디클로로벤지딘에 폭로된 흰쥐의 간장세포와 방광 상피세포에 형성된 DNA adducts의 32 P-postlabeling과 GC/MS-SIM에 의한 분석

Study on measurement of DNA adducts formed in liver cells and bladder epithelial cells of rats exposed dichlorobenzidine(DCB) by 32 P-postlabeling and GC/MS-SIM method

To identify and evaluate the dichlorobenzidine(DCB)-DNA adducts in liver cell and bladder epithelial cells by 32P-postlabeling and GC/MS-SIM, we orally exposed the dichlorobenzidine(20mg/kh body wt./day) to male Sprague-Dawley rats(l85 ±10g) for 14 days. Two kinds of DCB-DNA adduct(A1 and A2) were found at the same site of thin layer chromatogram of 32P-postlabeling method in liver cells and bladder epithelial cells. In liver cells, relative adduct labeling(RAL) X1012 of DCB-DNA adduct A1 were 34.1 ±3.71 and 69.9 ±5.02, that of adduct A2 were 74.1 ±10.1 and 105.1 ±10.1 on 10 and 14 days after treatment, respectively. And in bladder epithelia cells, RAL X1012 of DCB-DNA adduct A1 were 5.92 ±1.60 and 15.9 ±1.31, that of adduct A2 were 9.81 ±2.81 and 22.8 ±1.79 on 10 and 14 days after treatment, respectively. DCB metabolites formed DNA adducts were monoacetyl-dichlorobenzidine(acDCB) and diacetyl-dichlorobenzidine(di-acDCB), which was identify by gas chromatography/mass spectrometry-scan ionization mode(GC/MS-SIM), after hydrolysis of DCB-DNA adducts isolated from live cells and bladder epithelial cells. The base peak of acDCB were 252 and 294 m/z, and that of di-acDCB were 252, 294 and 336 m/z. In conclusion, the exposed DCB formed two kinds of DCB-DNA adduct, the proximate materials of that were acDCB and di-acDCB in liver and bladder epithelial cells. And the above GC/MS-SIM method was found the DCB-DNA adducts could be monitoring by gas chromatography.