Short-time effects of taxol on the seminiferous epithelium of the rat.

The effect of taxol, an inhibitor of microtubule degradation, on the seminiferous epithelium was studied. Taxol arrested spermatogenesis at metaphase in both mitotic and meiotic germ cell division. Microtubules were seen to accumulate, especially in the cytoplasm of the spermatogonia, and also in the early spermatids and Sertoli cells. No microtubule accumulation was observed in germ cells during meiotic prophase. Formation of the flagellum was affected in developing spermatids. Peculiar lamellar structures, probably derived from degenerating mitochondria, were seen in the cytoplasm of late spermatids and Sertoli cells. The results are compared with the effects of other mitotic inhibitors such as colchicine and vinca alcaloids.