Determination of semicarbazide-sensitive amine oxidase activity in human plasma by high-performance liquid...

We report here a simple and sensitive method for the measurement of semicarbazide-sensitive amine oxidase (SSAO) activity in human plasma. Benzaldehyde, generated during a 1-h incubation of plasma with benzylamine, is derivatized with the specific aldehyde reagent dimedone after prior deproteinization. Quantitation of the derivatization product is done by automated injection onto an isocratic high-performance liquid chromatographic system with fluorimetric detection. The assay shows good linearity and reproducibility (intra-assay C.V. 7%). Detection limit is 25 mU/l (= pmol/ml/min). In 51 healthy controls (age 49 +/- 13 yr, 20 males) the measured SSAO activity was 352 +/- 102 mU/l (mean +/- S.D.). A large number of samples (70-80) can easily be processed in one day by one technician.