engleski

EVALUATION OF METHOD FOR DETERMINATION OF PROOXIDATIVE SPECIES CONCENTRATION

Oxidative status represents balance betveen concentration of oxidants and antioxidative defence mechanisams in human body. Disturbance of this balance may be caused by excess of oxidans production or by decrease in antioxidant capacity, which results in a condition known as an oxidative stress. Oxidative stress is in corelation to almost every pathological and degenerative proces, beeing either the cause or direct consecvence. A key to accurate assesment of prooxidative status is an ability of meassuring exact prooxidative species concentration. Aim of this study is an assesment of method for determination of prooxidative species, based on Fenton chemistry. In the presence of lipoperoxides and hidrogen peroxide, Fe2+ produces hidroperoxyl radical, which turns N, N-dimethyl-p-phenylenediamine (DMPD) into fairly long lived coloured radical cation. Intensity of colour is proporrtional to prooxidative species concentration in the sample, and is meassured photometricaly. Calibration was performed with tert-butyl-peroxide, and results expressed as mmol/l. Meassurement was performed on plasma samples taken by 98 healthy men, aged 25-55. Reproducibility meassured from day to day showed SD 0, 031 mmol/l and CV 8%. Senitivity limit is 30 mmol/l. Method is linear up to 700 mmol/l. Recovery test showed 122% in assesment of sensitivity. Determined prooxidative species concentration in serum was 43 – 474 mmol/l. Astimated method for determination of prooxidative species concentration showed good results and therefore makes posible further investigations of oxidative status in healthy population as well as pathological cases.

DMPH; oxidative status; lipoperoxide; Fenton reaction

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