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大鼠一次注射大剂量或喂小剂量DENA都引起肝中鸟氨酸代谢平衡异常,ODC活性升高,OTA及OCT活性降低;DENA作用早期酶活性的变化是可逆的。喂小剂量DENA6周,OTA活性降低,停药后逐渐恢复;如喂含苯巴比妥饲料或继续喂亚硝胺,酶活性持续低下。注射CCI4肝中ODC活性也升高,但OTA及OCT活性未见明显下降。作者认为致癌物DENA对鸟氨酸代谢的影响有一定的特异性。三种酶的平衡异常有利于癌细胞的发生和发展。
One injection of large dose of DENA or low dose of DENA in rat all caused abnormal ornithine metabolism in the liver, increased ODC activity and decreased OTA and OCT activity. The change of enzyme activity in early stage of DENA action was reversible. Low-dose DENA 6 weeks, OTA activity decreased gradually recovered after withdrawal; such as feeding phenobarbital feed or continue to feed nitrosamines, enzyme activity continued to decline. ODC activity in CCI4-injected liver also increased, but no significant decrease in OTA and OCT activity. The authors believe that the carcinogen DENA on the ornithine metabolism has a certain specificity. Abnormal balance of the three enzymes is conducive to the occurrence and development of cancer cells.