Oral Supplementation with Branched-Chain Amino Acids Improves Transthyretin Turnover in Rats with Carbon Tetrachloride-Induced Liver Cirrhosis

Abstract

The hypothesis that dietary branched-chain amino acid (BCAA) supplementation improves the impaired protein turnover in male Donryu rats with carbon tetrachloride-induced liver cirrhosis was tested. We supplemented cirrhotic rats orally for 2 wk with BCAA solution [26.67 mg BCAA/(100 g body weight . d)], a conventional amino acid mixture [4.25 mg BCAA/(100 g body weight . d)] or saline and fed these three groups the AIN76 basal diet to have similar intakes of total energy and total nitrogen. Normal rats without liver cirrhosis were fed the basal diet similar to the above (noncirrhotic controls). After supplementation, rats were fed intravenous transthyretin (thyroxine-binding prealbumin) doubly labeled with 125I-tyramine-cellobiose and 131I. Kinetic indices including production rate of transthyretin were analyzed from plasma transthyretin disappearance curves. Tissue sites of transthyretin degradation were assayed using a trapped ligand technique by measuring 125I-tyramine-cellobiose levels. The production rate of transthyretin was significantly lower in cirrhotic rats supplemented with saline (mean 25.46 X 10(-3) . h(-1)) compared with noncirrhotic controls (45.08 X 10(-3) . h(-1)) (P < 0.05). This was corrected by supplementing cirrhotic rats with BCAA (37.05 X 10(-3) . h(-1), P < 0.05) but not with conventional amino acid mixture (22.49 X 10(-3) . h(-1)). The accelerated degradation of transthyretin in muscles of cirrhotic rats was improved by BCAA (P < 0.05). In conclusion, dietary supplementation with BCAA improves the impaired transthyretin turnover in rats with liver cirrhosis.

High Incidence of Lipid Deposition in the Liver of Rats Fed a Diet Supplemented with Branched-Chain Amino Acids under Vitamin B6 Deficiency

“…After 21 d, fat infiltration of the liver was observed via gross examination, liver weight per body weight, and hepatic triacylglycerol 5 levels in six of 12 rats fed the B6(2)BCAA(1) diet. Final body weight and food intake were significantly lower in the two B6(2) groups compared with the two B6(1) groups.…”

“…BCAAs play a role in delayed onset of muscle soreness and fatigue, and suppression of fatigue in the central nervous system (2,3). BCAAs have been also used for the prevention of hepatic encephalopathy in patients with liver cirrhosis (4,5). Recently, sport enthusiasts have created an increased demand for dietary supplements with BCAAs and have increased their consumption of BCAAs-enriched soft drinks.…”

Nocturnal branched‐chain amino acid administration improves protein metabolism in patients with liver cirrhosis: comparison with daytime administration

“…9 In cirrhotic rats as well, whole-body protein turnover is recovered by BCAA, but not by a conventional amino acid mixture. 29 Another possibility regards improved Fischer's ratio. The appropriate Fischer's ratio of 3 to 6 in culture medium, which is similar to the physiologic plasma concentration of BCAA in humans, is needed to achieve efficient synthesis and secretion of albumin by hepatic parenchymal cells.…”

Nutritional and Clinical Evaluation of a Modified Soy Protein with Covalently Bound Branched-Chain Amino Acids in Cirrhotic Sprague-Dawley Rats

“…Diet M significantly increased the levels of plasma BCAA as well as the BCAA/AAA ratio with respect to those of diet H and even more with respect to those of diet C. The difference with respect to animals on diet C was expected to be due to the lower BCAA and the higher AAA contents of the diet, producing a typical abnormal profile [24] with depressed BCAA and elevated AAA levels in plasma. A higher BCAA/AAA ratio in plasma of animals on diet M than on diet H was unexpected because the latter diet presented a ten times higher BCAA/AAA ratio with respect to the BCAA-modified protein (table 4).…”