Determination of Platelet Monoamine Oxidase by New Continuous Spectrophotometric Method

Abstract

Summary:A simple, continuous Spectrophotometric method for the determination of tissue monoamine oxidase based on the oxidation of 2,2'-azino-di-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) using peroxidase has already been described (Ivanovic, I. & Majkic-Singh, N. (1986) Fresenius Z. Anal. Chem. 324, 307). In the present study the method is optimised for platelet monoamine oxidase assay and applied to healthy persons and schizophrenic patients. The obtained data were statistically analysed. The continuous ABTS method is sensitive, precise (CV below 6. The reference values for the activity of human platelet monoamine oxidase by the new continuous ABTS method are 25 to 42 U/g protein (x = 33.2 U/g protein, CV = 15.5%, n = 67). No differences were found between females and males, or between three age groups ranging from 21 to 52 years. The patients with chronic (n = 76) or acute (n = 17) schizophrenia had significantly lower monoamine oxidase activities compared with normal values (p < 0.005), which indicates that platelet monoamine oxidase can be a possible marker for schizophrenic diseases.

Enzymatic oxidation of substituted tryptamines catalysed by monoamine oxidase

“…For studying the kinetic of enzymatic oxidative deamination of 5-HT and isotopologues of 5-F--tryptamine, [20] Each kinetic run consisted of six measurements carried out in 1 mL quartz spectroscopic cuvettes for different concentrations of 5-HT and isotopologues of 5-F-tryptamine (from 0.03 to 0.1 mM). The quantities of enzymes MAO-A and HRP VI-A in each cuvette were 1 and 5 U/mL, respectively.…”