ATP-sensitive potassium channels and cardiac protection (part 15). SUMMARY
There is strong evidence that activation of Katp channels constitutes an important link in the protection of the cell against ischemia and reperfusion-induced arrhythmias, contractile dysfunction and, eventually, cell death. It is quite reasonable to speculate that the activation of Katp channels might stimulate permissive effects in the phosphorylation cascade. The underlying molecular machinery, however, has not yet been satisfactorily determined.
The problem of ATP-controlled potassium current in the heart muscle has attracted unfading interest. Katp channels have been studied in isolated fragments of membranes, in isolated myocytes and, indirectly due to their role in cardiac protection in perfused hearts, in animal experiments and even in clinical trials. Results have yielded myriad more or less consistent data. The reason for this focused attention is twofold. First is the endeavour to learn about the natural mechanisms of cellular defence in metabolic need. There appear to be three levels of such a protection: the first fast one is based on electromechanical uncoupling and energy saving; second is the short lived ‘memory’ very likely related to complex processes controlling protein phosphorylation; and third are delayed effects that obviously reflect reprogramming of the proteosynthetic processes of the cell. At all three levels of protection, Katp channels probably play a role.
The second reason that these channels are in the mainstream of interest is an expectation that they may serve as gates for pharmacological aid to the endangered heart. The results obtained so far are promising. Nevertheless, in spite of remarkable achievements, to understand fully the intricate mechanism and the biological role of Katp channels, and to make use of its control are the challenges for the near future. Buy your prescription medications with confidence and without any need for a prescription: buy asthma inhalers to see how little you could be paying for the same quality of your treatment.