Pre- and postnatal exposure to 3,3',4,4'-tetrachlorobiphenyl: I. Effects on breeding ability and sperm fertilizing ability in male mice.

This study investigated the effects of 3,3',4,4'-tetrachlorobiphenyl (TCB) on the reproductive performance and in vitro sperm fertilizing ability of male mice. C57BL/6J female mice (F-0) were fed diets containing 0, 3, or 30 ppm TCB for 2 weeks before pairing with nontreated males for a 10-day breeding period. Females were continued on their treatment diet throughout mating, gestation, and lactation. Male offspring (F-1) were given the same diet as their dams throughout this study. F-1 males at 7 and 17 weeks of age were mated to nontreated B6D2-F1 female mice. Body weight, litter size, and survival indices of offspring sired by F-1 males were recorded. Sperm fertilizing ability of F-1 males at 9 and 19 weeks of age was examined in vitro using eggs collected from nontreated B6D2-F1 females. Sperm motion analysis was performed at the same time. When 7- and 17-week-old F-1 males were mated to nontreated females, no differences in fecundity, litter size, sex ratio, or survival indices among any of the treatments were observed. However, sperm fertilizing ability of 30 ppm-treated F-1 males at 19 weeks of age was less than that of the control mice. Testes weights were greater in 3-week-old, 30 ppm-treated mice.