TOLUENE ABUSE EMBRYOPATHY - LONGITUDINAL NEURODEVELOPMENTAL EFFECTS OF PRENATAL EXPOSURE TO TOLUENE IN RATS

To determine the longitudinal effects of prenatal exposure to toluene in rats, dams received daily gavage doses of toluene diluted in corn o il on Days 6 through 19 of gestation, whereas control dams received co rn oil, Litters were evaluated either on Gestational Day 19, Postnatal Day 10, or Postnatal Day 21; morphometric analysis of brain and measu rements of brain DNA, cholesterol, and protein were made, Prenatal tol uene exposure produced growth retarded fetuses with smaller brain and caudate-putamen volumes, fewer forebrain cell nuclei (DNA), and a redu ction in both hindbrain cell size (protein/DNA) and myelination per ce ll (cholesterol/DNA), Postnatal catch-up growth occurred in the prenat ally toluene-exposed pups, and by Postnatal Day 21 these differences h ad resolved. However, on Postnatal Day 21, a significant reduction in forebrain myelination/cell was present in the prenatally toluene-expos ed pups, Therefore, whereas the effects of toluene administered prior to the time of the brain growth spurt were, for the most part, reversi ble, these exposures resulted in reduced forebrain myelination that ma y be permanent. (C) 1998 Elsevier Science Inc.