Rat model of perchloroethylene-induced renal dysfunctions

To investigate whether perchloroethylene (PCE) can induce renal disturbances and to compare morphological alterations with functional data, two groups of 12 male and female Fischer-344 mature rats were treated daily with PCE (500 mg/kg body wt in corn oil, p.o.) for 4 weeks. Sex- and age-matched control groups received corn oil only. Weekly, the urinary excretion of albumin (Alb), α_2μ-globulin (α_2μ) and retinol-binding protein (RBP) was measured in 24-hr urine samples using immunoassays specific for rat proteins. N-acetylglucosaminidase (NAG) activity was measured by a colorimetric assay. Electrophoretic analysis of proteinuria included SDS-PAGE and isoelectric-focusing of Alb purified from serum and urine. Weekly histopathology comprised light and electron microscopy. In the male rat, a trend toward progressive albuminuria (up to 15 times the pair-fed controls) was oberved, together with transient increases in α_2μ and NAG; RBP showed a twofold increase at the end of treatment. Histopathology failed to demonstrate glomerular changes, whereas it displayed α_2μ accumulation and mild lesions in the S2 segment of proximal tubules. Thus, in the male rat, the selective damage to S2 was associated with “glomerular” proteinuria, the α_2μ cortical content being closely correlated with albuminuria (n = 9, r = 0.92, P < 0.001). In the female rat, only minor, although statistically significant (P < 0.05), increases were recorded for Alb, whereas urinary α_2μ reached up to four times the control values. As a whole, these findings suggest that PCE, like other hydrocarbons, selectively affects the tubular segment S2 in the rat. A competition with α_2μ for tubular uptake could explain enhanced albuminuria. Owing to the species specificity of α_2μ, caution should be exercised in extrapolating these findings to man.