To determine whether there are any deleterious changes in the human testis after vasectomy, we obtained testicular biopsy specimens from 31 healthy men undergoing vasectomy reversal and from 21 healthy, fertile volunteers. Morphometric analyses of these specimens revealed a 100 per cent increase in the thickness of the seminiferous tubular walls (P less than 0.001), a 50 per cent increase in the mean cross-sectional tubular area (P less than 0.001), and a significant reduction in the mean number of Sertoli cells (P less than 0.01) and spermatids (P less than 0.01) per tubular cross section in the post-vasectomy group, as compared with the control group. Focal interstitial fibrosis was observed in 23 per cent of the specimens from the post-vasectomy group and in none from the control group. There was a significant correlation (P less than 0.01) between interstitial fibrosis and infertility in patients who underwent a surgically successful vasectomy reversal (sperm in the ejaculate). None of the other measured characteristics correlated with infertility after vasectomy reversal. We conclude that significant morphologic changes occur in the human testis after vasectomy. The presence of focal interstitial fibrosis was associated with a high incidence of infertility in this series.

To evaluate the origin of seminal prostaglandins, genital tract fluids were analysed for prostaglandin content in two clinical situations. Six patients delivered semen samples before and after vasectomy. In these patients the prostaglandin concentration remained essentially unchanged although sperm density decreased to zero. In another patient secretory products from the testis and epididymis, and the ejaculate representing mainly the secretion of the seminal vesicles and the prostate gland, were collected separately. Secretions obtained from the testis and epididymis did not contain detectable amounts of prostaglandins, whilst in the ejaculate from the same patient the concentration was within normal limits. The results of the study show that the testis and epididymis do not contribute significantly to the prostaglandin content of human seminal fluid. The previous assumption that the seminal vesicles are the main source of seminal prostaglandins is thus supported.

To evaluate the origin of seminal prostaglandins, genital tract fluids were analysed for prostaglandin content in two clinical situations. Six patients delivered semen samples before and after vasectomy. In these patients the prostaglandin concentration remained essentially unchanged although sperm density decreased to zero. In another patient secretory products from the testis and epididymis, and the ejaculate representing mainly the secretion of the seminal vesicles and the prostate gland, were collected separately. Secretions obtained from the testis and epididymis did not contain detectable amounts of prostaglandins, whilst in the ejaculate from the same patient the concentration was within normal limits. The results of the study show that the testis and epididymis do not contribute significantly to the prostaglandin content of human seminal fluid. The previous assumption that the seminal vesicles are the main source of seminal prostaglandins is thus supported.

Spermatogenesis has been studied in testicular biopsies by means of microfluorometric assessment of the DNA-DNP complex using ethidium bromide in 10 men with histologically normal spermatogenesis and in 10 men with histologically reduced spermatogenesis. The expected haploid DNA value was found in the round spermatids, whereas only 70% of the haploid fluorescence value was found in the elongated spermatids and around 60% in the testicular spermatozoa. No difference was found in the mean fluorescence values between the pathological group and the controls. it is suggested that structural changes or an increase in basic nuclear proteins gradually exclude the ethidium bromide from the binding to the DNA molecule and that this phenomenon occurs concomitantly with a decrease in double-stranded RNA. The difference in fluorescence intensity before and after RNAase treatment was regarded as an approximate estimate of the RNA content. There was a significant decrease of these values during spermatogenesis.