致(促)癌物对大鼠肝、腺胃和直肠鸟氨酸脱羧酶的诱导

INDUCTION OF ORNITHINE DECARBOXYLASE (ODC) IN RAT LIVER, GLANDULAR STOMACH AND COLON BY CARCINOGENS OR TUMOR PROMOTERS

用大鼠作体内急性实验观察各种致(促)癌物对肝、腺胃及直肠等组织鸟氨酸脱羧酶(ODC)活性的诱导作用。结果发现:注射亚硝氨类致癌物[二乙基亚硝胺(DENA)及二甲基亚硝胺(DMNA)]24/小时可使肝中ODC活性分别升高12倍和3倍。促癌物苯巴比妥和巴豆油分别诱导4.5小时后,肝中ODC活性分别上升8.5倍和54倍;甲基胆蒽诱导24/小时后,肝中此酶活性上升6倍。分别灌入胃癌致癌物N—甲基—N—硝基—N—亚硝基胍(MNNG)或4—硝基—1—氧化喹啉(4—NQO)24小时后,大鼠腺胃粘膜ODC活性分别升高34倍和47倍。以促癌物脱氧胆酸钠保留灌肠3.5小时后,结肠和直肠粘膜ODC活性可诱导增高38倍。ODC与细胞增生及癌变关系密切,用致(促)癌物对ODC的诱导方法比较特异,可靠和迅速,因此可以考虑作为对肝、腺胃及结肠等消化道致(促)癌物检测筛选的生化指标。

The induction of ODC activity in rat liver, glandular stomachand colon by carcinogens or tumor promoters in vivo was investigated. It was found that the hepatic ODC activity was elevated to 12 and 3 folds of the control value 24h afte-er treatment of hepatic carcinongen DENA and DMNA, respectively. The promoters phen-obarbital or croton oil induced 8.5 or 54 folds increase in the hepatic enzyme, respectively, 4.5h after their administration, and hepatic ODC activity was elevated to 6 folds of control value 24h after injection of 3- methylcholanthrene. The gastric carcinogens MNNG and 4-NQO induced 34 to 47 folds incerase in ODC activity in the mucosa of glandular stomach 24h after stomach intubation. The promoter, sodium deoxycholate, induced 38 folds increase of the enzyme activity in mucosa of colon 3.5h after intrarectal instillation. It was suggested that the induction of ODC may be an useful criterium for the detection of the potential carcinogen or promoter, because it is specific, fast and reliable.