Two-generation reproductive toxicity study of tributyltin chloride in malerats

A 2-generation reproductive toxicity study of tributyltin chloride (TBTCl) was conducted in male rats using dietary concentrations of 5, 25, and 125 p pm TBTCl to evaluate its effect on sexual development and the reproductive system. Fl males were killed on postnatal day 119 and F2 males were killed on postnatal day 91. TBTCl affected the male reproductive system of rats. T he weights of the testis and epididymis were decreased and homogenization-r esistant spermatid and sperm count were reduced mainly in the 125 ppm TBTCl group. Histopathologic changes were also observed in the testis of this gr oup and included vacuolization of the seminiferous epithelium, spermatid re tention, and delayed spermiation. However, the changes were minimal in natu re. The weight of the ventral prostate was decreased to 84% of the control value in the 125 ppm group in the F1 generation and decreased to 84 and 69% of the control value in the 25 ppm and 125 ppm TBTCl groups, respectively, in the F2 generation. The serum 17 beta -estradiol concentration was also decreased to 55% of the control value in the 125 ppm group in the F1 genera tion and decreased to 78 and 57% of the control value in the 25 ppm and 125 ppm TBTCl groups, respectively, in the F2 generation. However, the serum c oncentrations of luteinizing hormone (LH) and testosterone were not decreas ed in these groups. These changes corresponded with those caused by aromata se inhibition and therefore TBTCl might be a weak aromatase inhibitor in ma le rats.