ISSN: 1300-0292
İndekslendiği Dizinler: SCIENCE CITATION INDEX EXPANDED
CINAHL, Index Copernicus,
Chemical Abstracts (CA),
Excerpta Medica / EMBASE
Dil: Türkçe, İngilizce
İçerik: Orijinal Araştırma, Derleme, Editöre Mektup, Olgu Sunumu, Tıp Eğitimi, Tıbbi Kitap İncelemeleri
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Adenosine And Cardioprotection
Dr.Nuran EKERBİÇER,a Dr.Necip KUTLUa
aFizyoloji AD, Celal Bayar Üniversitesi Tıp Fakültesi, MANİSA
Brief sublethal periods of myocardial ischemia enhance the myocardium’s tolerance to a period of sustained ischemia and reperfusion. This phenomen was first described by Murry et al and is known as ischemic preconditioning. This cardioprotective phenomenon has been classified into two temporally distinct phases: an early phase, which wanes within 2-4 h, and a late phase, which manifests 24-72 h later. Intense efforts are being made to discover the novel triggers and effectors of preconditioning that could potentially be developed to mimic the effect of ischemic preconditioning. Adenosine is one such agent that has been proposed as an important inducer of both early and delayed pre-conditioning. On myocardial cells, adenosine interacts with various receptor subtypes (A1, A3, and probably A2A ve A2B) that are coupled, via G proteins, to multiple effectors, including enzymes, channels, transporters and cytoskeletal components. The protective action is mediated by A1and A3 receptor subtypes and involves the activation and translocation of PKC to mitochondrial membranes. PKC activation leads to an increased opening of ATP-sensitive K+ channels. Other effectors possibly contributing to cardioprotection by adenosine or preconditioning, and which seem particularly involved in the delayed, second window of protection, include MAP kinases, heat shock proteins, 5’-nucleotidase and iNOS. However, the underlying intracellular signaling mechanisms of protection induced by this agent are not completely understood. More studies are needed to clarify the signalling mechanisms that may promote apoptosis and cellular injury. It is expected that as the mechanism of preconditioning is more thoroughly understood, pharmalogical preconditioning will become practical for clinical use.Keywords: Adenosine, cardioprotection, preconditioning, ischemiaTurkiye Klinikleri J Med Sci 2004, 24:357-371
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