Testicular toxicity and mechanisms of chlorotoluron compounds in the mouse.

ABSTRACT Previous studies have reported that chlorotoluron has adverse effects on male mice. Few studies, however, have investigated the mechanism of the action of these herbicides. The study of the effects of chlorotoluron and atrazine ingestion on male mice reproductive function during a critical developmental period, the peripubertal period, is reported here. Chlorotoluron and/or atrazine were administered by PO gavage to mice from day 27 to day 52. The decreased weight ratio of mouse testis to body weight resulted in a reduction in the relative testis weight. Histological study of testis showed that the seminiferous epithelium arrayed loosely and disorderedly, spermatogenic cells became shed, and fewer layers were formed. With the use of an electron microscope, it was noted that mitochondria in the seminiferous epithelium appeared vacuolated; karyotheca swelled and bent. In addition, the number of Sertoli cells was reduced, and part of the tight junction was destroyed. The results of the present study demonstrated that herbicides in all administrated doses caused detrimental changes in mice. The toxic effects of chlorotoluron were more potent than those of atrazine when administrated alone. Moreover, the two compounds have synergistic toxic effects with combination use. All dose paradigms induced degeneration and severe pathological changes in a manner of dose response.