23 Reduction of Elevated Intracellular Free Calcium Concentration in Platelets and Blood Pressure in Essential Hypertension by Chronic Treatment with Calcium Antagonists

1984 ◽  
Vol 2 (1) ◽  
pp. 102-103 ◽  
Author(s):  
P Erne ◽  
W Kiowski ◽  
P Bolli ◽  
E B??rgisser ◽  
F R B??hler
Keyword(s):  
Blood Pressure ◽  
Essential Hypertension ◽  
Calcium Antagonists ◽  
Calcium Concentration ◽  
Chronic Treatment ◽  
Intracellular Free Calcium ◽  
Free Calcium ◽  
Intracellular Free Calcium Concentration ◽  
Free Calcium Concentration

Correlation of blood pressure in normotensive and hypertensive individuals with platelet but not lymphocyte intracellular free calcium concentrations

1989 ◽  
Vol 76 (6) ◽  
pp. 631-635 ◽  
Author(s):  
K. Pritchard ◽  
A. E. G. Raine ◽  
C. C. Ashley ◽  
L. M. Castell ◽  
V. Somers ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Systolic Blood Pressure ◽  
Significant Relationship ◽  
Calcium Concentration ◽  
Intracellular Free Calcium ◽  
Ionized Calcium ◽  
Free Calcium ◽  
Fluorescent Indicators ◽  
Intracellular Free Calcium Concentration ◽  
Free Calcium Concentration

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 < 0.05), diastolic blood pressure (r = 0.542, P < 0.02) and mean blood pressure (r = 0.534, P < 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.

The adrenaline -α2-adrenoceptor-mediated vasoconstrictor axis

1985 ◽  
Vol 68 (s10) ◽  
pp. 141s-146s ◽  
Author(s):  
Peter Bolli ◽  
Paul Erne ◽  
Wolfgang Kiowski ◽  
Franz W. Amman ◽  
Fritz R. Bühler
Keyword(s):  
Essential Hypertension ◽  
Calcium Concentration ◽  
Smooth Muscle Contraction ◽  
Intracellular Free Calcium ◽  
Free Calcium ◽  
Plasma Adrenaline ◽  
Α2 Adrenoceptor ◽  
Intracellular Free Calcium Concentration ◽  
Free Calcium Concentration ◽  
Normotensive Subjects

1. In patients with essential hypertension plasma adrenaline concentrations have been found to be higher than in normotensive subjects and this may represent increased adrenergic activity. Adrenaline released into the circulation can be taken up by the sympathetic nerve ending and as it is re-released as a co-transmitter it enhances exocytotic noradrenaline release by stimulating prejunctional β-adrenoceptors and as a consequence it contributes to postjunctional α1-adrenoceptor-induced vasoconstriction. Adrenaline may also induce vasoconstriction via post- and extra-junctional (α2-adrenoceptors, as shown by a decrease in the forearm blood flow during adrenaline infusions in the postjunctional α1- and β-blocked forearm vasculature, an effect that could be antagonized by α2-adrenoceptor blockade with yohimbine. 2. α2-Adrenoceptor stimulation in platelets showed an increased sensitivity to adrenaline, as determined by sensitivity in counteracting the inhibitor effect of PGI2 on intracellular free calcium concentration in untreated patients with essential hypertension, when compared with treated patients or normotensive subjects. As these effects can be normalized by antihypertensive treatment this suggests that the increased hormone sensitivity may be related to the elevated intracellular free calcium concentration. 3. Thus adrenaline, via pre- and post-junctional adrenoceptors, may contribute to enhanced vascular smooth muscle contraction, which most likely is sensitized by the elevated intracellular calcium concentration.

Exercise and platelet intracellular free calcium concentration

1988 ◽  
Vol 75 (2) ◽  
pp. 221-224 ◽  
Author(s):  
Susan M. Barr ◽  
Kennedy R. Lees ◽  
Daniel D. McBryan ◽  
James Reid ◽  
Elizabeth Farish ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Calcium Concentration ◽  
Bicycle Ergometer ◽  
Intracellular Free Calcium ◽  
Free Calcium ◽  
Intracellular Free Calcium Concentration ◽  
Free Calcium Concentration ◽  
Acute Changes ◽  
Pressure Changes

1. A positive correlation between blood pressure and platelet intracellular free calcium concentration ([Ca2+]i) has been reported. We examined the effect of acute changes in blood pressure associated with exercise on platelet [Ca2+]i. 2. Twenty-one subjects had blood pressure and heart rate readings taken after 60 min rest, and subjects were then exercised on a bicycle ergometer at 120 W for 30 min. Blood pressure and heart rate readings were repeated immediately after exercise, 30 min after exercise, and then after a further hour. Blood samples were taken after each set of blood pressure and heart rate readings for catecholamine, lactate and platelet [Ca2+]i estimations. 3. There were significant increases in systolic and diastolic blood pressure, heart rate, and plasma lactate and catecholamine levels during the course of the study. There were no significant changes in platelet [Ca2+]i. 4. These results suggest that the acute blood pressure changes related to exercise are not associated with a change in platelet [Ca2+]i.

Sign in / Sign up

Export Citation Format

Share Document