FURTHER FLOW CYTOMETRIC STUDIES OF THE EFFECTS OF TRIETHYLENEMELAMINEON SOMATIC AND TESTICULAR TISSUES OF THE RAT

Exposure to the mutagen triethylenemelamine on rat bone marrow, blood, and testis was studied using flow cytometry of DAPI-stained nuclei. I ncreased coefficients of variation (CVs) of the G(1) peaks were observ ed in bone marrow and blood after both 1 d and 5 d exposures. After 5 d exposure and 7 d recovery both tissues had recovered, in some cases to significantly lower CVs. Increased CVs of the 1C peak of testis wer e observed only after 5 d exposure to the high dose with no subsequent ly observed recovery. Bone marrow cells also were stained with Hoechst 33258 and Propidium Iodide. No differences among dyes were observed i ndicating that increased CVs likely are due to DNA damage resulting fr om interactions with the mutagen rather than differences in how the dy es bind to DNA relative to mutagen binding. This study demonstrates th at differences occur among tissues in how quickly they respond and rec over from mutagen exposure. Increased CVs, cell cycle alterations, and decreased CVs after recovery are all potentially useful biomarkers of effect for laboratory and field studies in environmental toxicology. (C) 1994 Wiley-Liss, Inc.