Impairment of male rat reproductive function in F1 offspring from dams exposed to 2-bromopropane during gestation and lactation.

The toxic effects of 2-bromopropane (2-BP) on the reproductive tracts of male F1 offspring from dams exposed to 2-BP during gestation and lactation were investigated. Ten pregnant (sperm-positive) Sprague-Dawley rats per group were exposed sc to 2-BP at 135, 405, and 1215 mg/kg/day from gestation day (GD) 6 to postnatal day (PND) 20. 2-BP decreased the proportion of dams littering at the two highest doses. At the highest dose, the rate of delivery and surviving pups were significantly lower than in the controls (P < or = 0.05). The relative weights of testes vs. brain were significantly lower than the controls (P < or = 0.05) on PND 33 and 63 at 405 mg/kg/day, and on PND 90 at 1215 mg/kg/day in the F1 rats. Seminiferous tubule atrophy, germ cell loss, and increased Leydig cell proliferation were observed at the highest dose by histopathologic examination. Female offspring has a decrease in all follicle types at the high dose. These results suggest that gestational and lactational exposure to 2-BP at a high maternally toxic dose impairs the development of the reproductive organs of the offspring.