The ?-adrenoceptor densities and cAMP contents of the lung tissues ofthe experimental allergic asthmatic guinea pigs with and without treatment of galvano-acupuncture were measured by radioligand binding and protein binding assays. The relaxreaction of lung and tracheal strips toward isoproterenal were measused by pharmacological assay. The results were as follows: (1) The ?-receptors densities and cAMP contentsin lung tissues of asthmatic guinea pigs were both lower than those of the normal controls(P