Adrenergic desensitization in leukocytes of normal and asthmatic subjects

Cyclic AMP was measured in leukocytes of normal and asthmatic subjects before and after one week of treatment with equal amounts of ephedrine. During the control and placebo periods, the measurements of cyclic AMP in leukocytes of asthmatic subjects were similar to those of normal individuals. After one week of treatment with ephedrine, both groups exhibited suppression of the leukocyte cyclic AMP response to adrenergic stimulation in vitro: however, the suppression of response was significantly greater in asthmatic subjects (p less than .u1). Subcutaneous administration of epinephrine was followed by further suppression of the leukocyte cyclic AMP response to in vitro stimulation which was similar in both groups during all treatment periods. The results indicate that in vivo exposure to adrenergic medications is followed by desensitization of the leukocyte responses to subsequent adrenergic stimulation in vitro. After administration of small doses of medication, the severity and/or duration of desensitization is significantly greater in asthmatic leukocytes.