Initial and residual toxicity following acute exposure of developing male rats to dibromochloropropane

Male Fischer 344 rats were given a single, sc injection of 1,2-dibromo-3-chloropropane (DBCP) at 6 or 25 days of age. One group of treated animals was killed 1 to 3 days afterward to compare the dose and time relationships of the acute toxic response of neonatal and weanling male rats to DBCP and another group at approximate sexual maturity (approximately 120 days of age) to detect residual toxic effects resulting from acute exposure. The 6-day-old rats were more susceptible than the 25-day-old rats to the acute toxic effects of DBCP, as characterized by reduced 48-hr survival, renal dysfunction, and renal and hepatic necrosis over the dose range of 80 to 320 mg/kg. The lowest dose tested, 20 mg/kg, and all higher doses reduced subsequent body and gonadal weight gains, and caused hypospermatogenesis or seminiferous tubular atrophy in animals exposed at 6 days of age and killed at sexual maturity. Similar effects were observed in animals exposed at 25 days of age, except that doses of 160 mg/kg or greater were required to produce residual toxic effects. These data indicate enhanced susceptibility of neonatal male rats to the gonadotoxic effects of dibromochloropropane, including the possibility of apparent irreversible injury caused by acute exposure.