Erythrocyte and plasma Ca2+, Mg2+ and cell membrane adenosine triphosphatase activity in patients with essential hypertension.
OBJECTIVE
To assess the relationships between plasma and intracellular Ca2+, Mg2+ and blood cell membrane adenosine triphosphatase (ATPase) activity in normotensive and hypertensive subjects.


METHODS
Plasma and intracellular Ca2+, Mg2+ were measured with atomic absorption spectrophotometry, and red blood cell membrane Na(+)-K+ ATPase and Ca(2+)-ATPase activities were determined with colorimetric method in 55 patients with essential hypertension and 32 normotensive controls.


RESULTS
The results showed that the hypertensive group consistently demonstrated a significant decreased activity of ATPase studied, with significantly lower plasma Ca2+ and higher cytosolic Ca2+ levels when compared with those in normotensive group (P < 0.01 or P < 0.05, respectively). No significant differences were found in either plasma Mg2+ or intracellular Mg2+ level between the two groups.


CONCLUSIONS
This study suggests that patients with essential hypertension have widespread depression of cell membrane Na(+)-K(+)-ATPase and Ca(2+)-ATPase activities with plasma Ca2+ depletion and cytosolic Ca2+ overload, which may reflect an underlying membrane abnormality in essential hypertension. The cellular abnormalities may be related to the defective transport mechanisms that in turn may be aggravated by plasma Ca2+ depletion.
Fu
Y
Y
Department of Biochemistry, Institute of Experimental Medicine, Hebei Academy of Medical Sciences, Shijiazhuang, China.
Wang
S
S
Lu
Z
Z
Li
H
H
Li
S
S
D000328:Adult; D000368:Aged; D001693:Biological Transport, Active; D017301:Ca(2+) Mg(2+)-ATPase / Q000378:metabolism*; D002118:Calcium / Q000097:blood*; D004910:Erythrocyte Membrane / Q000201:enzymology; D004912:Erythrocytes / Q000378:metabolism*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood*; D008274:Magnesium / Q000097:blood*; D008297:Male; D008875:Middle Aged; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism
D017301:Ca(2+) Mg(2+)-ATPase; D000254:Sodium-Potassium-Exchanging ATPase; D008274:Magnesium; D002118:Calcium