Leukocyte adenyl cyclase activity in human bronchial asthma

Changes in adenyl cyclase activity of the peripheral blood leukocytes were investigated in patients with bronchial asthma. Estimation of the leukocyte adenyl cyclase activity was carried out following in vitro stimulation by sodium fluoride (NaF) or metaproternol. The NaF-stimulated adenyl cyclase activity was significantly lower during asthmatic attacks. An oral administration of metaproterenol to patients during an attack was found to enhance the activity back to the control levels. Off-attack asthmatic patients showed a normal value which was again elevated considerably when they were administered metaproterenol. In contrast, measurements of adenyl cyclase activity using metaproterenol stimulation showed little change in patients in spite of asthmatic attacks or metaproterenol regimen. The lowering of the NaF-stimulated leukocyte adenyl cyclase activity was inversely proportional to the degree of lymphopenia during attacks and positively correlated with an increasing percentage of neutrophils.