Pathways of ammonia detoxification to GLN in muscles associated with enhanced use of the BCAA and ?-KG (cataplerosis) and suggested effects of BCAA and phenylbutyrate in topics with liver cirrhosis or UCD. Constructive effect of BCAA on ammonia detoxification to GLN could be blunted by GLN degradation to ammonia in enterocytes and kidneys. Phenylbu