Infrared light stimulates the mitochondrial large-conductance calcium-activated potassium channel in guinea pig cardiomyocytes

Mitochondrial potassium channels play an important role in regulating cellular metabolism, redox balance, and survival, particularly in excitable tissues such as the heart. Among them, the mitochondrial large-conductance calcium-activated potassium (mitoBK _Ca ) channel has been implicated in cardioprotection during ischemia–reperfusion injury. At the same time, growing evidence indicates that mitochondria act as light responsive organelles, with cytochrome c oxidase (COX) serving as a primary chromophore for red and near-infrared (NIR) light. In this study, we investigated whether 820 nm infrared light modulates mitoBK _Ca channel activity in mitochondria isolated from guinea pig cardiomyocytes. Using patch-clamp recordings of mitoplasts, we demonstrated that illumination at 820 nm NIR wavelength enhanced mitoBK _Ca channel activity in a redox-dependent manner. Our findings reveal a previously unrecognized mechanism linking NIR light modulation via COX to the regulation of cardiac mitoBK _Ca channels as a metabolic sensor. This study identifies the mitoBK _Ca channel as a novel effector of light-induced mitochondrial signaling and suggests that modulation of cardiac mitochondrial potassium transport by NIR light may contribute to cardioprotective effects. These results provide new insight into the integration of bioenergetic and photoregulatory processes in mitochondria and support the development of non-pharmacological strategies targeting mitochondrial function.