REPRODUCTIVE END-POINTS IN GENERAL TOXICITY STUDIES - ARE THEY PREDICTIVE

The ability to use necropsy and in-life vaginal cytology data from 90- d general toxicity studies to predict the outcome of more definitive r eproductive toxicity tests was evaluated using data from 18 compounds tested by the National Toxicology Program, Sperm motility and vaginal cytology evaluations (SMVCE) were performed at the end of 90-d toxicit y studies. When these same compounds were tested in the definitive Rep roductive Assessment by Continuous Breeding (RACB) design, 13 of the 1 8 compounds were classified the same way by both tests. The different conclusions for five compounds can be explained by differences in dose used or in endpoints evaluated. We conclude that reproductive-system necropsy data from general toxicity studies can provide a valuable pre liminary indication of the likely reproductive toxicity of the compoun d under study, (C) 1998 Elsevier Science Inc.