[Mechanisms of asthma of effort]

Forty-six patients with bronchial asthma and preasthma and 6 normal persons were examined before and after graded exercise. Measurements were made of changes in glycogenolysis in peripheral lymphocytes, in blood plasma osmolarity, external respiration function ad diffusion capacity of the lungs, and of blood and sputum eosinophilia. Some of the patients were also examined for blood content of catecholamines. The group of patients with asthma of effort showed, in contrast to those without that illness, the signs of allergic inflammation of the distal parts of the bronchi and a direct correlation between changes in plasma osmolarity and glycogen content in lymphocytes, a decrease in the grade of the glycogenolytic response to adrenaline after exercise. It seems likely that in the pathogenesis of asthma of effort, of certain importance is inadequate reaction of the adrenoreceptor apparatus of the cells to the changes in the microenvironment provoked by exercise, which is manifested by the lack of the rise of beta-adrenoreactivity.