A radiochemical-high-performance liquid chromatographic assay for urate oxidase in human plasma.
Polyethylene glycol-modified urate oxidase (PEG-uricase) holds promise as a hypouricemic agent for treating gout and as an adjunct to cytolytic therapy of hematologic malignancies. Spectrophotometric assays of urate oxidase are not sensitive enough for pharmacokinetic evaluation of PEG-uricase in clinical trials. We have therefore developed a more sensitive radiochemical-HPLC assay for urate oxidase activity in untreated plasma, in which 14C in urate and in the reaction product, allantoin, is monitored in the uv detector effluent with a flow-through scintillation counter. The assay is linear with amount of enzyme and time of incubation and can detect less than 1 x 10(-5) U/ml uricase in plasma. The assay accounts for plasma samples of widely differing urate content.
Greenberg
M L
ML
Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710.
Hershfield
M S
MS
D002247:Carbon Isotopes; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D006801:Humans; D011092:Polyethylene Glycols / Q000494:pharmacology; D014503:Urate Oxidase / Q000097:blood*
D002247:Carbon Isotopes; D011092:Polyethylene Glycols; D014503:Urate Oxidase