%0 Journal Article
%T Different patterns of agonist-induced modulation of ¦Á1B-adrenoceptor density at different initial expression levels
%A Beilei Lei
%A Qide Han
%J Chinese Science Bulletin
%@ 1861-9541
%D 2000
%I 
%R 10.1007/BF02886215
%X We compared the norepinephrine (NE) induced ¦Á1B-adrenoceptor (¦Á1B-AR) expression modulation between two transfected human embryonic kidney (MEK) 293 cell lines in which ¦Á1B-AR densities were (6 336 ¡À 913) and (773 ¡À 164) fmol   mg1, respectively. Treatment of cells with NE (10 ¦Ìmol   L1) for 48 h decreased high-level expressed ¦Á1B-AR density, but increased low-level expressed ¦Á1B-AR density. The protein kinase C inhibitor Calphostin C or Ro-31-8220 reversed, and its activator PMA mimicked the NE-induced down-regulation of high-level expressed ¦Á1B-AR. Moreover, PMA induced a down-regulation of low-level expressed ¦Á1B-AR. The endoplasmic reticulum Ca2+-ATPase inhibitor cyclopiazonic acid (CPA) and the calcium chelator BAPTA/AM did not affect the down-regulation of high-level expressed ¦Á1B-AR, but inhibited the up-regulation of low-level expression ¦Á1B-AR induced by NE. These results suggest that ¦Á1B-adrenoceptor densities at different initial expression levels are differentially regulated by NE and their signal transduction pathways are different.
%K ¦Á1B-adrenoceptor
%K human embryonic kidney cells
%K regulation
%K signal transduction
%U http://link.springer.com/article/10.1007/BF02886215