesame oil and of 3.0 to 5.0 mg. of androsterone in sesame oil into normal mature female rats leads to a suppression of the oestrous cycles, as expressed by the vaginal smear, during the 16-day period of injection.These observations agree with the findings of Robson that testo-sterone causes total suppression of the oestrous cycle in mice. It seems quite adequate to the writer to assume that the pure crystalline androgenic substances, testosterone and androsterone, have an action upon the pituitary gland of the female rat in a manner con-sistent with the interpretation offered by Moore and Price. Nothing presented by these experiments, however, would rule out the possibility of a direct effect upon the ovary by crystalline androsterone or a possible neutralization of the action of estrogenic sub-stances upon the female tract by androsterone.