Erythrocyte membrane Na+ and K+ activated adenosine triphosphatase in protein-calorie malnutrition.

Total, ouabain insensitive and ouabain sensitive Na+ and K+ adenosine triphosphatase activity in the erythrocyte membrane of protein-calorie malnourished children with marasmus and kwashiorkor was compared with the enzyme activity in apparently healthy children (normals). Na+ and K+ contents of erythrocyte and plasma were also determined in these patients. Specific activity (units per milligram of membrane protein) of ouabain sensitive Na+ and K+ adenosine triphosphatase was significantly higher in erythrocyte membrane preparations from children with kwashiorkor but not from children with marasmus. After 4 to 5 weeks of treatment with diets sufficient in protein and calories the specific activity of the enzyme was lower as compared to that on admission. Erythrocyte and plasma Na+ content (microgram/10(6) cells and microgram per milliliter of plasma) in children with kwashiorkor were not different from those in normal children, however, there was reduction in K+ content of erythrocytes and plasma of these children. After treatment, erythrocyte Na+ and K+ and plasma K+ in children with kwashiorkor increased significantly. In marasmic children erythrocyte Na+ was higher as compared to normal but there were no differences in K+ content of either eyrthrocytes or plasma in these children.