Testicular involution in elderly men: comparison of histologic quantitative studies with hormone patterns.

An endocrinologic and quantitative histologic study was carried out in 64 elderly men who underwent orchidectomy owing to prostatic carcinoma. The men were classified into age groups (decade of life), and each group was subdivided into group A (testes with complete spermatogenesis in most tubules) and group B (testes showing maturation arrest of spermatogenesis in most tubules). Up to 80 years of age, men of group A showed hormone levels and testicular parameters similar to those of young control men. From 50 to 60 years of age, men of group B showed a significant decrease in testicular volume, tubular volume, tubular length, number of germ cells, Sertoli cells and Leydig cells per testis, and plasma testosterone levels, whereas the tunica propria thickness and plasma levels of both follicle-stimulating hormone and luteinizing hormone were increased.