High incidence of lipid deposition in the liver of rats fed a diet supplemented with branched-chain amino acids under vitamin B6 deficiency

• Published in: Journal of nutritional science and vitaminology Vol. 59; no. 1; p. 73
• Main Authors: Kaimoto, Tae, Shibuya, Mayumi, Nishikawa, Kazutaka, Maeda, Hideo
• Format: Journal Article
• Language: English
• Published: Japan 2013
• Subjects: Amino Acids, Branched-Chain - adverse effects; Amino Acids, Branched-Chain - metabolism; Amino Acids, Branched-Chain - pharmacology; Animals; Apolipoproteins B - blood; Apolipoproteins E - blood; Apolipoproteins E - metabolism; Caseins - administration & dosage; Cholesterol - blood; Cholesterol - metabolism; Cholesterol, VLDL - blood; Cholesterol, VLDL - metabolism; Chromatography, High Pressure Liquid; Diet; Dietary Supplements; Fatty Liver - etiology; Fatty Liver - metabolism; Liver - drug effects; Liver - metabolism; Male; Pyridoxine - administration & dosage; Pyridoxine - metabolism; Pyridoxine - pharmacology; Rats; Rats, Wistar; Triglycerides - blood; Triglycerides - metabolism; Vitamin B 6 Deficiency - complications; Vitamin B 6 Deficiency - metabolism; Vitamin B Complex - administration & dosage; Vitamin B Complex - metabolism; Vitamin B Complex - pharmacology

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.