Glutamyl transferase y-GT

Sample material Serum, EDTA or heparin plasma. 

Drug or metabolite in sample Concentration up to which no interference occurred [mg/1] Concentration usually appearing in serum [mg/1] Interference, direction [mg/1] Clinically relevant 

References E145, E221, E270, E282, E351, E375. 

Statistical data from evaluations - Intra-assay imprecision 

Straight line equation Correlation coefficient Number of samples compared Comparative method References 

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Activities of glutamate-pyruvate transaminase (SGPT, GPT) (EC 2.6.1.2), L-y -glutamyl-transferase (y-GT) (EC 2.3.2.2) and level of triglycerides (TG) in serum, as well as levels of glutathione (GSH) and malondialdehyde (MDA) in the liver were determined. 

In the assay described here cells are permeablized using a detergent-based lysis method. Care must be taken to inhibit the membrane-bound enzyme, y glutamyl-transferase (y-GT), which metabolizes glutathione released from the cell (12). This is achieved by the use of an acidified lysis buffer (8). The lysate is then assayed for total protein and glutathione content. 

Gamma-glutamyl-transferase activity was determined according to "Monotest 10 y-GT neu" from Boehringer-Mannheim. 

GSH enables the transport of amino acids and low-molecular-weight peptides through cell membranes by transfer of y-L-glutamyl residues to amino acids and certain dipeptides [catalyzed by y-glutamyl transpeptidase (y-glutamyl transferase, abbreviation y-GT, EC 2.3.2,2)]. The detoxification of electrophilic xenobi-otic substances by elimination as - mostly water-soluble, non-toxic - 5-substituted acetylcysteine derivatives (so-called mercapturic acids) is initiated by glutathione S-transferases (abbreviation GST, EC 2.5.1.18). For further information on the biochemistry, see Lit.. ... 

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