Lymphocyte β2-Adrenergic Receptors in Essential Hypertension: Studies in Basal Conditions and After Dynamic Exercise

Abstract

In order to study the density and response to dynamic exercise of lymphocyte β₂-adrenoceptors in essential hypertension, 30 moderate essential hypertensives (12 men: 18 women, mean age 50.3±9.2 years) and 14 normotensive controls (8 men: 7 women, mean age 47±15 years) were studied.

β₂-adrenoceptors density in basal conditions was higher in essential hypertensives than in controls (1950±625 vs 1278±356 binding sites per cell [bs/c], respectively, p < 0.01) (mean ± SD). After dynamic exercise β₂-adrenoceptors density increased both in controls (to 1491±342 bs/c, p < 0.01) and in hypertensives (to 2632±715 bs/c, p < 0.001). However, the percentage of increase after the exercise was significantly higher in hypertensives than in controls (40.5±6.1 vs 20.2±6.5%, p < 0.05). In summary, the higher density in basal conditions, as well as the exaggerated increase in the number of β₂-adrenoceptors after dynamic exercise observed in essential hypertension, suggest an impaired regulation of these receptors in essential hypertension.

Key Words:

• Essential Hypertension
• β-Adrenoceptors
• Lymphocyte Sympathetic Nervous System