Renal toxicity after chronic inhalation exposure of rats to trichloroethylene.

Male Long-Evans rats were exposed to 0 (controls) or 500 ppm trichloroethylene (TRI) for 6 months, 6 h daily, and 5 days a week. The TRI metabolites trichloroethanol (TCE) in blood and trichloroacetic acid (TCA) in urine were measured. Specific parameters related to the renal damage were determined in urine [biomarker for glomerular damage: high molecular weight proteins (HMW), albumin (ALB); for proximal tubular damage: N-acetyl-β-d-glucosaminidase (NAG), low-molecular-weight-proteins (LMW)]. Significantly increased concentrations of NAG and LMW in urine of exposed rats were detected. No DNA-strand breaks in kidney cells could be detected using the comet assay, and histological examinations were performed. Histological alterations were observed in glomeruli and tubuli of exposed rats. The release of biomarkers for nephrotoxicity suggested alterations preferably in the proximal tubules of the exposed rats.