The effect of adenosine (10(-6) M) on the cyclic AMP production in lymphocytes of peripheral blood of patients with bronchial asthma and healthy donors was studied. Cells response to adenosine-induced stimulation was significantly decreased for asthmatic patients as compared to normal subjects. Cortisol (3 x 10(-6) M) was shown to be able to normalize suppressed function of cells of the patients. Adenosine (10(-6) M) changed the distribution of hormone-receptor complexes in lymphocytes of the healthy donors to cause increment of the number of 3H cortisol-receptor complexes bound by nucleus. The treatment of lymphocytes of patients with adenosine didn't give any change in specific nuclear 3H cortisol binding. The obtained results may be used for a rational choice of hormonal therapy.