The natures of human β3-adrenoceptor (β3-AR) were examined by comparing the other two β-AR subtypes expressed in CHO cells by using radioligand binding assay and cAMP accumulation assay. Isoproterenol and three β3-AR agonists, BRL37344, CL-316,243 and a newly synthesized β3-AR agonist N-5984, were compared for the potency and selectivity for the β3-AR. The affinity and selectivity of N-5984 for β3-ARs was the highest among the four agonists. N-5984 showed higher potency and intrinsic activity of cAMP production than BRL37344 in CHO cells expressing the β3-ARs. CL-316,243 had almost no activity of cAMP production. The three β-AR subtypes showed the nature of G protein-coupled receptors with the constitutive activity with different levels. The cells expressing β3-ARs showed the most highly basal and stimulated adenylyl cyclase activities, although the Bmax was lowest. Thus, β3-ARs seems to be highly coupled with the adenylyl cyclase compared with the other two subtypes.
|Journal||Folia Pharmacologica Japonica|
|Issue number||SUPPL. 1|
|Publication status||Published - 2001 Dec 1|
- Cloned human β-adrenergic receptor
- Constitutive activity
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