THE 'EARLY ANDROGEN SYNDROME' IN THE GUINEA-PIG

Abstract

SUMMARY When testosterone propionate was administered to pregnant guinea-pigs over a short period (days 33–37) of gestation a high proportion of the female offspring exhibited a characteristic syndrome. The time of the first vaginal opening was delayed and its duration reduced. Subsequent periods of opening were fairly regular in occurrence but were shorter in duration than in normal animals; the 'cycle' length was usually slightly longer. Continuous vaginal opening was not observed but during the periods of opening, vaginal smears containing many cornified cells and no leucocytes were obtained. During the periods of vaginal opening no lordosis response to manual stimulation could be elicited nor did the animals mate when run with males. The increase in body weight was normal up to about 150 days of age and slightly, but not significantly, less than that of controls between 150 and 200 days of postnatal life. As adults some masculinization of the external genitalia was observed. At autopsy the weights of the uteri, ovaries, adrenal and anterior pituitary glands were much greater than those of control animals at any stage of the cycle. Histological examination showed that the ovaries contained many antral follicles but no luteal tissue. Enlargement of the glands and metaplastic changes in the epithelium were observed in the uteri. The pituitaries showed an excess of cells containing large, densely packed eosinophilic granules. This early androgen syndrome is compared with that produced by hypothalamic lesions in the guinea-pig and with the changes produced in other species by the administration of androgenic steroids during prenatal or early postnatal life.