PRODUCTION OF PERSISTENT CHANGES IN THE GENITAL ORGANS OF IMMATURE FEMALE RATS TREATED WITH TESTOSTERONE1

Abstract

Treatment of newborn [female] albino rats with 1 mg. of testos-terone daily during the first 30 days of life causes deficient development of the ovaries, uterus and vagina. These organs remain in a state of hypoplasia for at least 1 mo. after discontinuation of treatment although during this time the body wt. of the animals is approx. 5 times larger than at the time when injs. were discontinued. Since at the end of the observation period, the av. wt. of the untreated controls approx. equals that of the injected animals, the inhibition of development is limited to the above mentioned sex organs. The clitoris and kidney which increase in size as a result of testosterone adm. persist in a condition of marked hypertrophy after discontinuation of the injs. In the very immature rat, testosterone inhibits uterine development although at a later period of life, this hormone is known to exert a marked uterus stimulating action. The inhibition of sex organ development caused by testosterone at an early age persists and prevents the onset of puberty in the rat.