权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Regulation of plasma cholesterol level by sulfur-containing amino acids

含硫氨基酸调节血浆胆固醇水平

基本信息

批准号：
63560078
负责人：
SUGIYAMA Kimio
金额：
$ 1.28万
依托单位：
Shizuoka University, Faculty of Agriculture
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1988
资助国家：
日本
起止时间：
1988 至 1989
项目状态：
已结题

项目摘要

1. The effects of dietary sulfur-containing amino acids (methionine and cystine) on plasma cholesterol levels were investigated with rats fed cholesterol-free and cholesterol-enriched diets. It was found that the effects of sulfur-containing amino acids on plasma cholesterol levels mainly differ depending on kinds and amounts of sulfur amino acids, dietary protein level, and presence or absence of exogenous cholesterol.2. The mechanisms by which dietary taurine and glycine lower plasma cholesterol levels were investigated. The effect of taurine, but not glycine, could be accounted for by stimulation of fecal bile acid excretion. It was suggested that the influence of glycine on methyl-group metabolism might participate in the plasma cholesterol-lowering effect of glycine.3. The effects of methyl-group acceptors such as glycine, guanidinoacetic acid and nicotinamide on plasma cholesterol levels, PE N-methyltransferase and PC biosynthesis were investigated. The methyl-group acceptors improved methionine-induced hypercholesterolemia and depressed PE N-methyltransferse activity and incorporating of methyl-group of methionine. These findings indicated that the plasma cholesterol-elevating effect of methionine is due stimulation of PC biosynthesis via PE N-methylation pathway.4. The effects of dietary methionine and protein source an plasma cholesterol levels were investigated in relation to hepatic free amino acid patterns. A significant correlation was found between plasma cholesterol levels and hepatic free ethanolamine levels. The results suggested that hepatic free ethanolamine reflects the influence of dietary methionine level on the synthesis and metabolism of phospholipid in the liver and on the plasma cholesterol level.

1. 通过喂食无胆固醇和富含胆固醇的饮食的大鼠，研究了饮食中的含硫氨基酸（蛋氨酸和胱氨酸）对血浆胆固醇水平的影响。研究发现，含硫氨基酸对血浆胆固醇水平的影响主要取决于含硫氨基酸的种类和含量、膳食蛋白质水平以及是否存在外源性胆固醇。2．研究了膳食牛磺酸和甘氨酸降低血浆胆固醇水平的机制。牛磺酸而非甘氨酸的作用可以通过刺激粪便胆汁酸排泄来解释。提示甘氨酸降低血浆胆固醇的作用可能与甘氨酸对甲基代谢的影响有关。 3．研究了甘氨酸、胍基乙酸和烟酰胺等甲基受体对血浆胆固醇水平、PE N-甲基转移酶和 PC 生物合成的影响。甲基受体改善了蛋氨酸诱导的高胆固醇血症，并降低了PE N-甲基转移酶活性和蛋氨酸甲基的掺入。这些结果表明，蛋氨酸升高血浆胆固醇的作用是通过PE N-甲基化途径刺激PC生物合成所致。4．研究了膳食蛋氨酸和蛋白质来源对血浆胆固醇水平的影响与肝游离氨基酸模式的关系。血浆胆固醇水平和肝游离乙醇胺水平之间存在显着相关性。结果提示，肝游离乙醇胺反映了膳食蛋氨酸水平对肝脏磷脂合成代谢以及血浆胆固醇水平的影响。