Effects of beta-adrenoceptor blockade on the phenotypic characteristics of thymocytes and peripheral blood lymphocytes

The study revealed that beta-adrenoceptor blockade with propranolol (0.40 mg/100 g/day, s.c.) in adult male DA rats: (i) increased the thymocyte proliferation and apoptosis, (ii) caused disturbances in kinetics of T cell differentiation leading to distinguishable changes in relative proportion of thymocytes at distinct maturational steps and to an expansion of the most mature single positive (CD4+, CD8+) thymocyte pool, (iii) affected the relative proportion of neither CD4+ nor CD8+ peripheral blood lymphocytes (PBL), and (iv) augmented the relative number of CD8+CD25+ cells. Thus, the results suggest the role of beta-adrenoceptors in fine-tuning of T cell maturation, and, possibly, distribution and activation of distinct PBL subsets.