Internalization and distribution of three α_1-adrenoceptor subtypes in HEK293A cells before and after agonist stimulation  

作　　者：Shu-yi WANG Yao SONG Ming XU Qi-hua HE Qi-de HAN You-yi ZHANG 

机构地区：[1]Institute of Vascular Medicine, Peking University Third Hospital and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing 100083, China [2]Center of Medical Analysis, Peking University, Health Science Center, Beijing 100083, China

出　　处：《Acta Pharmacologica Sinica》2007年第3期359-366,共8页中国药理学报（英文版）

基　　金：Project supported by the National Key Basic Research Program of the People's Republic of China(No G2000056906);the National Natural Science Foundation of China(No 30490172,30171083).

摘　　要：Aim： To examine the subcellular distribution of the 3 α1-adrenoceptor （α1-AR） subtypes and their internalization and trafficking upon agonist stimulation in human embryonic kidney 293A cells. Methods： Confocal real-time imaging, enzyme linked immunosorbent assay （ELISA） and whole cell [^3H]-prazosin binding assay were applied to detect the distribution and localization of the 3 α1-AR subtypes. Results： （α1A-AR was found both on the cell surface and in the cytoplasm; α1B- AR, however, was predominantly detected on the cell surface, while α1D-AR was detected mainly in the intracellular compartments. After stimulation with phenylephrine, localization changes were detected by confocal microscopy for α1A- and α1B-AR, but the localization of α1D-AR were unaffected. Phenylephrine stimulation promoted a more rapid internalization of α1B-AR than α1A-AR, α1D-AR internalization was detected only by ELISA. Whole cell [^3H]-prazosin binding assay showed that α1A-AR functional receptors were detected both on the cell surface and in the cytoplasm; α1B-AR, however, were detected predominantly on the cell surface, while α1D-AR were detected mainly in intracellular compartments. Phenylephrine stimulation promoted internalization of α1A- and α1B-AR. Conclusion： Phenylephrine stimulation induced changes in the localization of the 3 α1-AR.Aim： To examine the subcellular distribution of the 3 α1-adrenoceptor （α1-AR） subtypes and their internalization and trafficking upon agonist stimulation in human embryonic kidney 293A cells. Methods： Confocal real-time imaging, enzyme linked immunosorbent assay （ELISA） and whole cell [^3H]-prazosin binding assay were applied to detect the distribution and localization of the 3 α1-AR subtypes. Results： （α1A-AR was found both on the cell surface and in the cytoplasm; α1B- AR, however, was predominantly detected on the cell surface, while α1D-AR was detected mainly in the intracellular compartments. After stimulation with phenylephrine, localization changes were detected by confocal microscopy for α1A- and α1B-AR, but the localization of α1D-AR were unaffected. Phenylephrine stimulation promoted a more rapid internalization of α1B-AR than α1A-AR, α1D-AR internalization was detected only by ELISA. Whole cell [^3H]-prazosin binding assay showed that α1A-AR functional receptors were detected both on the cell surface and in the cytoplasm; α1B-AR, however, were detected predominantly on the cell surface, while α1D-AR were detected mainly in intracellular compartments. Phenylephrine stimulation promoted internalization of α1A- and α1B-AR. Conclusion： Phenylephrine stimulation induced changes in the localization of the 3 α1-AR.

关 键 词：ADRENOCEPTOR agonist stimulation confocalimage enzyme-linked immunosorbent assay [3H]-prazosin binding assay INTERNALIZATION subcellular distribution subtype 

分 类 号：R962[医药卫生—药理学]