EN
Sertoli cell population and histology were studied in testes of unilateral cryptorchid goats. Histomorphological and electron microscopic techniques were employed. The results demonstrated that the number of Sertoli cell per testis was significantly (p < 0.05) higher in the descended scrotal testes of unilateral cryptorchid bucks compared with the right and left testes of the normal bucks, respectively. However there was no significant difference (p > 0.05) on comparing the number of Sertoli cells in the scrotal testes of the unilateral cryptorchid bucks with the paired testes of the normal bucks. Significant differences were not observed in the dimensions of the Sertoli cell nuclei in the retained, scrotal testes of the cryptorchids and the testes of the normal bucks. The Sertoli cells of the descended scrotal testes of the cryptorchid bucks and those of the normal bucks showed histological evidence of normal activity. Degeneration of Sertoli cells was observed in the retained testis of the cryptorchid bucks. The failure of one testis to descend most probably influenced compensatory hyperplasia of Sertoli cells and enhanced function of the cells in the descended testis of the unilateral cryptorchids. (Folia Morphol 2016; 75, 3: 355–363)