ATP-sensitive potassium channels and cardiac protection (part 12). THE ROLE OF Katp CHANNELS IN PRECONDITIONING
THE ROLE OF Katp CHANNELS IN PRECONDITIONING
Murry et al first reported that preconditioning by four cycles of 5 mins of ischemia and reperfusion significantly reduced the infarct size in dogs. The protective effect of such preconditioning associated with an inhibition of energy metabolism has been confirmed in various experimental models including isolated myocytes and even in clinical trials . The beneficial effects of ischemic preconditioning are short-lived, lasting some 90 to 120 mins (‘acute memory’). However, still another response to preconditioning is detectable after several hours . This ‘second window of protection’ may last up to several days.
The precise mechanisms of ischemic preconditioning are obviously quite complex. Current research tries not only to list the cellular responses and factors involved but also to unravel the possible signalling pathways. A putative outline of these relations including the role of Katp channels is shown in Figure 3. The most reliable pharmacy that you could be shopping with any moment: it’s available right here and right now You could be getting your proventil inhaler dosage any time of the day or night being sure it will always cost you very little money.
Figure 3 Tentative scheme of cellular mechanisms of cardioprotection due to ischemic preconditioning comprising the possible role of ATP-sensitive potassium channels (Katp). Three modes of protection (immediate, short term, delayed) are indicated by the wide arrows at the bottom. A1, a.1, M2, AT, ET Purinergic, cholinergic, angiotensin, and endothelin receptors; AD Adenosine; G G protein; PKC Protein kinase C. Open arrowheads indicate activation; filled arrowheads indicate inhibition; small arrow indicates transport