Selenium metabolism and platelet glutathione peroxidase activity in healthy Finnish men: effects of selenium yeast, selenite, and selenate.
The mean dietary selenium intake in Finland increased from 40 to 100 micrograms/d in 1987 because of the addition in 1985 of selenium to fertilizers. A selenium-supplementation study was performed in 1987 on the same men as were followed in a 1981 study that had a similar design (200 micrograms Se/d). Selenite and selenate, but not selenium yeast increased platelet glutathione peroxidase (GSHPx) activity by 30% compared with placebo, much less than the 70% found in the previous study. Selenium yeast and selenite increased plasma selenium after 11 wk from 1.39 mumol/L to peak values of 2.15 and 1.58 mumol/L, respectively. Only yeast selenium was incorporated into red cells. From a regression plot based on present and literature data, it was estimated that the plasma selenium concentration needed to achieve maximal platelet GSHPx activity was 1.25-1.45 mumol/L. At the present selenium intake in Finland, 100 micrograms/d, GSHPx activity is saturated in plasma and red cells and almost saturated in platelets.
Alfthan
G
G
Department of Biochemistry, National Public Health Institute, (Kansanterveyslaitos), Helsinki, Finland.
Aro
A
A
Arvilommi
H
H
Huttunen
J K
JK
D000704:Analysis of Variance; D001792:Blood Platelets / Q000201:enzymology*; D004032:Diet; D005979:Glutathione Peroxidase / Q000378:metabolism*; D006801:Humans; D008875:Middle Aged; D064586:Selenic Acid; D020887:Selenious Acid; D012643:Selenium / Q000008:administration & dosage / Q000097:blood* / Q000652:urine; D018036:Selenium Compounds; D015003:Yeasts
D018036:Selenium Compounds; D005979:Glutathione Peroxidase; D020887:Selenious Acid; D012643:Selenium; D064586:Selenic Acid