SPERMATOTOXICITY OF DICHLOROACETIC ACID

The testicular toxicity of dichloroacetic acid (DCA), a disinfection b yproduct of drinking water, was evaluated in adult male rats given bot h single and multiple (up to 14 d) oral doses, Delayed spermiation and altered resorption of residual bodies were observed in rats given sin gle doses of 1500 and 3000 mg/kg; these effects persisted to varying d egrees on post-treatment days 2, 14, and 28, Delayed spermiation and f ormation of atypical residual bodies also were observed on days 2, 5, 9, and 14 in rats dosed daily with 1440, 480, 160, and 54 mg/kg, Disto rted sperm heads and acrosomes were observed in step 15 spermatids aft er 14 doses of 480 and 1440 mg/kg, Decreases in the percentage of moti le sperm occurred after 9 doses of 480 and 1440 mg/kg and 14 doses of 160 mg/kg, Increased numbers of fused epididymal sperm were observed o n days 5, 9, and 14 in rats dosed with 1440, 480, and 160 mg/kg, respe ctively; other morphologic abnormalities occurred at 160 mg/kg and hig her, On day 14, a significant decrease in epididymis weight was observ ed at 480 and 1440 mg/kg, and epididymal sperm count was decreased at 160 mg/kg and higher, These studies demonstrate that the testicular to xicity induced by DCA are similar to those produced by the analogue, d ibromoacetic acid, However, the testicular toxicity of DCA is less sev ere at equal molar concentrations, Moreover, the DCA-induced testicula r lesions occur with greater potency as the duration of dosing increas es, indicating the importance of using low-dose subchronic exposures t o assess the health risk of prevalent disinfection byproducts. (C) 199 7 Elsevier Science Inc.