© 1995 Oxford University Press
research-article |
Assessment of the Reproductive Toxicity of a Complex Mixture of 25 Groundwater Contaminants in Mice and Rats11
*National Toxicology Program, National Institute of Environmental Health Sciences P. O. Box 12233, MD#3-03, Research Triangle Park, North Carolina 27709
Research Triangle Institute P. O. Box 12194, Research Triangle Park, North Carolina 27709
Environmental Health Research and Testing, Incorporated 2514 Regency Road, Lexington, Kentucky 40503
Received August 18, 1992; accepted October 10, 1994
The potential reproductive toxicity of a mixture of 25 chemicals (MIX) formulated to simulate contaminated groundwater supplies near hazardous waste dumps was evaluated in CD-1 Swiss mice and Sprague-Dawley rats using the reproductive assessment by continuous breeding protocol. Male and female mice and rats were exposed to MIX in the drinking water at concentrations of 1, 5, and 10% of a technically achievable stock solution. For mice, body weight and feed consumption were not affected by MIX but water consumption was decreased for both the 5 and 10% MIX groups in both F0 and F1 animals. For F0 mice, the number of live pups/litter was decreased at 10% MIX and the number of females/litter was decreased 10 and 17% at the mid and high MIX dose, respectively. Vaginal cytology was normal, as were testis weight and testicular spermatid head count. For F1 mice, fertility was unaffected, but there was a decreased number of female pups/litter (19%) and a decreased adjusted live pup weight at 10% MIX. At necropsy, cauda epididymal sperm concentration and spermatid head count were reduced (20%) in the presence of normal testis, epididymis, prostate, seminal vesicle, liver, and kidney/adrenal weight. Female estrous cyclicity was altered at 5 and 10% MIX with nor mal kidney/adrenal, uterus, and ovary%oviduct weight. For rats, F0 body weight and feed consumption were not affected by MIX but water consumption was decreased 10, 30, and 40% in the low-, medium-, and high-dose MIX groups, respectively, and 39% in the high-dose MIX F animals. Rat fertility was normal but there was a decreased number of male pups/litter (11%) and a decreased live pup weight (6%) at 10% MIX. Male and female.