Electrophysiological analysis of cardiac KATP channel
image: Workflow of mouse cardiomyocyte isolation and patch clamp recording. A Langendorff perfusion system. Schematic representation of the Langendorff method for isolating cardiomyocytes. The heart is excised from the mouse, followed by perfusion with an enzyme-containing solution to dissociate cells. B Heart digestion. Image of the mouse heart being digested using the Langendorff perfusion system. The perfusion needle is inserted into the aorta, and the heart is perfused with collagenase solution. C Isolated cardiomyocytes. Light microscopy image showing isolated adult mouse cardiomyocytes. The cells are shown to disperse after enzymatic digestion. Scale bar, 50 μm. D Patch clamp setup. Image of a cardiomyocyte being patched with a glass micropipette. The cell is positioned under an inverted microscope, and the pipette is used to form a high-resistance seal for recording. Scale bar, 50 μm
Credit: HIGHER EDUCATON PRESS
ATP-sensitive potassium (KATP) channels are integral components in excitable cells, particularly in cardiomyocytes, serving as critical regulators of cellular metabolism and electrical excitability. In instances of prolonged oxygen deprivation or heightened metabolic requirements, the opening of KATP channels enables potassium efflux by virtue of a diminished ATP/ADP ratio. This process aids in maintaining membrane potential stability, thereby mitigating excessive excitability and cellular contraction, ultimately contributing significantly to cardiac protection. The accurate isolation of intact single cardiomyocytes and the electrophysiological evaluation of KATP channels are pivotal processes in research on KATP channels in cardiomyocytes in vitro. Here, we present a comprehensive protocol not only for the efficient isolation of viable cardiomyocytes from the adult mouse through the Langendorff perfusion method, but also for the recording of KATP channel currents in single cardiomyocytes employing patch clamp technique.