Deformation of the rat Sertoli cell by oral administration of carbendazim (methyl 2-benzimidazole carbamate).

Carbendazim (methyl 2-benzimidazole carbamate; MBC) has been reported to disrupt the microtubules of Sertoli cells in the rat, suggesting that the cells exposed to carbendazim would fail to maintain their shape due to the loss of their cytoskeleton. The present study was performed to determine whether exposure to carbendazim induced Sertoli cell deformation. For this purpose, changes in the shape and position of Sertoli cell nuclei, that appear to be associated with changes in the shape of the cells themselves, were observed in stage VI-VII seminiferous tubules of rat testis at 3 hours following treatment. Light microscopy and computer-aided three-dimensional reconstruction were also performed to survey the outline of the body. In the controls, parallel-positioned nuclei (nuclei with their longer axis parallel to the basement membrane), perpendicular-positioned nuclei (nuclei with their longer axis perpendicular to the basement membrane), and round-shaped nuclei (nuclei showing a round or regular triangular profile) accounted for approximately 52%, 35%, and 13% of the total, respectively. In Sertoli cells showing carbendazim-induced sloughing of germ cells, however, parallel-positioned nuclei accounted for 21% and the round-shaped nuclei for 51% of the total. Approximately 69% of perpendicular-positioned nuclei were located in the basal part of the cells in the controls, compared with 95% in tubules showing carbendazim-induced sloughing. These changes in individual parameters were significantly different (alpha < 0.05). Light microscopy and computer-aided reconstruction indicated that the body region of Sertoli cells in the control testis was columnar in shape, whereas that of Sertoli cells that showed sloughing was conical. These findings suggest that Sertoli cell cytoplasm, following carbendazim-induced sloughing, moves toward the base of the cellular axis.