ACUTE SPERMATOGENIC EFFECTS OF BROMOACETIC ACIDS

Chlorine and bromine can react with natural organic substances in sour ce waters to form haloacetic acids, major disinfection by-products of water chlorination. Several toxic effects including testicular damage have been attributed to the chloroacetic acids but little information is available on the bromine analogues. In this report we present the r esults of acute toxicity and acute spermatotoxicity studies of monobro moacetic acid (MBAA) and dibromoacetic acid (DBAA). In adult male rats the acute oral toxicity of MBAA was 10-fold that of DBAA (LD50 177 vs 1737 mg/kg). No reproductive-related endpoints were affected in rats given a single dose of 100 mg MBAA/kg or 14 daily doses of 25 mg MBAA/ kg/day. In rats dosed with DBAA, serum testosterone fell to 17% of con trol 2 days after a single dose of 1250 mg/kg but returned to control levels by Day 14. Marked effects on sperm motion were seen on post-tre atment Days 14 and 28. Degenerative flagellar changes in cauda sperm w ere present on Day 14 while abnormal sperm head shapes and flagellar d egeneration were observed in both caput and cauda sperm on Day 28. His topathology indicated altered spermiation at all timepoints as evidenc ed by retention of Step 19 spermatids beyond Stage VIII of the cycle o f the seminiferous epithelium. Disorganization, distortion, and degene ration of late spermatids were also observed. On Day 14 structures res embling residual bodies were rarely seen in the testis but were numero us in the epididymis. Caput sperm counts were decreased on Day 2 and c auda sperm counts were decreased on Days 14 and 28. The data indicate that DBAA is a testicular toxicant in the rat with late and elongating spermatids being particularly susceptible germinal cells. (C) 1994 So ciety of Toxicology.