Luo F Q, Lu S X
Cancer Institute, Chinese Academy of Medical Sciences, Beijing.
Zhonghua Zhong Liu Za Zhi. 1988 Jan;10(1):12-4.
The effect of copper and zinc on the metabolism of N-nitrosamine and activity of cytochrome P-450 in the liver of rats was studied. Copper and zinc enhanced obviously the activity of cytochrome P-450 in the liver. The level of cytochrome P-450 in the liver of control rats was 0.64 nmol/mg protein but that in the liver of rats treated with copper or zinc was 1.31 and 1.17 nmol/mg protein. There was a significant difference between the two groups (P less than 0.01-0.001). The activity of demethylase reflected the metabolic level of N-nitrosamine. In the control group, metabolic level of N-dimethyl-nitrosamine, N-methyl-N-butylacetonylnitrosamine and nitrosopyrrolidine was markedly higher than the copper and zinc groups. It is indicated that copper and zinc inhibit obviously the activity of demethylase, resulting in reduction of the metabolic activation of N-dimethylnitrosamine, N-methyl-N-butylacetonylnitrosamine and nitrosopyrrolidine. The role of copper and zinc in the chemical carcinogenesis is discussed.
研究了铜和锌对大鼠肝脏中N - 亚硝胺代谢及细胞色素P - 450活性的影响。铜和锌明显增强了肝脏中细胞色素P - 450的活性。对照组大鼠肝脏中细胞色素P - 450的水平为0.64 nmol/mg蛋白质，而用铜或锌处理的大鼠肝脏中该水平分别为1.31和1.17 nmol/mg蛋白质。两组之间存在显著差异（P小于0.01 - 0.001）。脱甲基酶的活性反映了N - 亚硝胺的代谢水平。在对照组中，N - 二甲基亚硝胺、N - 甲基 - N - 丁基乙酰丙酮基亚硝胺和亚硝基吡咯烷的代谢水平明显高于铜和锌处理组。表明铜和锌明显抑制脱甲基酶的活性，导致N - 二甲基亚硝胺、N - 甲基 - N - 丁基乙酰丙酮基亚硝胺和亚硝基吡咯烷的代谢活化降低。讨论了铜和锌在化学致癌作用中的作用。
