for example , pretreatment of chinese hamster fibroblasts ( chw cells ) expressing beta 2-adrenergic receptors ( beta 2ar ) with low ( nanomolar ) concentrations of isoproterenol , a beta-adrenergic agonist , causes decreases in the sensitivity of the cellular adenylyl cyclase response to the agonist , without changing the maximal responsiveness .
C0016030
fibroblasts
C0007634
cellular