Studies on the intrinsic activity (efficacy) of human adrenergic receptors. Co-expression of beta 1 and beta 2 reveals a lower efficacy for the beta 1 receptor.
Through co-expression of the human beta 1 and beta 2 adrenergic receptors in a single tester cell (the murine L fibroblast) and through assaying the effect of the beta 1 and beta 2 selective blockers CGP 20712A and ICI 118551 on isoproterenol-stimulated adenylyl cyclase, it is shown that the maximal stimulation achievable with a given cell density of beta 1 adrenergic receptor is less than that obtained with the same density of the beta 2 adrenergic receptor. It is concluded that the efficacy of the 2 receptors differs in that the beta 1 adrenergic receptor has a lower efficacy (or intrinsic activity) than does the beta 2 adrenergic receptor.
Birnbaumer
L
L
Department of Cell Biology, Baylor College of Medicine, Houston, Texas 77030.
Levy
F O
FO
Zhu
X
X
Kaumann
A J
AJ
D000262:Adenylyl Cyclases / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D006801:Humans; D007739:L Cells; D051379:Mice; D008969:Molecular Sequence Data; D009206:Myocardium / Q000378:metabolism; D010869:Pindolol / Q000031:analogs & derivatives / Q000378:metabolism; D011943:Receptors, Adrenergic, beta / Q000032:analysis* / Q000502:physiology*
D011943:Receptors, Adrenergic, beta; C047975:cyanopindolol; D010869:Pindolol; D000262:Adenylyl Cyclases