Race and sex differences in erythrocyte Na+, K+, and Na+-K+-adenosine triphosphatase.
Several reports indicate that erythrocytes (RBCs) from blacks and men have higher sodium concentrations than those from whites and women. One possible mechanism to explain this finding is a difference in the activity of Na+-K+-ATPase. To explore this possibility, we have studied the Na+ and K+ kinetics of RBC Na+-K+-ATPase and RBC Na+ and K+ concentrations in 37 normotensive blacks and whites, both males and females. The maximal initial reaction velocity (Vmax) values for RBC Na+-K+-ATPase were lower in blacks and men as compared with whites and women. Higher RBC Na+ levels were observed in blacks and males vs. whites and females. Significant inverse correlations were noted between the Na+-K+-ATPase activity and RBC Na+ concentrations. These findings indicate that cellular Na+ homeostasis is different in blacks and men as compared with whites and women. Since higher RBC Na+ concentrations have also been observed in patients with essential hypertension as compared with normotensive subjects, the higher intracellular Na+ concentrations in blacks and men may contribute to the greater predisposition of these groups to essential hypertension.
Lasker
N
N
Hopp
L
L
Grossman
S
S
Bamforth
R
R
Aviv
A
A
D000328:Adult; D044383:Black People; D004231:Diuresis; D004789:Enzyme Activation; D004912:Erythrocytes / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D011188:Potassium / Q000097:blood*; D012083:Renin / Q000097:blood; D012737:Sex Factors; D012964:Sodium / Q000097:blood*; D000254:Sodium-Potassium-Exchanging ATPase / Q000097:blood*; D044465:White People
D012964:Sodium; D012083:Renin; D000254:Sodium-Potassium-Exchanging ATPase; D011188:Potassium