The significance of ammonia/gamma-aminobutyric acid (GABA) ratio for normality and liver disorders.
Cohen has illustrated that extremely high Gamma-aminobutyric acid (GABA) levels in the urine and blood and high plasma ammonia were observed for an autistic male child diagnosed with infantile autism. GABA is a major inhibitory neurotransmitter of the mammalian brain and the enzyme responsible for catabolism is GABA-Transaminase (GABA-T). Elevated levels of ammonia in the plasma results in a decrease in the efficiency for the GABA-T enzyme and this results in higher GABA concentrations after regulation in the liver. It is postulated that a link between plasma ammonia and plasma GABA exists where the concentration of GABA in the plasma is directly related to the ammonia plasma concentration. A ratio of approximately 0.30 (plasma ammonia/GABA) is a consistent finding for normal subjects and for subjects with infantile autism and liver diseases such as hepatic encephalopathy.
Cohen
Brett I
BI
ED Laboratories, S Hackensack, New Jersey 07606, USA. eds.pipeline.com
D000612:4-Aminobutyrate Transaminase / Q000378:metabolism; D000641:Ammonia / Q000378:metabolism*; D001321:Autistic Disorder / Q000209:etiology; D006801:Humans; D008099:Liver / Q000378:metabolism*; D008107:Liver Diseases / Q000378:metabolism*; D008954:Models, Biological; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D005680:gamma-Aminobutyric Acid; D000641:Ammonia; D000612:4-Aminobutyrate Transaminase