Cytoprotective Role of Ca 2+ - Activated K + Channels in the Cardiac Inner Mitochondrial Membrane

Abstract

Ion channels on the mitochondrial inner membrane influence cell function in specific ways that can be detrimental or beneficial to cell survival. At least one type of potassium (K + ) channel, the mitochondrial adenosine triphosphate–sensitive K + channel (mitoK ATP ), is an important effector of protection against necrotic and apoptotic cell injury after ischemia. Here another channel with properties similar to the surface membrane calcium-activated K + channel was found on the mitochondrial inner membrane (mitoK Ca ) of guinea pig ventricular cells. MitoK Ca significantly contributed to mitochondrial K + uptake of the myocyte, and an opener of mitoK Ca protected hearts against infarction.