Propranolol affects stress-induced leukocytosis and cellular adhesion molecule expression

Abstract.

In this study, the impact of the β-adrenergic antagonist propranolol on resting and acute psychological- and physical-stress-induced circulating leukocyte numbers and the density of cellular adhesion molecules was investigated. In a randomized double-blind crossover design, 45 healthy volunteers performed a 15-min public speaking task and 21 subjects performed a 16-min bicycle exercise after 5 days of ingesting a placebo and after 5 days of ingesting 100 mg/day propranolol. One week of ingesting propranolol modestly elevated the numbers of CD62L⁺ (P<0.019) but not CD62L^– T-lymphocytes. Moreover, propranolol preferentially blunted-psychological stress-induced increases in naïve T-helper (CD4⁺CD62L⁺; P<0.049) and naïve T-cytotoxic lymphocytes (CD8⁺CD62L⁺; P<0.003), as well as activated T-cytotoxic lymphocytes (CD8⁺CD29⁺; P<0.005). However, exercise-induced increases in leukocyte numbers were enhanced following propranolol treatment (P<0.04). In contrast to the effect on the numbers of adhesion-molecule-bearing cells, there was only a modest effect of propranolol on stress-induced alterations of the density of CD62L, CD54 and CD11a. In this study, propranolol treatment interfered with the adrenergic regulation of circulating leukocyte numbers by blunting psychological stress effects but enhancing exercise effects. Propranolol affected the cell activation status to a lesser extent, as reflected by the density of adhesion molecules.