Clinton S K, Alster J M, Imrey P B, Simon J, Visek W J
Department of Internal Medicine, College of Medicine, University of Illinois, Urbana.
J Nutr. 1988 Dec;118(12):1577-85. doi: 10.1093/jn/118.12.1577.
A 3 X 3 factorial experiment was conducted to examine the effects of dietary protein (8, 16 or 32% of energy from casein) and dietary fat (12, 24 or 48% of energy from corn oil) on the promotion phase of 7,12-dimethylbenz(a)anthracene (DMBA)-induced breast carcinogenesis in rats. A purified diet with protein and fat supplying 16 and 24% of energy, respectively, was fed to 360 rats. After 4 wk each rat received DMBA (20 mg/kg) via gastric intubation. Forty rats were then randomly assigned to each of the nine dietary treatments for 28 wk. We observed no effects of protein or interactions between protein and fat on mammary tumorigenesis. At necropsy, rats fed diets containing 12, 24 and 48% of energy from corn oil following DMBA administration showed tumor prevalences of 53, 60 and 70% with 109, 127 and 140 total tumors, respectively. Linear logistic statistical modeling indicated that each doubling of dietary fat concentration multiplied the odds of finding a tumor of any histologic type at necropsy by 1.52. Dietary fat had no significant effects on the prevalence of adenomas or fibroadenomas, whereas those fed corn oil at 12, 24 and 48% of dietary energy showed adenocarcinoma prevalences of 34, 41 and 52% with total adenocarcinoma counts of 66, 75 and 96, respectively. Our results suggest that increasing dietary fat enhanced the promotion of DMBA-induced breast carcinogenesis over a wide range of protein intake.
进行了一项3×3析因实验，以研究膳食蛋白质（来自酪蛋白的能量占8%、16%或32%）和膳食脂肪（来自玉米油的能量占12%、24%或48%）对7,12-二甲基苯并(a)蒽（DMBA）诱导的大鼠乳腺癌发生促进阶段的影响。将蛋白质和脂肪分别提供16%和24%能量的纯化饮食喂给360只大鼠。4周后，每只大鼠经胃插管给予DMBA（20 mg/kg）。然后将40只大鼠随机分配到9种膳食处理组中的每一组，持续28周。我们观察到蛋白质或蛋白质与脂肪之间的相互作用对乳腺肿瘤发生没有影响。尸检时，在给予DMBA后，喂食含12%、24%和48%玉米油能量饮食的大鼠，肿瘤发生率分别为53%、60%和70%，肿瘤总数分别为109个、127个和140个。线性逻辑统计模型表明，膳食脂肪浓度每增加一倍，尸检时发现任何组织学类型肿瘤的几率就会乘以1.52。膳食脂肪对腺瘤或纤维腺瘤的发生率没有显著影响，而喂食含12%、24%和48%膳食能量玉米油的大鼠，腺癌发生率分别为34%、41%和52%，腺癌总数分别为66个、75个和96个。我们的结果表明，在广泛的蛋白质摄入量范围内，增加膳食脂肪会增强DMBA诱导的乳腺癌发生的促进作用。
