Quantitative analysis of the seminiferous epithelium in human testicular biopsies, and the relation of spermatogenesis to sperm density.

Quantitative analysis of the seminiferous epithelium was performed in bilateral testicular biopsy specimens from 14 patients with sperm counts ranging from 0 to 89 million/ml. All Sertoli cells and germ cells within each seminiferous tubule cross-section were counted in all biopsies. Results were expressed either as number of cells per unit length of seminiferous tubule circumference or as number of cells per Sertoli cell. Results were correlated with sperm count (millions per milliliter), total sperm count (millions per ejaculate), and age. A significant correlation between sperm density and germ cell counts was demonstrated. Coefficients of correlation were higher when results were expressed per unit of tubular wall length than when expressed per Sertoli cell. In men with sperm counts below 5 million/ml the number of germ cells in the biopsy was lower than in men with higher sperm counts. Spermiogenesis appeared to be most affected. In this group of patients an adverse effect of age on spermatogenesis was noted.