SPERMATID MICRONUCLEUS ANALYSES OF TRICHLOROETHYLENE AND CHLORAL HYDRATE EFFECTS IN MICE

Mice were exposed by inhalation to trichloroethylene (TCE) or by i.p. injection to the TCE metabolite, chloral hydrate (CH). Early spermatid s were analyzed for micronucleus (MN) frequency and the presence or ab sence of kinetochore(s) using fluorochrome-labeled anti-kinetochore an tibodies. It was determined that 5 consecutive days of exposure to 5, 50 or 500 ppm TCE during preleptotene through early pachytene stages o f meiotic cell development do not result in increased frequencies of s permatid MN, CH at 41, 83 or 165 mg/kg was positive for spermatid MN i nduction when treatments corresponded to spermatogonial stem cell or p releptotene spermatocyte stages of development; negative results were obtained after treatments of leptotene-zygotene or diakinesis-metaphas e stages. The significantly increased levels of MN observed were invar iably of the kinetochore-negative type.