Selenium content and selenium-dependent glutahione peroxidase activity in plasma and erythrocytes methods and reference values

Selium is one of the eight oligoelements essential to the human body. It binds to the glutathione peroxidase enzymes and plays a role in the mechanisms that prevent tissue injury by oxigen radicals. Selenium deficiencie have been found in close relationship with several diseases, some of them fatal (e.g. cardiomycopathy, cancer). A method suitable for practical use in hospital laboratories has been developed for detecting and monitoring patients risking selenium deficiency or excess. The method was first applied for the routine determination of selenium content in plasma (P-Se) and erythrocytes (GR-Se), and the selenium-dependent glutathione peroxidase activity (GSHPx-Se) in plasma and erythrocytes. Normal selinium contents were thus established, to be used both as normality indices for the Italian population, and as reference values for the calibration of the method itself. Two different normal population samples were examined: 21 healthy subjects, and 20 patients hospitalized for minor surgery. The results of the statistical analyses, when considered separately for the two samples, the two subsets formed according to sex, and the whole aggregate sample, show a close proximity of mean and median values, thus indicating a clinically homogeneous sampling representative of normal conditions. A listing of literature on such normal parameters is included for reference. Selenium values found in patients showing clinical symptoms indicative of selenium deficiency are also reported: such values are well below normal, most of them below the 2.5 percentile. (RINPE 1989; 7: 145-55)