Beta-blocker action on lymphocyte proliferative response in essential hypertension.

The proliferative response of phytohaemagglutinin (PHA) - stimulated lymphocytes of healthy donors and hypertensive subjects was analysed according to 3H-thymidine incorporation and cell cycle phase position on a flow cytofluorimeter. 3H-thymidine uptake and the percentage of cells in (S + G2) phase were significantly lower in hypertensive patients. After short-term propranolol administration the lymphocyte blastogenic response in essential hypertension increased by 30--100%. The data suggest that the change in mitogenic response of lymphocytes in essential hypertension results from changes in the distribution of lymphocyte subclasses. The connection between the sympathoadrenal and immune system is discussed.