Developmental effects of intermittent prenatal exposure to 1,1,1-trichloroethane in the rat

The effects of daily three l-h exposures to 7000 ppm 1,1,1-trichloroethane (TCE) on physical and behavioral development were examined in Sprague-Dawle y rats exposed during the last week of gestation. A sham group was exposed to filtered air. Offspring of both groups were fostered to untreated dams. No significant group differences were detected in total maternal weight gai n or food and water consumption, but differences were observed in initial l itter characteristics, including a longer gestation period in the TCE group , a smaller number of litters delivered in the TCE group, and fewer live pu ps per litter in the TCE group. At birth, the total litter weight was less in the TCE group, but there was no significant difference in average pup we ight. Pups prenatally exposed to TCE did not differ from shams in day of ey e opening, pinnae detachment, or incisor eruption. The TCE group weighed le ss the first 2 weeks of life, was impaired in its ability to perform the in verted screen, negative geotaxis, and vertical screen tests, and had less f orelimb grip strength. Locomotor activity was reduced in the TCE group, and the ratio of brain to body weight was reduced in TCE-exposed offspring. Th ese data provide evidence for neurobehavioral teratogenicity of intermitten t prenatal exposure to high concentrations of TCE in rats. (C) 1999 Elsevie r Science Inc. All rights reserved.