ELECTRORETINAL RESPONSES ARE MODIFIED BY CHRONIC EXPOSURE TO TRICHLOROETHYLENE

Using an inhalation chamber, New Zealand albino rabbits were exposed t o 350 ppm (n = 6) and 700 ppm (n = 8) of trichloroethylene (TRI) 4 hrs /day, 4 days/week for 12 weeks. Electroretinograms (ERG) and oscillato ry potentials (OPs) were recorded weekly under mesopic conditions. Blo od samples were also collected weekly to determine the concentration o f TRI and its main metabolites. Recordings from the 350 and 700 ppm ex posed groups showed a significant (p < 0.01) increase in the amplitude of the a- and b-waves (ERG), while the amplitude of the OPs was signi ficantly (p < 0.01) decreased at 350 ppm and increased at 700 ppm. The se electroretinal changes were reversed to the baseline value within s ix weeks after the inhalation stopped. The observed variations in a-wa ve and OP amplitudes were related to plasmatic level of trichloroethan ol, while the effects on the b-wave were related to the blood level of TRI. These results confirm the neuro-ophthalmotoxicity of TRI and sup port the hypothesis that trichloroethanol is the major neurotoxic meta bolite of TRI. (C) 1994 Intox Press, Inc.