Se status in normal and pathological human individuals before and after Se supplementation

The determination of selenium in plasma and in urine samples has been suggested for the assessment of Se status in human individuals. The kidney is of fundamental importance in Se homeostasis: with low Se intake its excretion will be decreased and with high Se intake it will be increased. In 21 patients with kidney disease (8 with normal kidney function and 13 with moderate renal failure) Se was measured in 1 mi of urine by PIXE after preconcentration of the sample. The total urine volume was measured to calculate total daily Se excretion. The same procedure was applied to 14 normal individuals for comparison. All individuals were then supplemented orally with selenite for 8 weeks (Se = 600 mu g/day) and the procedure was repeated. The behaviour of the major selenoproteins was also investigated by measuring glutathione peroxidase activities in plasma, in platelets and in erythrocyte samples. For renal function, serum and urine creatinine concentrations were utilised and creatinine clearances were calculated. Results obtained were compared before and after Se treatment and between groups. Some correlation studies were carried out between Se and kidney functions and/or selenoperoxidase activities.