METABOLIC AND REGULATORY EFFECTS OF BRANCHED-CHAIN AMINO-ACID SUPPLEMENTATION

This review specifically examines the various roles of the supplementa tion of branched chain amino acids (BCAA) in general and leucine in pa rticular. These amino acids have been shown to have variable effects u nder different experimental dietary conditions. The branched chain ami no acids have a special role in nitrogen metabolism both in the fastin g state when they provide the brain with an energy source and after fe eding when they are extracted predominantly by muscle to provide impor tant source of energy as well as nitrogen, Supplementation of leucine also affects tryptophan niacin pathway which further depends upon the dietary intake of vitamin B-6. Moreover, leucine supplementation with low protein diet has been shown to be protein catabolic while with ade quate protein diet it has been shown to promote growth. Branched chain amino adds have also been used in the treatment oi certain protein ca tabolic states. Besides, leucine supplementation has also been shown t o affect the secretion of prolactin and insulin. These data suggest th at BCAA not only act as a precursors for several metabolic reactions b ut are also important biochemical regulators.