thus , although measurements of beta-adrenergic receptors on circulating mononuclear leukocytes can be used as indices of extravascular target tissue beta-adrenergic receptor densities ( at least in lung and heart ) , it would appear that extravascular tissues should be used to study adrenergic receptor regulation by endogenous catecholamines in humans .
C0001643
beta-adrenergic receptor
C0034783
adrenergic receptor