Black H S, Thornby J I, Gerguis J, Lenger W
Veterans Affairs Medical Center, Houston, TX.
Photochem Photobiol. 1992 Aug;56(2):195-9. doi: 10.1111/j.1751-1097.1992.tb02147.x.
To determine the segment along the carcinogenic continuum at which dietary lipid exerts its principal effect, six groups of 35 Skh-HR-1 hairless mice were placed on defined isocaloric diets containing either 0.75%, 12% corn oil or 12% menhaden oil as sources of omega-6 or omega-3 fatty acids, respectively. All animals received an 11 week course of UV-radiation from fluorescent sunlamps. Upon termination of UV, diets of some groups were crossed-over to either low fat, high fat, omega-6 or omega-3 fatty acid sources. The first tumor appeared at week 14. Life-table analysis of the tumor incidence curves and Wilcoxon tests of tumor multiplicity provided evidence that high corn oil diets significantly (P less than 0.01) enhance carcinogenic expression; that tumor enhancement by the omega-6 fatty acid source occurs during the post-initiation, or promotion, stage; that replacement with a low corn oil diet after UV-initiation will negate the exacerbating effect of high corn oil; and that an omega-3 fatty acid source inhibits UV-carcinogenesis even at high dietary levels, although not during the post-initiation stage.
为了确定膳食脂质在致癌连续过程中发挥主要作用的阶段，将六组每组35只的Skh-HR-1无毛小鼠置于特定的等热量饮食中，分别以0.75%、12%的玉米油或12%的鲱鱼油作为ω-6或ω-3脂肪酸的来源。所有动物接受来自荧光太阳灯的为期11周的紫外线辐射。紫外线照射结束后，一些组的饮食交叉换成低脂、高脂、ω-6或ω-3脂肪酸来源的饮食。第一例肿瘤在第14周出现。对肿瘤发生率曲线进行生命表分析以及对肿瘤多发性进行威尔科克森检验，结果表明高玉米油饮食显著（P<0.01）增强致癌表达；ω-6脂肪酸来源对肿瘤的促进作用发生在启动后或促进阶段；紫外线启动后换成低玉米油饮食可消除高玉米油的加剧作用；并且ω-3脂肪酸来源即使在高膳食水平下也能抑制紫外线致癌作用，尽管在启动后阶段不起作用。
