Beta adrenergic blockade in asthmatic children and the effect of bronchodilators

ABSTRACT

The beta adrenergic function was assessed in 30 asthmatic and 15 healthy children by measuring the epinephrine induced rise in urinary cAMP excretion. Asthmatic children excreted less cAMP, especially when suffering from respiratory distress. In addition, they showed subnormal rise in urinary cAMP excretion following s.c. epinephrine injection. Oral aminophylline and prednisone increased both basal and epinephrine-induced response in cAMP excretion by asthmatic children. No such effects were observed after oral ephedrine. Beta adrenergic blockade appears to be a basic abnormality in the pathogenesis of bronchial asthma. Bronchodilator drugs are not responsible for this blockade. On the contrary, aminophylline and prednisone appear to help overcome this blockade