How does the mitochondria regulate cardiac L-type Ca2+ channel function?

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Oxygen is vital to cellular metabolism and function. Oxygen delivery to cells is critical and a lack of oxygen such as occurs during a heart attack can be lethal. The L-type Ca2+ channel is a protein in the membrane of heart muscle cells responsible for regulating the entry of calcium into heart muscle cells. It plays a role in maintaining the heart beat and contraction. We have found that a lack of oxygen (hypoxia) alters the function of the L-type Ca2+ channel and its response to adrenergic stimulation (adrenaline).This may be one of the ways that rhythm disturbances or sudden cardiac death occurs with a heart attack. The activity of the L-type Ca2+ channel is sensitive to changes in reactive oxygen species caused by changes in oxygen concentration. The reactive oxygen species are generated from a part of the cell responsible for maintaining the cell's energy requirements (the mitochondria). Oxidative stress is a feature of various cardiovascular pathologies and we are now interested in determining the effect of oxidative stress on function of the L-type Ca2+ channel and the role of the mitochondria in generating reactive oxygen species. Oxidative stress can damage mitochondria leading to an increase in production of reactive oxygen species. We will determine how oxidative stress damages the mitochondria and how this then alters the channel function, directly or indirectly. The information gained will provide insight into how reactive oxygen species influence L-type Ca2+ channel function and the mechanisms that contribute to pathology involving reactive oxygen species such as heart failure and arrhythmia.