Plasma Levels Of Branched-chain Amino Acids Research Articles

Effect of a branched chain amino acid-enriched nutritional product on the pathophysiology of the liver and nutritional state of patients with liver cirrhosis.

A new nutritional product (SF-1008C) containing a high proportion of branched chain amino acids (BCAA) and low proportion of aromatic amino acids (AAA) and methionine was tested to see its effect on the impaired protein metabolism and abnormal nutritional state frequently observed in patients with advanced liver cirrhosis. A sharp increase in plasma BCAA levels and fall of AAA and methionine levels were found following the administration of an SF-1008C-supplemented diet to healthy controls and cirrhotic patients, which the BCAA levels increased only slightly following an isocaloric control diet. Blood ammonia levels increased within the normal range transiently following the diets. The SF-1008C-supplemented diet was given for 2 weeks to cirrhotic patients with histories of hepatic encephalopathy, who were taking a low-protein diet because of hyperammonemia. Serum prealbumin levels, nitrogen balance, molar ratio of plasma BCAA/phenylalanine and tyrosine, the number connection test and electroencephalograms improved during the period of the experimental diet. The results, therefore, indicate that a BCAA-supplemented diet is well tolerated by patients with advanced cirrhosis and useful for treatment of impaired protein metabolism. Furthermore, this product is beneficial in preventing hepatic encephalopathy in cirrhotics.

Evaluation of an Infusion Solution Enriched with Branched Chain Amino Acid in Parenteral Nutrition of Rats

Nutritional effects of an infusion solution enriched with branched chain amino acids (BCAAs) were investigated with young adult rats. Continuous infusion through a central venous cannula was carried out for 7 days with three kinds of solutions: 1) 21.8% glucose (S-1); 2) 18.6% glucose plus 2.50% amino acids based on human milk pattern (S-2), and 3) 18.6% glucose plus 2.58% amino acids enriched with BCAAs (S-3). Rats received daily 50 ml of the solution, containing 45 kcal and 200 mg N in S-2 and S-3. The body weights of rats in the S-2 and S-3 groups were only slightly reduced, while those of the S-1 group were extremely reduced. The rats were in positive nitrogen balance in the S-2 and S-3 groups on days 2-7. Its value was somewhat, but not significantly, larger in the S-3 group than in the S-2 group. The plasma BCAA levels determined 15 minutes after the end of infusion were higher in the S-3 group than in the S-2 group, but there was no significant difference except for the leucine level. The urinary levels of creatinine and 3-methylhistidine, the plasma levels of urea and glucose, and liver lipid content were similar in the S-2 and S-3 groups. The plasma albumin level was somewhat higher in the S-3 group than in the S-2 group. The present data suggest that an infusion solution enriched with BCAAs served to maintain the normal rats in desirable nutritional status.

RESTORATION OF NORMAL LIPID AND AMINOACID METABOLISM IN DIABETIC PATIENTS TREATED WITH A PORTABLE INSULIN-INFUSION PUMP

To determine whether abnormalities of lipid and aminoacid metabolism observed in diabetes are corrected when plasma-glucose levels are restored to normal, eight insulin-dependent diabetics were treated for 7-14 days with a portable infusion pump which delivers insulin subcutaneously in basal (between-meal) doses with pulse-dose increments before meals. Mean plasma-glucose (206±24 mg/dl during conventional insulin treatment) fell to 89±3 mg/dl at day 7 and 84±2 mg/dl at day 14 of pump treatment; glycosuria was eliminated. Plasma cholesterol, triglycerides, and free fatty acids were elevated during conventional insulin treatment but fell to normal after 7 days of pump treatment. Plasma-levels of branched-chain aminoacids were 50-60% above control levels during conventional treatment but fell to normal after 7 days of pump therapy. Aminoacids were reduced from their high postprandial levels to normal values after insulinpump treatment. In addition to restoring plasma-glucose to normal, treatment of diabetes with a portable insulin-infusion system results in restoration of normal lipid and aminoacid metabolism. Long-term use of this system may determine whether metabolic changes resulting from insulin lack cause the complications of diabetes.