摘要
目的在小麦面筋蛋白中添加赖氨酸和苏氨酸,探讨两种限制氨基酸在小麦面筋蛋白中降低大鼠血浆高同型半胱氨酸(Hcy)血症的影响。方法 32只健康Wistar大鼠随机分为4组,分别为大豆分离蛋白组(25S)、酪蛋白组(25C)、小麦面筋蛋白组(29G)、赖氨酸+苏氨酸添加组(29GLT)。各组大鼠分别给予不同饲料喂养14 d后处死,采集血液、肝脏等样品,用于测定生化、酶学指标。结果添加赖氨酸和苏氨酸可有效改善大鼠因摄入小麦面筋蛋白导致的体重、血浆中Hcy的降低,可抑制血浆S-腺苷蛋氨酸(SAM)和肝脏甜菜碱高半胱氨酸甲基转移酶(BHMT)活性的升高,但对胱硫醚β-合成酶(CBS)活性无影响。蛋氨酸含量较低的大豆分离蛋白组,血浆中同型半胱氨酸的含量并未降低。结论小麦面筋蛋白对大鼠血浆同型半胱氨酸浓度的影响可能与其氨基酸的组成特点有关。小麦面筋蛋白的高半胱氨酸和低赖氨酸及低苏氨酸的氨基酸组成是小麦面筋蛋白降低同型半胱氨酸水平的可能因素。
Objective To investigate the effect of limiting amino acid on plasma homocysteine concentration in rats by adding lysine and threonine to wheat gluten. Methods 32 Wistar rats were fed 25S, 25C, 29G and 29GLT diets with different dietary protein species for 14 days. At the end of the experiment, the rats were sacrificed, and blood and liver samples were subject to biochemical analysis. Results Body weight gain in rats fed with wheat gluten dietary was significantly lower than casein and soybean protein dietary, but the decrease in body weight gain was significantly suppressed by adding lysine and threonine. The plasma homocysteine concentration in rats fed with wheat gluten was significantly lower than casein, however the decrease in wheat gluten group was recovered to the level of 25C and 25S by lysine and threonine. Lysine and threonine also suppressed the plasma S-adenosyl methionine （SAM） activity and liver homocysteine betaine methyltransferase （BHMT） activity, but had no effect on the cystathionine beta synthase （CBS） activity. Plasma homocysteine （Hcy） content did not decrease in the soybean protein group with low methionine. Conclusion The effects of wheat gluten on plasma homocysteine concentration may depend on the contents of amino acid. The high level serine and low level lysine and threonine in wheat pluten may lead to the decrease of plasma Hcy content.
出处
《中国食品卫生杂志》
2015年第3期227-231,共5页
Chinese Journal of Food Hygiene
基金
"十二五"国家科技支撑项目(2012BAD33B01)
