The beta-adrenoceptor of the human lymphocyte and human lung parenchyma

1 The response of the beta-adrenoceptors of human lymphocytes to selective agonists and antagonists has been studied quantitatively by measuring changes in cyclic adenosine-3',5'-monophosphate (cyclic AMP) levels. 2 The receptor was activated by isoprenaline and by salbutamol, and blocked by propranolol but not by practolol. A similar pattern of response was obtained with fragments of human lung tissue. 3 The mean value for pA2 for propranolol was 8.34 and for practolol was 3.95. 4 These findings indicate that the lymphocyte beta-adrenoceptor is a beta2-receptor and support the solidity of using lymphocytes to study beta-adrenoceptor function in bronchial asthma. It may also be of use in the evaluation of selective beta2-blocking drugs in man.