Kaimoto Tae, Shibuya Mayumi, Nishikawa Kazutaka, Maeda Hideo
Department of Living Science, Shikoku University, Tokushima, Tokushima, Japan.
J Nutr Sci Vitaminol (Tokyo). 2013;59(1):73-8. doi: 10.3177/jnsv.59.73.
Male Wistar rats were fed four diets composed of purified 20% vitamin-free casein diet with (+) or without (-) vitamin B(6) (7.0 mg of pyridoxine HCl/kg of diet) and with (+) or without (-) branched-chain amino acids (BCAAs) of valine, leucine, and isoleucine (4.75%): B(6)(+)BCAA(-); B(6)(+)BCAA(+); B(6)(-)BCAA(-); and B(6)(-)BCAA(+) for 21 d. Among rats fed the B(6)(-)BCAA(+) diet, about a half showed lipid deposition in the liver. On the other hand, serum triacylglycerol levels in the B(6)(-)BCAA(+) group tended to be decreased. Hepatic triacylglycerol and cholesterol levels tended to increase in the B(6)(-)BCAA(+) group compared with the other three groups. Serum apolipoprotein B and apolipoprotein E (apo E) levels in the B(6)(-)BCAA(+) group were the lowest among the three groups. In contrast, hepatic apo E levels in the B(6)(-)BCAA(+) group were the highest among the three groups. High-performance liquid chromatography of pooled serum of rats with lipid deposits revealed that triacylglycerol and cholesterol levels in very low-density lipoprotein (VLDL) were decreased compared with other diet groups. These results strongly suggest that one of the mechanisms of lipid deposition in rats fed a B(6)(-)BCAA(+) diet is due to impaired secretion of VLDL.
将雄性Wistar大鼠分为四组，分别喂食由纯化的20%无维生素酪蛋白组成的四种日粮，日粮中添加（+）或不添加（-）维生素B6（7.0毫克盐酸吡哆醇/千克日粮），并添加（+）或不添加（-）缬氨酸、亮氨酸和异亮氨酸（4.75%）的支链氨基酸（BCAAs）：B6（+）BCAA（-）；B6（+）BCAA（+）；B6（-）BCAA（-）；以及B6（-）BCAA（+），持续21天。在喂食B6（-）BCAA（+）日粮的大鼠中，约一半出现肝脏脂质沉积。另一方面，B6（-）BCAA（+）组的血清三酰甘油水平有降低趋势。与其他三组相比，B6（-）BCAA（+）组的肝脏三酰甘油和胆固醇水平有升高趋势。B6（-）BCAA（+）组的血清载脂蛋白B和载脂蛋白E（apo E）水平在三组中最低。相比之下，B6（-）BCAA（+）组的肝脏apo E水平在三组中最高。对有脂质沉积的大鼠的混合血清进行高效液相色谱分析发现，与其他日粮组相比，极低密度脂蛋白（VLDL）中的三酰甘油和胆固醇水平降低。这些结果有力地表明，喂食B6（-）BCAA（+）日粮的大鼠脂质沉积的机制之一是由于VLDL分泌受损。
