title: A more sensitive automated method for determination of ornithine carbamoyltransferase activity in human serum.
abstract: Ornithine carbamoyltransferase (EC 2.1.3.3) activity is a sensitive, specific indicator of hepatocellular injury. This paper describes development of an improved automated procedure for measurement of this activity. Triethanolamine-ethylenediaminetetraacetate is used as a buffer, and activity is determined by measuring the concentration of the product, citrulline. Kinetic studies have been performed to determine optimal pH and L-ornithine and carbamoyl phosphate concentrations. Recovery of citrulline was studied. The upper limit of normal obtained in a study of 106 blood-bank donors was 6 U/liter. The automated procedure developed as a result of these studies, in which optimal assay conditions are used, produces a threefold increase in sensitivity and permits use of a sample volume of 1 ml.
mesh_terms: D000328:Adult; D001322:Autoanalysis; D002021:Buffers; D002221:Carbamyl Phosphate; D004796:Clinical Enzyme Tests; D004492:Edetic Acid; D004983:Ethanolamines; D005069:Evaluation Studies as Topic; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008107:Liver Diseases / Q000175:diagnosis; D009952:Ornithine; D009954:Ornithine Carbamoyltransferase / Q000097:blood*
chemical_list: D002021:Buffers; D004983:Ethanolamines; D002221:Carbamyl Phosphate; D004492:Edetic Acid; D009952:Ornithine; D009954:Ornithine Carbamoyltransferase