Connexins in the sinoatrial and atrioventricular nodes. 2006

M R Boyett, and S Inada, and S Yoo, and J Li, and J Liu, and J Tellez, and I D Greener, and H Honjo, and R Billeter, and M Lei, and H Zhang, and I R Efimov, and H Dobrzynski
Division of Cardiovascular and Endocrine Sciences, University of Manchester, Manchester; UK.

The sinoatrial node (SAN) and the atrioventricular node (AVN) are specialized tissues in the heart: the SAN is specialized for pacemaking (it is the pacemaker of the heart), whereas the AVN is specialized for slow conduction of the action potential (to introduce a delay between atrial and ventricular activation during the cardiac cycle). These functions have special requirements regarding electrical coupling and, therefore, expression of connexin isoforms. Electrical coupling in the center of the SAN should be weak to protect it from the inhibitory electrotonic influence of the more hyperpolarized non-pacemaking atrial muscle surrounding the SAN. However, for the SAN to be able to drive the atrial muscle, electrical coupling should be strong in the periphery of the SAN. Consistent with this, in the center of the SAN there is no expression of Cx43 (the principal connexin of the working myocardium) and little expression of Cx40, but there is expression of Cx45 and Cx30.2, whereas in the periphery of the SAN Cx43 as well Cx45 is expressed. In the AVN, there is a similar pattern of expression of connexins as in the center of the SAN and this is likely to be in large part responsible for the slow conduction of the action potential.

UI MeSH Term Description Entries
D006801 Humans Members of the species Homo sapiens. Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000097003 Gap Junction alpha-5 Protein A GAP JUNCTION alpha subunit containing four transmembrane domains expressed in the atrial myocardium and ventricular HEART CONDUCTION SYSTEM including PURKINJE FIBERS. Mutations in the human gene GJA5 are associated with cardiac conduction abnormalities such as a familial ATRIAL FIBRILLATION. Connexin 40,Connexin 40 Protein,GJA5 Protein,Gap Junction A5,Gap Junction alpha5 Protein,Gap Junction alpha 5 Protein,Protein, Connexin 40,Protein, GJA5
D000200 Action Potentials Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli. Spike Potentials,Nerve Impulses,Action Potential,Impulse, Nerve,Impulses, Nerve,Nerve Impulse,Potential, Action,Potential, Spike,Potentials, Action,Potentials, Spike,Spike Potential
D000818 Animals Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA. Animal,Metazoa,Animalia
D001283 Atrioventricular Node A small nodular mass of specialized muscle fibers located in the interatrial septum near the opening of the coronary sinus. It gives rise to the atrioventricular bundle of the conduction system of the heart. AV Node,A-V Node,Atrio-Ventricular Node,A V Node,A-V Nodes,AV Nodes,Atrio Ventricular Node,Atrio-Ventricular Nodes,Atrioventricular Nodes,Node, A-V,Node, AV,Node, Atrio-Ventricular,Node, Atrioventricular,Nodes, A-V,Nodes, AV,Nodes, Atrio-Ventricular,Nodes, Atrioventricular
D012849 Sinoatrial Node The small mass of modified cardiac muscle fibers located at the junction of the superior vena cava (VENA CAVA, SUPERIOR) and right atrium. Contraction impulses probably start in this node, spread over the atrium (HEART ATRIUM) and are then transmitted by the atrioventricular bundle (BUNDLE OF HIS) to the ventricle (HEART VENTRICLE). Sinuatrial Node,Sinus Node,Sino-Atrial Node,Sinu-Atrial Node,Node, Sino-Atrial,Node, Sinoatrial,Node, Sinu-Atrial,Node, Sinuatrial,Node, Sinus,Nodes, Sino-Atrial,Nodes, Sinoatrial,Nodes, Sinu-Atrial,Nodes, Sinuatrial,Nodes, Sinus,Sino Atrial Node,Sino-Atrial Nodes,Sinoatrial Nodes,Sinu Atrial Node,Sinu-Atrial Nodes,Sinuatrial Nodes,Sinus Nodes
D013617 Tachycardia, Supraventricular A generic expression for any tachycardia that originates above the BUNDLE OF HIS. Supraventricular Tachycardia,Supraventricular Tachycardias,Tachycardias, Supraventricular
D015854 Up-Regulation A positive regulatory effect on physiological processes at the molecular, cellular, or systemic level. At the molecular level, the major regulatory sites include membrane receptors, genes (GENE EXPRESSION REGULATION), mRNAs (RNA, MESSENGER), and proteins. Receptor Up-Regulation,Upregulation,Up-Regulation (Physiology),Up Regulation
D017629 Gap Junctions Connections between cells which allow passage of small molecules and electric current. Gap junctions were first described anatomically as regions of close apposition between cells with a narrow (1-2 nm) gap between cell membranes. The variety in the properties of gap junctions is reflected in the number of CONNEXINS, the family of proteins which form the junctions. Gap Junction,Junction, Gap,Junctions, Gap
D017630 Connexins A group of homologous proteins which form the intermembrane channels of GAP JUNCTIONS. The connexins are the products of an identified gene family which has both highly conserved and highly divergent regions. The variety contributes to the wide range of functional properties of gap junctions. Connexin,Connexin Complex Proteins,Gap Junction Proteins,Gap Junction Channel Proteins,Gap Junction Protein,Junction Protein, Gap,Junction Proteins, Gap

