Effect of chronic beta-adrenergic blockade on exercise-induced leukocytosis.

Chronic beta-receptor blockade on exercise-induced leukocytosis was studied in 11 hypertensive males. Blood samples for determinating leukocytes were taken before and during the 6th min and the 30th min of submaximal exercise, at maximal exercise, and 5 and 15 min after work. Lymphocytosis and granulocytosis were found to be dependent on the intensity and duration of the exercise. Leukocytosis during short-term and long-term exercise was due to both a lymphocytosis and granulocytosis. Under resting conditions, the chronic beta-receptor blockade caused a significant decrease of neutrophil granulocytes. Both the patients and the controls showed the same percent increase in leukocytes compared with the untreated control study. This suggests that the adrenergic system does not play the primary role in exercise-induced leukocytosis.