These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.
Pubmed for Handhelds
PUBMED FOR HANDHELDS
Search MEDLINE/PubMed
Title: Regulation of gap-junction protein connexin 43 by beta-adrenergic receptor stimulation in rat cardiomyocytes. Author: Xia Y, Gong KZ, Xu M, Zhang YY, Guo JH, Song Y, Zhang P. Journal: Acta Pharmacol Sin; 2009 Jul; 30(7):928-34. PubMed ID: 19574999. Abstract: AIM: beta-adrenergic receptor (beta-AR) agonists are among the most potent factors regulating cardiac electrophysiological properties. Connexin 43 (Cx43), the predominant gap-junction protein in the heart, has an indispensable role in modulating cardiac electric activities by affecting gap-junction function. The present study investigates the effects of short-term stimulation of beta-AR subtypes on Cx43 expression and gap junction intercellular communication (GJIC) function. METHODS: The level of Cx43 expression in neonatal rat cardiomyocytes (NRCM) was detected by a Western blotting assay. The GJIC function was evaluated by scrape loading/dye transfer assay. RESULTS: Stimulation of beta-AR by the agonist isoproterenol for 5 min induces the up-regulation of nonphosphorylated Cx43 protein level, but not total Cx43. Selective beta(2)-AR inhibitor ICI 118551, but not beta(1)-AR inhibitor CGP20712, could fully abolish the effect. Moreover, pretreatment with both protein kinase A inhibitor H89 and G(i) protein inhibitor pertussis toxin also inhibited the isoproterenol-induced increase of nonphosphorylated Cx43 expression. Isoproterenol-induced up-regulation of nonphosphorylated Cx43 is accompanied with enhanced GJIC function. CONCLUSION: Taken together, beta(2)-AR stimulation increases the expression of nonphosphorylated Cx43, thereby enhancing the gating function of gap junctions in cardiac myocytes in both a protein kinase A- and G(i)-dependent manner.Acta Pharmacologica Sinica (2009) 30: 928-934; doi: 10.1038/aps.2009.92.[Abstract] [Full Text] [Related] [New Search]