Correlation of blood pressure in normotensive and hypertensive individuals with platelet but not lymphocyte intracellular free calcium concentrations.
1. Fifty-two normotensive and essential hypertensive subjects were studied. Intracellular free calcium concentration [( Ca2+]i) was measured in lymphocytes (37 subjects) and platelets (18 subjects) by means of the fluorescent indicators, quin 2 and fura-2. In 31 subjects, plasma ionized calcium concentration was also measured. 2. There was a positive correlation between platelet [Ca2+]i and systolic blood pressure (r = 0.485, P less than 0.05), diastolic blood pressure (r = 0.542, P less than 0.02) and mean blood pressure (r = 0.534, P less than 0.02). 3. No statistically significant relationship was observed between plasma ionized calcium and blood pressure. 4. No relationship was found between lymphocyte [Ca2+]i and blood pressure, or between lymphocyte [Ca2+]i and plasma ionized calcium. 5. There was no relationship between [Ca2+]i of lymphocytes and platelets measured simultaneously from the same subject. 6. These findings reconcile previous conflicting reports and show a relationship between platelet but not lymphocyte [Ca2+]i and blood pressure in man.
Pritchard
K
K
University Laboratory of Physiology, Oxford, U.K.
Raine
A E
AE
Ashley
C C
CC
Castell
L M
LM
Somers
V
V
Osborn
C
C
Ledingham
J G
JG
Conway
J
J
D000328:Adult; D000368:Aged; D001792:Blood Platelets / Q000378:metabolism*; D001794:Blood Pressure; D002118:Calcium / Q000097:blood*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000503:physiopathology*; D008214:Lymphocytes / Q000378:metabolism*; D008297:Male; D008875:Middle Aged
D002118:Calcium