• 22
    Aug
  • ATP-sensitive potassium channels and cardiac protection (part 13)

ATP-sensitive potassium channels and cardiac protection (part 13)

One of the possible candidates for mediating the preconditioning appears to be adenosine-A1 receptor binding because extracellularly applied adenosine exerts similar protection. This idea was partly challenged by the fact that adenosine administration is not always efficient. Later, it was shown that, similarly to adenosine, a number of other endogenous ligands, such as noradrenaline, acetylcholine, endothelin and angiotensin, can simulate the protective effect of short exposure to ischemia.All these ligands activate protein kinase C (PKC) and, in some instances, translocate it . Interestingly, even these alternative pathways of protection may be antagonized by adenosine receptor blocking. In addition, other potentially protective mediators that might be released under conditions of myocardial ischemia (prostacyclin, bradykinin, nitric oxide) may be considered as endogenous cardioprotective substances .

Activation of PKC results in phosphorylation of a variety of proteins, including complex cellular systems, such as adenylate cyclase, L-type calcium channels and very likely the Katp channels . It has been proposed that preconditioning may involve an additional phosphorylation control pathway that is affected by G protein-coupled receptors and operates in parallel with the phospholipase C and PKC pathways. According to one hypothesis, the short lived memory of preconditioning may reside in complex processes that control protein phosphorylation . It’s time for you to stop spending more than your medications are worth: you have a chance to buy ventolin inhalers on very advantageous terms at the best online pharmacy of your choice, any time there is such a need.

 

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