To the Editor.—
I read with interest the article by Kok et al.1 The authors state that data on erythrocyte (red blood cell) glutathione peroxidase (GSH-Px) (EC 18.104.22.168) activity in patients who have had a myocardial infarction have not been published.We are working on this problem. It is known that GSH-Px is one of the major enzymes involved in the protection of the cell against antiperoxidation, particularly the cells of heart muscle. Selenium-containing GSH-Px acts on hydrogen peroxide and lipids or other organic hydroperoxides.2 Doroshow et al3 found that in heart tissue catalase was almost absent and superoxide dismutase had only 27% of the activity found in liver. Only GSH-Px activity is high both in liver and in heart tissues. Batist et al4 demonstrated that changes in this enzyme in heart cells and in erythrocytes are well correlated.
We determined red blood cell GSH-Px