Hormonally Responsive Areas of the Reproductive System of the Male Guinea Pig. II. Effects of Estrogens

Abstract

The administration of 2.5 µg of diethylstilbestrol (DES) to intact male guinea pigs for 10 or 30 days resulted in cytological changes in their reproductive tracts. These changes were most marked in those structures derived from the urogenital sinus. Treatment with DES affected both the epithelium and the stromal components of the tissues to a varying degree. Mucification of the epithelium of the distal segments of the vasa deferentia, seminal vesicles, and the sinus portion of the uterus musculinus was observed. Proliferation of the sinus epithelium of the common ejaculatory chamber also occurred, being most marked over the verumontanum. There was also proliferation and squamous metaplasia of the same areas after 30 days administration. The secretory portions of the seminal vesicles, prostate, and coagulating glands, and the vas deferens throughout its length, underwent atrophy and squamous metaplasia. After 30 days of DES treatment, atrophy of the epididymis was observed; the distal portion of the cauda epididymidis was most affected. Atrophy of the spermatogenic epithelium was noted in the animals that received DES for 30 days. An increase in the ground substance of the stroma of the verumontanum was also observed. Hypertrophy of the smooth muscle of the verumontanum and of the seminal vesicles was observed in some animals after 30 days of treatment with DES. The administration of estradiol (2.5 µg/day for 30 days) or estradiol benzoate (10 µg/day for 10 days) was less effective than DES in causing the above lesions. This indicates that the phenomena observed are dependent upon the nature of the estrogenic stimulus as well as on the dose and duration of the treatment.