title: Connexin43 and ischemic preconditioning.
abstract: Connexin43 (Cx43) is the essential protein to form hemichannels and gap junctions in the myocardium. The phosphorylation status of Cx43 which is regulated by a variety of protein kinases and phosphatases determines hemichannel and/or gap junction conductance and permeability. Gap junctions are involved in cell-cell coupling while hemichannels contribute to cardiomyocyte volume regulation. Cx43-formed channels are involved in ischemia/reperfusion injury, since blockade of a large portion of Cx43-formed channels attenuates ischemic hypercontracture, infarct development and post myocardial infarction remodeling. Ischemic preconditioning's protection also depends on functional Cx43-formed channels, since uncoupling of channels or genetic Cx43 deficiency abolishes infarct size reduction by ischemic preconditioning. The exact underlying mechanism(s) how Cx43 mediates protection remain to be established.
authors.affiliation: Institut für Pathophysiologie, Zentrum für Innere Medizin, Universitätsklinikum Essen, Essen, Germany.
authors.forename: Rainer
authors.initials: R
authors.lastname: Schulz
authors.forename: Gerd
authors.initials: G
authors.lastname: Heusch
mesh_terms: D000818:Animals; D018031:Connexin 43 / Q000502:physiology*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000502:physiology; D017629:Gap Junctions / Q000502:physiology; D006706:Homeostasis; D006801:Humans; D019157:Ischemic Preconditioning, Myocardial; D008929:Mitochondria, Heart / Q000378:metabolism; D010766:Phosphorylation; D012508:Sarcolemma / Q000378:metabolism
chemical_list: D018031:Connexin 43; D017868:Cyclic AMP-Dependent Protein Kinases