Evidence for the lack of base-change and small-deletion mutation inductionby trichloroethylene in lacZ transgenic mice

Trichloroethylene (TCE) is a widely used industrial solvent employed mainly for degreasing and cold-cleaning metal parts. It is also used for dry clea ning, and in the production of a number of chemical products. it has been s hown to induce liver and lung tumors in rodents, and have a variety of posi tive and negative results using in vitro and in vivo mutagenicity tests. In order to assist in the interpretation of the mechanism of carcinogenicity, TCE was tested for the ability to induce gene mutations and small deletion s using the lacZ transgenic mouse model (Muta(TM)Mouse). Male and female an imals were exposed by inhalation to 0, 203, 1153, and 3141 ppm TCE, 6 h per day for 12 days. 14 and 60 days following the last expo sure, animals were sacrificed and the mutation Frequency in bone marrow, kidney, spleen, live r, lung, and testicular germ cells determined. The results of this study in dicate that TCE did not induce base-change or small-deletion mutations as d etected in this essay in any of the tissues examined. Published 1999 Wiley- Liss, Inc.