AND ISCHEMIC PRECONDITIONING

Although it is generally assumed that Cx43 is exclusively localized at the sarco-lemma, there is some evidence that this may not be the case. It has been recently shown that the carboxy-terminus of the protein can also be localized at cardiomyocyte nuclei.102 In cultured human endothelial cells, Cx43 was also detected in mitochondria, where its level increased in response to cellular stress.103 Cardiomyocyte mitochondria play an important role in triggering cardioprotection and have been suggested to act as an end-effector of ischemic preconditioning s protection.104110 Most recently, western blot anal- 

Cx43 is involved in ischemia/reperfusion injury and ischemic preconditioning s protection. The exact underlying mechanism(s), how in fact Cx43 mediates protection, remain to be established. 

While IP is effective in healthy hearts of almost all animal species tested so far,112 there is evidence that it might be no longer operative in hearts post myocardial infarction or in failing hearts,113,114 both entities associated with a reduction in myocardial Cx43 expression.115118 

van Veen, H.V.M. van Rijen, T. Opthof, Cardiac gap junction channels modulation of expression and channel properties, Cardiovasc Res 51,217-229 (2001). 

van Rijen, D. Eckardt, J. Degen, M. Theis, T. Ott, K. Willecke, HJ. Jongsma, T. Opthof, J.M. de Bakker, Slow conduction and enhanced anisotropy increase the propensity for ventricular tachyarrhythmias in adult mice with induced deletion of connexin43, Circulation 109, 1048-1055 (2004). 

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Stunning, hibernation and ischemic preconditioning are all elements of acute or chronic heart... 

Lange, M., Smul, T.M., Blomeyer, C.A., Redel, A., Klotz, K.N., Roewer, N., and Kehl, F. 2006. Role of the betal-adrenergic pathway in anesthetic and ischemic preconditioning against myocardial infarction in the rabbit heart in vivo. Anesthesiology 105 503-510. 

Zhao, Z.Q., and Vinten-Johansen, J. 2002. Myocardial apoptosis and ischemic preconditioning. Cardiovasc. Res. 55 438-455. 

L.H. Opie and M.N. Sack, Metabolic plasticity and the promotion of cardiac protection in ischemia and ischemic preconditioning, J. Mol. Cell. Cardiol. 34, 1077-1089(2002). 

E. Novalija, S. Fujita, J.R Kampine and D.F. Stowe, Sevoflurane mimics ischemic preconditioning effects on coronary flow and nitric oxide release in isolated hearts. Anesthesiology 91, 701-712 (1999). 

A2B receptors are found on endothelial cells, where they regulate vascular permeability, and on epithelial cells, where they regulate water secretion. These receptors are upregulated in the hippocampus following cerebral ischemic preconditioning and are thought to play a protective role. Both A2A and A2B receptors contribute to dilation of cerebral microvessels in response to adenosine. 

Endogenous protective programs may include ischemic preconditioning and the heat shock response 571... 

Peart JN, Gross GJ. (2002) Sarcolemmal and mitochondrial K(ATP) charmels and myocardial ischemic preconditioning. J Cell Mol Med 6, 453-64. 

The term, arrhythmogenic substrate, became a matter of interest to many researchers. The arrhythmogenic substrate means the pathologic and anatomic preconditions for the initiation of tachyarrhythmias such as myocardial fibrosis, aneurysm, the border zone between normal and ischemic or infarcted tissue, scars, diffuse myocardial injury in cardiomyopathy or the chronic alterations induced by myocarditis, and furthermore, accessory pathways or variations in the specific cardiac conduction system. These anatomic or pathologic altera-... 

Kemp BK, Cocks TM (1999) Adenosine mediates relaxation of human small resistance-like coronary arteries via A2B receptors. Br J Pharmacol 126(8) 1796-1800 Kersten JR, Toller WG, Gross ER, Pagel PS, Warltier DC (2000) Diabetes abolishes ischemic preconditioning role of glucose, insulin, and osmolality. Am J Physiol Heart Circ Physiol 278(4) H1218-H1224... 

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