Okawa Hiroshi, Morita Tatsuya, Sugiyama Kimio
Department of Applied Biological Chemistry, Faculty of Agriculture, Shizuoka University, Japan.
Biosci Biotechnol Biochem. 2007 Jan;71(1):91-7. doi: 10.1271/bbb.60390. Epub 2007 Jan 7.
The effect of dietary supplementation with cysteine on the plasma homocysteine concentration was investigated in rats fed on 10% casein (10C) and 30% casein (30C) diets. The 10C diet significantly increased the plasma homocysteine concentration as compared with the 30C diet. The hyperhomocysteinemia induced by the 10C diet was significantly suppressed by cysteine supplementation even at a 0.3% level, whereas cysteine did not decrease the plasma homocysteine concentration when added to the 30C diet. In contrast, 0.3% methionine supplementation of the 10C diet tended to increase the plasma homocysteine concentration. Cysteine supplementation to rats fed on the 10C diet did not alter the plasma cysteine concentration and the hepatic activities of cystathionine beta-synthase and betaine:homocysteine S-methyltransferase, whereas it significantly decreased the hepatic concentrations of S-adenosylmethionine and betaine. These results suggest that cysteine supplementation might be effective for suppressing the hyperhomocysteinemia induced by a low-protein diet.
在以10%酪蛋白（10C）和30%酪蛋白（30C）日粮喂养的大鼠中，研究了日粮补充半胱氨酸对血浆同型半胱氨酸浓度的影响。与30C日粮相比，10C日粮显著提高了血浆同型半胱氨酸浓度。即使添加0.3%水平的半胱氨酸，10C日粮诱导的高同型半胱氨酸血症也被显著抑制，而当添加到30C日粮中时，半胱氨酸并没有降低血浆同型半胱氨酸浓度。相反，在10C日粮中添加0.3%的蛋氨酸倾向于提高血浆同型半胱氨酸浓度。给以10C日粮喂养的大鼠补充半胱氨酸，并没有改变血浆半胱氨酸浓度以及胱硫醚β-合酶和甜菜碱：同型半胱氨酸S-甲基转移酶的肝脏活性，然而它显著降低了肝脏中S-腺苷甲硫氨酸和甜菜碱的浓度。这些结果表明，补充半胱氨酸可能对抑制低蛋白饮食诱导的高同型半胱氨酸血症有效
