Ip C, Ip M M
J Natl Cancer Inst. 1981 Feb;66(2):291-5.
The effect of dietary fat on mammary tumor incidence, estrogen-binding capacity as related to the hormone dependency of the tumors, and circulating estrogen levels in Sprague-Dawley rats given an oral dose of 7,12-dimethylbenz[a]anthracene (DMBA) was investigated. Rats were fed diets consisting of 0.5, 5, or 20% corn oil starting at weaning and were administered 5 mg DMBA at 50 days of age. Tumor incidences were 13, 46, and 75% for the groups given 0.5, 5, and 20% fat, respectively, when the experiment was terminated 20-22 weeks later. Serum estradiol, measured at proestrus at 50 days of age and at the end of the experiment, was slightly depressed at both time points in rats fed the 0.5% fat diet but was similar in the other 2 groups. Serum estrone levels were not significantly different at either time point. Estrogen receptor levels in the tumor were the same in the groups given 5 and 20% fat but were lower in the group given 0.5% fat. No difference was detected in the progesterone receptor concentrations. Furthermore, most (approximately 70%) of the tumors in all 3 dietary groups regressed in response to ovariectomy, which suggested that dietary fat has very little influence on the estrogen dependence of the tumor. This observation suggested that fat intake does not result in any intrinsic difference in the biochemical action of estrogen.
研究了膳食脂肪对口服7,12-二甲基苯并[a]蒽（DMBA）的斯普拉格-道利大鼠乳腺肿瘤发生率、与肿瘤激素依赖性相关的雌激素结合能力以及循环雌激素水平的影响。从断奶开始，给大鼠喂食含0.5%、5%或20%玉米油的日粮，并在50日龄时给予5毫克DMBA。20-22周后实验结束时，给予0.5%、5%和20%脂肪的组肿瘤发生率分别为13%、46%和75%。在50日龄动情前期和实验结束时测量的血清雌二醇，在喂食0.5%脂肪日粮的大鼠中，这两个时间点均略有下降，但在其他两组中相似。血清雌酮水平在两个时间点均无显著差异。给予5%和20%脂肪的组肿瘤中的雌激素受体水平相同，但给予0.5%脂肪的组较低。孕酮受体浓度未检测到差异。此外，所有3个饮食组中的大多数（约70%）肿瘤在卵巢切除术后消退，这表明膳食脂肪对肿瘤的雌激素依赖性影响很小。这一观察结果表明，脂肪摄入不会导致雌激素生化作用的任何内在差异。