Related Publications

M R Boyett, and S Inada, and S Yoo, and J Li, and J Liu, and J Tellez, and I D Greener, and H Honjo, and R Billeter, and M Lei, and H Zhang, and I R Efimov, and H Dobrzynski
August 1970, Laboratory investigation; a journal of technical methods and pathology,
M R Boyett, and S Inada, and S Yoo, and J Li, and J Liu, and J Tellez, and I D Greener, and H Honjo, and R Billeter, and M Lei, and H Zhang, and I R Efimov, and H Dobrzynski
January 1982, Grudnaia khirurgiia (Moscow, Russia),
M R Boyett, and S Inada, and S Yoo, and J Li, and J Liu, and J Tellez, and I D Greener, and H Honjo, and R Billeter, and M Lei, and H Zhang, and I R Efimov, and H Dobrzynski
March 1973, Circulation research,
M R Boyett, and S Inada, and S Yoo, and J Li, and J Liu, and J Tellez, and I D Greener, and H Honjo, and R Billeter, and M Lei, and H Zhang, and I R Efimov, and H Dobrzynski
November 1988, The American journal of physiology,
M R Boyett, and S Inada, and S Yoo, and J Li, and J Liu, and J Tellez, and I D Greener, and H Honjo, and R Billeter, and M Lei, and H Zhang, and I R Efimov, and H Dobrzynski
October 1986, The American journal of physiology,
M R Boyett, and S Inada, and S Yoo, and J Li, and J Liu, and J Tellez, and I D Greener, and H Honjo, and R Billeter, and M Lei, and H Zhang, and I R Efimov, and H Dobrzynski
March 1989, Kardiologiia,
M R Boyett, and S Inada, and S Yoo, and J Li, and J Liu, and J Tellez, and I D Greener, and H Honjo, and R Billeter, and M Lei, and H Zhang, and I R Efimov, and H Dobrzynski
January 1980, Journal of molecular and cellular cardiology,
M R Boyett, and S Inada, and S Yoo, and J Li, and J Liu, and J Tellez, and I D Greener, and H Honjo, and R Billeter, and M Lei, and H Zhang, and I R Efimov, and H Dobrzynski
September 1990, Zhongguo yao li xue bao = Acta pharmacologica Sinica,
M R Boyett, and S Inada, and S Yoo, and J Li, and J Liu, and J Tellez, and I D Greener, and H Honjo, and R Billeter, and M Lei, and H Zhang, and I R Efimov, and H Dobrzynski
September 1975, The American journal of cardiology,
M R Boyett, and S Inada, and S Yoo, and J Li, and J Liu, and J Tellez, and I D Greener, and H Honjo, and R Billeter, and M Lei, and H Zhang, and I R Efimov, and H Dobrzynski
June 1998, British journal of pharmacology,
Copied contents to your clipboard!