Selenium level and glutathione peroxidase activity in plasma, erythrocytes and platelets of healthy Japanese volunteers.

The purpose of this study was to determine both the selenium (Se) level and glutathione peroxidase (GSH-Px) activity in plasma, erythrocytes and platelets from 51 healthy Japanese individuals. The Se levels (mean +/- SD) of plasma, erythrocytes and platelets were 117.4 +/- 15.7 micrograms/L, 0.954 +/- 0.159 microgram/g hemoglobin, and 4.93 +/- 1.52 ng/mg protein, respectively, and GSH-Px activity was 318 +/- 50 U/L, 18.0 +/- 5.0 U/g hemoglobin, and 0.142 +/- 0.035 U/mg protein, respectively. There was a negative correlation between age and the platelet Se level in men (r = -0.761, p < 0.001), and a positive correlation between the plasma and platelet GSH-Px activities in women (r = 0.663, p < 0.001).