DIETARY SOYBEAN ISOLATE AND METHIONINE SUPPLEMENTATION AFFECT MAMMARY-TUMOR PROGRESSION IN RATS
DIETARY SOYBEAN ISOLATE AND METHIONINE SUPPLEMENTATION AFFECT MAMMARY-TUMOR PROGRESSION IN RATS
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DOI：
10.1093/jn/121.10.1693
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发表时间：
1991-10-01
影响因子：
4.2
通讯作者：
BLAIR, WH
中科院分区：
文献类型：
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作者：
HAWRYLEWICZ, EJ;HUANG, HH;BLAIR, WH
研究饲喂大豆分离蛋白（SBP）饲粮或大豆分离蛋白饲粮中添加0.7% dl -蛋氨酸（SBP+Met）对乳腺肿瘤进展的影响。Sprague-Dawley雌性大鼠在断奶后饲喂20%酪蛋白（CAS）饲粮中添加0.3% dl -蛋氨酸（AIN-76），并于7周龄通过颈静脉注射n -亚硝基甲基脲（NMU， 40 mg/kg体重）。NMU治疗5周后，将动物分为3个等能、等蛋白饮食组：CAS（25只大鼠）；SBP（26只大鼠）和SBP+Met（25只大鼠）。CAS组、SBP+Met组和SBP饮食组在NMU治疗后8、9和13周首次可触及乳腺肿瘤，平均潜伏期分别为13.30 +/- 1.23、16.70 +/- 1.32和17.82 +/- 1.28周。CAS组肿瘤发生率为80%，而SBP组为42.3% （P = 0.01）。补充蛋氨酸使肿瘤发病率增加到64%。与SBP+Met组和SBP组相比，CAS组肿瘤总数和总重量均大于SBP组：41个肿瘤vs. 28个或21个肿瘤，97.28 g vs. 27.87或32.46 g。这些数据表明，在致癌物暴露后5周饲喂低蛋氨酸含量的SBP饮食可显著抑制乳腺肿瘤的进展。蛋氨酸的补充增加了肿瘤动物的数量，但没有增加平均肿瘤重量。
The effect of feeding soybean protein isolate (SBP) diet or soybean protein isolate diet supplemented with 0.7% DL-methionine (SBP+Met) on mammary tumor progression was investigated. Sprague-Dawley female rats were fed from weaning a 20% casein (CAS) diet supplemented with 0.3% DL-methionine (AIN-76) and injected via jugular vein with N-nitrosomethylurea (NMU, 40 mg/kg body weight) at 7 wk of age. Five weeks after NMU treatment, animals were divided into the three isoenergetic, isoprotein diet groups: CAS (25 rats); SBP (26 rats) and SBP+Met (25 rats). First palpable mammary tumors were evident 8, 9 and 13 wk and the mean latency period was 13.30 +/- 1.23, 16.70 +/- 1.32 and 17.82 +/- 1.28 wk after NMU treatment in the CAS, SBP+Met and SBP diet groups, respectively. Tumor incidence was 80% in the CAS group compared with 42.3% in the SBP group (P = 0.01). Methionine supplementation increased tumor incidence to 64%. Total number and total weight of tumors was greater in the CAS group compared with either SBP+Met or SBP groups: 41 vs. 28 or 21 tumors and 97.28 g vs. 27.87 or 32.46 g, respectively. These data indicate that SBP diet, low in methionine content, fed 5 wk after carcinogen exposure significantly repressed mammary tumor progression. Methionine supplementation increased the number of animals with tumors but not the mean tumor weight.