Question: what are large neutral amino acids?
Answer: The LNAA include tryptophan, tyrosine, phenylalanine, and the branched-chain amino acids (BCAA; leucine, isoleucine and valine). ... For example, tryptophan uptake into brain and brain tryptophan concentrations fall within 60 min of an injection of leucine, isoleucine or valine (Carlsson and Lindqvist 1978).