Abstract
Permanent changes in the testis were induced in mice given daily injections of estradiol-17β for 15 days starting on the day of birth, 20μg for the first 10 days and 40μg for the following 5 days. Sequential changes in the testis during or after the neonatal estrogen injections were examined under an electronmicroscope. One to seven daily injections of estrogen caused no change in the testis. In 10-to 20-day-old mice which had been given estrogen injections for 10-15 postnatal days, however, multinucleated gigantic spermatocytes were found in high frequency in the seminiferous tubules, and plasma membranes of both the germ cells and the myoid cells of the lamellated connective tissue surrounding the tubules frequently became discontinuous or underwent disintegration. Partial disorganization took place in some of the tubules. In 30-day-old mice which had been given estrogen injections for 15 postnatal days, the testis contained atrophic Leydig cells and the tubules with a thin seminiferous epithelium consisting of spermatogonia, spermatocytes and immature Sertoli cells.
