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大鼠喂以含１５％脂肪，但是脂肪酸组成不一致的５组半合成饲料，实验期给以甲基亚硝基脲诱导结肠肿瘤，观察脂肪组成对处于增生危险的大鼠结肠粘膜的增生细胞核抗原（ＰＣＮＡ）、碱性磷酸酶活性（ＡＬＰ）、膜脂流动性、前列腺素Ｅ２（ＰＧＥ２）及细胞动力学的影响。结果表明：含饱和脂肪酸和单不饱和脂肪酸成分最少而含ｎ－６多不饱和脂肪酸（ＰＵＦＡ）成分最高的第３组，ＰＣＮＡ和ＰＩ标志的Ｓ期细胞数最多，ＡＬＰ活性较高；含ｎ－３ＰＵＦＡ比例最高的第４组，ＰＣＮＡ和ＰＩ标志的Ｓ期细胞数、ＡＬＰ活性及ＰＧＥ２含量最少，而膜脂流动性最好。结果提示，含ｎ－３ＰＵＦＡ较高比例的脂肪酸组成降低由化学物诱导的结肠癌变危险性，其机制之一可能是，通过减少结肠粘膜ＰＣＮＡ、ＰＩ标志的Ｓ期细胞数、ＡＬＰ活性、保护膜脂流动性及减少ＰＧＥ２生成等进行。
Rats were fed 5 semi-synthetic feeds containing 15% fat but inconsistent fatty acid composition. Colon tumors were induced with methyl nitrosourea during the experimental period to observe the effects of fat composition on the proliferating cell nuclear antigen in colon mucosa of rats at risk of hyperplasia. (PCNA), alkaline phosphatase activity (ALP), membrane lipid fluidity, prostaglandin E2 (PGE2) and cellular dynamics. The results showed that: In the third group containing the lowest saturated fatty acid and monounsaturated fatty acid components and having the highest n-6 polyunsaturated fatty acid (PUFA) composition, PCNA and PI markers had the highest number of S phase cells and the highest ALP activity; In group 4 with the highest proportion of -3 PUFAs, the number of S phase cells, ALP activity, and PGE2 content of PCNA and PI markers were the least, and membrane lipid fluidity was the best. The results suggest that a higher proportion of fatty acids containing n-3 PUFA may reduce the risk of colorectal cancer-induced colon cancer. One of the mechanisms may be that by decreasing the number of S phase cells, ALP activity, and protective film of PCNA and PI markers in the colonic mucosa. Lipid fluidity and reduction of PGE2 production are performed.