Pathways of ammonia detoxification to GLN in muscles associated with Increased consumption in the BCAA and ?-KG (cataplerosis) and prompt effects of BCAA and phenylbutyrate in subjects with liver cirrhosis or UCD. Favourable effect of BCAA on ammonia detoxification to GLN may be blunted by GLN degradation to ammonia in enterocytes and kidneys. Phen