Determination and distribution of human plasma selenoproteins

Major portions of plasma-selenium are incorporated in the proteins glutathi one peroxidase (GSH-Px), selenoprotein P (Sel P) and albumin. A chromatogra phic method, adapted from a procedure by Harrison ct al. [6], uses heparin- and blue-sepharose to separate the three protein fr actions. The determina tion of selenium was carried out by electrothermal atomic absorption spectr oscopy (ETAAS) using the Zeeman effect, The selenium distribution of 17 hea lthy subjects was 68 +/- 7% of the total plasma selenium associated to Sel P, 25 +/- 4% associated to p-GSH-Px and 7+/-4% associated to albumin. The r ecovery of selenium was 99 +/- 4%. For precision measurements a plasma pool has been separated seven times. The selectivity of this method was monitor ed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and GSH-Px activity measurements. A fast method, adapted for clinical appli cations, is described which allows to determine the human plasma selenium d istribution in about an hour.