Student Research: Mark P. Burry

, , 2001
Faculty Advisor: Lucio G. Costa

Neurodevelopmental Toxicity of Toluene


Abstract

Toluene is a widely used industrial solvent that is found in a variety of consumer products from paint thinners to rubber cement. In recent years toluene has become increasingly used as a sniffing agent due to its cheap price and availability. Case reports of humans exposed to high doses of toluene idicate that the central nervous system is a primary target. Additional reports reveal that children born to women who abuse toluene during pregnancy present growth retardation, microencephaly, and facial characteristics that are similar to newborns with fetal alcohol syndrome. The mechanisms of toluene's developmental neurotoxicity are unknown. In an effort to characterize the effects of toluene on neurodevelopment, Sprague-Dawley rats were treated with 250, 500, and 750 mg/kg toluene i.p. in corn oil from postnatal day 4 to postnatal day 10. The endpoints measured included body and brain weights, and levels of neuron specific enolase and glial fibrillary acidic protein in the brain. The results of the in vivo study indicated that the brain weights of the treated animals decreased in a dose-dependent manner, however, so did the total body weight, thus resulting in no changes in brain to body weight ratios (i.e., no selective microencephaly). Immunoblot analysis of whole brain homogenates revealed no change in NSE levels and a significant decrease in GFAP levels up to 30% of the controls.