title: 4-aminobutyrate-2-ketoglutarate aminotransferase (GABA-T) in human hair follicle.
abstract: GABA-T (4-aminobutyrate-2-ketoglutarate aminotransferase) has been found in human hair follicle. Kinetics experiments with hair follicle homogenate supported a ping-pong type of enzymatic mechanism. Extrapolated Km values were 1.02 mmol/l for GABA and 0.45 mmol/l for alpha-ketoglutarate. Hair follicle GABA-T activity was completely inhibited by preincubation of the samples with either 5 x 10(-8) mol/l aminooxyacetic acid or 5 x 10(-4) mol/l gamma-vinyl GABA. The radioenzymatic assay presented is both sensitive enough (only 10 hair follicles are needed for one assay) and economical, making it suitable for clinical practice. Hair follicle GABA-T activity determination could be useful in the study of GABA deficiency diseases (such as epilepsy), congenital GABA-T deficiencies or the control of GABA-T inhibitors treatment.
authors.affiliation: Department of Pharmacology and Therapeutics, University of Wales, College of Medicine, Cardiff, U.K.
authors.forename: J A
authors.initials: JA
authors.lastname: Armijo
mesh_terms: D000612:4-Aminobutyrate Transaminase / Q000032:analysis* / Q000037:antagonists & inhibitors; D000328:Adult; D000614:Aminocaproates / Q000494:pharmacology; D000625:Aminooxyacetic Acid / Q000494:pharmacology; D004796:Clinical Enzyme Tests; D006197:Hair / Q000201:enzymology*; D006801:Humans; D007700:Kinetics; D009422:Nervous System Diseases / Q000175:diagnosis; D020888:Vigabatrin; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
chemical_list: D000614:Aminocaproates; D000625:Aminooxyacetic Acid; D005680:gamma-Aminobutyric Acid; D000612:4-Aminobutyrate Transaminase; D020888:Vigabatrin