Sarwar Gilani G, Nimal Ratnayake W M, Peace Robert W, Mueller Rudolf
Food Directorate, Health Canada, Banting Building (2203C), Tunney's Pasture, Ottawa, Ontario.
Br J Nutr. 2006 Mar;95(3):443-7. doi: 10.1079/bjn20051712.
Stroke-prone spontaneously hypertensive (SHRSP) rats are considered a suitable model for studying the effects of dietary and other environmental factors on human essential hypertension and haemorrhagic stroke. To investigate the suitability of a control diet for this strain of rats, we studied the effects of supplementing casein and soya protein isolate (SPI) with two sulphur amino acids (methionine and cystine) on the growth and lifespan of SHRSP rats. The source of dietary protein and the type of supplemental sulphur amino acid had significant (P < 0.05) effects on food intake and weight gain measured after 31 d of the feeding study, while only the type of supplemental sulphur amino acid had significant effects on mean survival times and the survival rates. On average, the casein groups had higher food intake and weight gain compared with the SPI groups. The methionine-supplemented groups had lower food intake but higher weight gain than the cystine-supplemented groups. Similarly, the methionine-supplemented groups had higher mean survival times and survival rates compared with the cystine-supplemented groups. The data would suggest that a control diet based on cystine-supplemented casein (as recommended for normal healthy rats by the American Institute of Nutrition), may not meet the sulphur amino acid requirements for SHRSP rats, and that the methionine-supplemented casein would be an appropriate control diet for this animal model.
易患中风的自发性高血压（SHRSP）大鼠被认为是研究饮食和其他环境因素对人类原发性高血压和出血性中风影响的合适模型。为了研究对照饮食对该品系大鼠的适用性，我们研究了用两种含硫氨基酸（蛋氨酸和胱氨酸）补充酪蛋白和大豆分离蛋白（SPI）对SHRSP大鼠生长和寿命的影响。在喂养研究31天后测量，膳食蛋白质来源和补充含硫氨基酸的类型对食物摄入量和体重增加有显著（P < 0.05）影响，而只有补充含硫氨基酸的类型对平均存活时间和存活率有显著影响。平均而言，酪蛋白组的食物摄入量和体重增加高于SPI组。补充蛋氨酸的组食物摄入量较低，但体重增加高于补充胱氨酸的组。同样，补充蛋氨酸的组与补充胱氨酸的组相比，平均存活时间和存活率更高。数据表明，基于补充胱氨酸的酪蛋白的对照饮食（如美国营养学会为正常健康大鼠推荐的）可能无法满足SHRSP大鼠对含硫氨基酸的需求，而补充蛋氨酸的酪蛋白将是该动物模型合适的对照饮食。
