The role of ATP sensitive potassium channels in myocardial protection.

Several factors have pointed to a potential link between ATP sensitive potassium channel activation in ventricular myocytes and the phenomenon of myocardial preconditioning. Preconditioning can be blocked by adenosine antagonists, and is mimicked by adenosine A1-receptor agonists. A portion of the physiological action of adenosine is, however attributable to adenosine actions on KATP channels. The adenosine A1 receptor is reported to be linked to the KATP channel in rat ventricular myocytes by a G-protein mechanism. This article will review the current status of work regarding the role of KATP channels in myocardial preconditioning and will highlight recent work addressing the role of anesthetic effects in these studies. Recent reports and work from our laboratory reveal that several commonly used anesthetic drugs either have direct effects on KATP channels (barbiturates) or have prominent physiological effects that are modulated in large part by KATP channels (volatile anesthetics halothane and isoflurane).