[Determination of human erythrocyte membrane Na+/K(+)-ATPase activity in small volume of blood sample].
Na+/K(+)-ATPase of the cell membrane is considered to be closely related to the pathology of various diseases including hypertension and heart failure. The activity of this enzyme in the erythrocyte membrane has been determined in earlier reports by the assay of inorganic phosphate generated from the substrate ATP or radioimmunoassay after binding 3H ouabain to the erythrocyte membrane, using a large volume of blood samples. However, as neither method was appropriate for wide routine use, we developed a method to assay this enzyme in a small volume (10 ml) of fresh human blood samples with re-evaluation of conditions for the inorganic phosphate assay. In this method, the coefficient value (CV) of membrane protein amount and the NA+/K(+)-ATPase activity were 2.2% and 2.5% respectively, indicating sufficient precision of the assay. Moreover, in 97 subjects without abnormalities in blood biochemical tests (77 males and 20 females) aged 35-59 years, the enzyme activity showed no differences according to age or sex, ranging from 0.217 to 0.071 mumols Pi/mg/hr with a mean of 0.130.
Teraoka
K
K
Medical Research Institute Kanazawa Medical University, Ishikawa.
Miyagoshi
M
M
Fujikawa
K
K
Odajima
S
S
Sugita
T
T
Asaji
T
T
Matsui
S
S
Tsuritani
I
I
Honda
R
R
Yamada
Y
Y
D000328:Adult; D001800:Blood Specimen Collection; D004910:Erythrocyte Membrane / Q000201:enzymology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010710:Phosphates / Q000097:blood; D012016:Reference Values; D000254:Sodium-Potassium-Exchanging ATPase / Q000097:blood*
D010710:Phosphates; D000254:Sodium-Potassium-Exchanging ATPase