Immunocytochemical localization of hFSH as an index of Sertoli cell function in the human testis

The FSH receptor in the human testis has not been well characterized in vivo. Using an immunoperoxidase technique we have attempted the immunocytochemical localization of FSH in testicular tissue from patients with a variety of disorders including oligo- or azoospermia (N = 6), cryptorchidism (N = 3), and prostatic carcinoma (N = 3). Specific staining for hFSH was observed inside the seminiferous tubule, generally near the basal membrane in all except the cryptorchid patients. Specific staining was also localized in the luminal area of the seminiferous tubule. In most cases, FSH-positive cells were also found in the interstitium, with a minority of the cells being macrophages. The latter were more prevalent in the undescended testes and in orchiectomy specimens from patients with prostatic cancer. The pattern of FSH localization observed in this study probably represents receptorbound hormone, and may reflect damage to the Sertoli cell and its tight junctions. Further study of the changes in receptor distribution as an indication of Sertoli cell malfunction, may be helpful in our understanding of human testicular disorders.