COMPARATIVE-STUDIES ON RADIATION-INDUCED MICRONUCLEI AND CHROMOSOMAL-ABERRATIONS IN V79 CELLS

Induction of micronuclei (MN) and structural chromosomal aberrations ( SCA) by physical agents such as X-rays and UV radiation has been studi ed extensively in a variety of cell lines for genotoxicity assessment. However, comparative data on the relationship between these two cytog enetic endpoints are limited. This study compares SCA and MN formation in V79 Chinese hamster lung cells treated with X-rays and UV radiatio n. Four replicate cultures of exponentially growing cells were exposed to four doses of X-rays (100-800 rads). For two replicate cultures, c ytochalasin B (3 mu g/ml) was added and cells were harvested 16 h late r far MN and nuclear division index (NDI) assessment. For the remainin g two replicate cultures, colcemid (0.025 mu g/ml) was added 16 h post -treatment and cells were harvested 2 h later for SCA and mitotic inde x (MI) analyses. This experiment was duplicated using four doses of UV radiation (100-800 mu J x 10(2)/cm(2)). In the X-ray experiment, gene rally, a decrease in the NDI and MI was noted with increasing dose. Al so, there was a dear dose-related increase in percent micronucleated b inucleated (MNBN) and aberrant cells. A similar dose response, but wit h lower frequencies, was observed in the UV radiation treatment. These data suggest a good correlation between chromosome damage as measured by percent MNBN and aberrant cells and cytotoxicity as measured by ND I and MI.