Related Experiment Videos
A discrepancy between platelet alpha 2-receptor density and functional circulatory changes in hypertensives
N Mores1, M Martire, G Pistritto
1Istituto di Farmacologia, Università Cattolica del Sacro Cuore, Rome, Italy.
Journal of Cardiovascular Pharmacology
|September 1, 1990
Summary
Essential hypertension is linked to higher platelet alpha 2-adrenoceptor density. However, these receptors do not appear to modulate cardiovascular responses to sympathetic stimuli in hypertensive individuals.
Area of Science:
- Cardiovascular Physiology
- Pharmacology
- Hypertension Research
Background:
- Peripheral alpha 2-adrenoceptors play a role in regulating cardiovascular function.
- Understanding adrenoceptor differences in hypertension is crucial for targeted therapies.
Purpose of the Study:
- To compare platelet alpha 2-adrenoceptor density between normotensive and hypertensive subjects.
- To investigate the role of alpha 2-adrenoceptors in cardiovascular reactivity to sympathetic stimulation in hypertension.
Main Methods:
- Platelet alpha 2-adrenoceptor density was measured using [3H]yohimbine binding in untreated essential hypertensives and normotensive controls.
- Cardiovascular responses (mean arterial pressure, heart rate) to mental arithmetic, static handgrip, and bicycle exercise were assessed.
Main Results:
- Platelet alpha 2-adrenoceptor density was significantly higher in hypertensive subjects (314.8 fmol/mg) compared to normotensive controls (213.6 fmol/mg).
- Receptor affinity was similar between groups.
- No correlation was found between receptor density and cardiovascular changes during sympathetic stimulation tests.
Conclusions:
- Essential hypertension is associated with increased peripheral alpha 2-adrenoceptor density.
- These elevated receptors do not seem to mediate cardiovascular adaptation to sympathetic stimuli in hypertensive patients.