The influence of sex, age, blood pressure and physical stress on beta 2-adrenoceptor density of mononuclear cells.

The influence of sex, age, blood pressure and physical stress on beta 2-adrenoceptor density on intact mononuclear cells was investigated in normotensives and in patients with essential hypertension using (+/-) 125-iodocyanopindolol as radio-ligand. The intra-individual receptor status under basal conditions at rest was fairly constant. The mean individual deviation of beta 2-adrenoceptor density was 11% after a time period of 3 +/- 1.9 months. The receptor number increased with age: there was a positive correlation (r = 0.59) between age and beta 2-adrenoceptor density. No significant difference existed between men and women matched for age and mean arterial blood pressure (548 +/- 179 versus 481 +/- 246 maximal binding sites per cell). A highly significant positive correlation (r = 0.73) existed between the mean arterial blood pressure and the beta 2-adrenoceptor density over a wide range of normal and increased blood pressure. A factorial analysis revealed a significant correlation between mean arterial pressure and beta 2-adrenoceptor density, but not between age or sex and beta 2-adrenoceptor density. Physical stress led within 15 min to a significant increase in beta 2-adrenoceptors followed by a fall to or even below the starting values after 15 to 30 min rest. It is concluded that beta 2-adrenoceptor density on intact mononuclear cells correlates significantly with mean arterial blood pressure and with age. However, factorial analysis revealed a significant positive correlation only between mean arterial blood pressure and the receptor number but not between age and the receptor number. Sex has no significant influence on the receptor density.(ABSTRACT TRUNCATED AT 250 WORDS)