DECREASE IN BETA-ADRENERGIC RECEPTORS OF LYMPHOCYTES IN SPONTANEOUSLY OCCURRING ACUTE ASTHMA

To clarify changes in beta-adrenergic receptor (BAR) density in spontaneously occurring acute asthma, BAR binding studies were performed on peripheral blood lymphocytes in eight asthmatic and ten normal subjects. Spirometry also was performed. Maximum binding capacity (Bmax) of BAR in acute asthma was significantly lower by 44.2 percent compared with that in stable asthma; FEV1/FVC ratio decreased by 23.9 percent. The Bmax for acute asthma also was significantly lower than that in normal subjects. The Bmax of BAR in all subjects was significantly correlated with FEV1/FVC ratio and percent FEV1. The percentage decrease in the FEV1/FVC ratio and FEV1 from the stable to acute state for each asthmatic subject did not correlate with corresponding percentage decrease in Bmax. These data demonstrate that BAR density of lymphocytes decreases substantially in acute asthma and, simultaneously, suggest that some factors other than the BAR mechanism contribute to the airway obstruction during acute asthma.