Sanchez A, Hubbard R W
Department of Nutrition, School of Public Health, Loma Linda University, CA 92350.
Med Hypotheses. 1991 Sep;36(1):27-32. doi: 10.1016/0306-9877(91)90160-z.
The amino acid composition of the diet influences the postprandial levels of plasma amino acids along with the hormones insulin and glucagon in humans fed single test meals identical in composition except for protein source. Soy protein (hypocholesterolemic), vs. casein (hypercholesterolemic), contains a higher amount of arginine and glycine and induces an increase in postprandial arginine and glycine. Soy protein induces a low postprandial insulin/glucagon ratio in both hypercholesterolemic and normocholesterolemic subjects. Casein induces a high postprandial insulin/glucagon ratio among hypercholesterolemic subjects. Amino acids such as arginine and glycine are associated with a decrease, while lysine and branched-chain amino acids are associated with increased serum cholesterol levels. Our data are consistent with the hypothesis that the control of cholesterol by insulin and glucagon is regulated by dietary and plasma amino acids. From this hypothesis the insulin/glucagon ratio is proposed as an early metabolic index of the effect of dietary proteins on serum cholesterol levels, a risk factor and a common mechanism through which dietary and lifestyle factors influence cardiovascular disease.
在给食用成分相同（除蛋白质来源外）的单一测试餐的人体喂食时，饮食中的氨基酸组成会影响餐后血浆氨基酸水平以及胰岛素和胰高血糖素水平。大豆蛋白（具有降胆固醇作用）与酪蛋白（具有升胆固醇作用）相比，含有更多的精氨酸和甘氨酸，并能使餐后精氨酸和甘氨酸增加。大豆蛋白在高胆固醇血症和正常胆固醇血症受试者中均会导致较低的餐后胰岛素/胰高血糖素比值。酪蛋白在高胆固醇血症受试者中会导致较高的餐后胰岛素/胰高血糖素比值。精氨酸和甘氨酸等氨基酸与血清胆固醇水平降低有关，而赖氨酸和支链氨基酸则与血清胆固醇水平升高有关。我们的数据与以下假设一致，即胰岛素和胰高血糖素对胆固醇的控制受饮食和血浆氨基酸调节。基于这一假设，胰岛素/胰高血糖素比值被提议作为饮食蛋白质对血清胆固醇水平影响的早期代谢指标，血清胆固醇水平是一种风险因素，也是饮食和生活方式因素影响心血管疾病的共同机制。
