受体数量对转染人β2 - 肾上腺素能受体的中国仓鼠卵巢细胞中福斯高林诱导的环磷酸腺苷（cAMP）反应的影响

Influence of receptor number on the cAMP response to forskolin in Chinese hamster ovary cells transfected with human beta2-adrenoceptor.

作者信息

Nakahara Tsutomu, Maruko Takeshi, Sakamoto Kenji, Ishii Kunio

机构信息

Department of Molecular Pharmacology, Kitasato University School of Pharmaceutical Sciences, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan

出版信息

Biol Pharm Bull. 2004 Feb;27(2):239-41. doi: 10.1248/bpb.27.239.

DOI:10.1248/bpb.27.239

PMID:14758043

Abstract

We examined the basal adenosine 3',5'-cyclic monophosphate (cAMP) levels and forskolin-induced cAMP accumulation in cultured Chinese hamster ovary cells (CHO) expressing different levels of human beta(2)-adrenoceptors. Both the basal and forskolin-induced cAMP accumulation in the cells that express higher density of beta(2)-adrenoceptors (CHO-beta(2)/H; 560 fmol/mg protein) were larger than those in the cells that express lower density of beta(2)-adrenoceptors (CHO-beta(2)/L; 270 fmol/mg protein). In addition, isoproterenol-induced cAMP accumulation was also augmented as the number of beta(2)-adrenoceptors was increased. ICI 118,551, a selective beta(2)-adrenoceptor antagonist with inverse agonist properties, decreased all the levels of cAMP observed in both cell lines. These results suggest that the agonist-independent (constitutive) activity of beta(2)-adrenoceptors plays a key role in the control of forskolin-induced cAMP accumulation.

摘要

我们检测了表达不同水平人β₂ - 肾上腺素能受体的培养中国仓鼠卵巢细胞（CHO）中的基础3',5'-环磷酸腺苷（cAMP）水平以及福斯可林诱导的cAMP积累。表达较高密度β₂ - 肾上腺素能受体的细胞（CHO-β₂/H；560 fmol/mg蛋白质）中的基础cAMP水平和福斯可林诱导的cAMP积累均高于表达较低密度β₂ - 肾上腺素能受体的细胞（CHO-β₂/L；270 fmol/mg蛋白质）。此外，随着β₂ - 肾上腺素能受体数量的增加，异丙肾上腺素诱导的cAMP积累也增强。ICI 118,551是一种具有反向激动剂特性的选择性β₂ - 肾上腺素能受体拮抗剂，它降低了两种细胞系中观察到的所有cAMP水平。这些结果表明，β₂ - 肾上腺素能受体的非激动剂依赖性（组成性）活性在福斯可林诱导的cAMP积累控制中起关键作用。