Volume regulation in mammalian skeletal muscle: the role of sodium–potassium–chloride cotransporters during exposure to hypertonic solutions

Non‐technical summary During moderate to high intensity exercise, there is a net flux of solute‐poor fluid into contracting skeletal muscle. This raises plasma osmolarity, and non‐contracting skeletal muscle and other tissues lose water to the vascular compartment to help maintain blood volume. The loss of water from these non‐contracting tissues causes the cells to shrink. For many tissues the shrinkage of the cells activates the sodium–potassium–chloride cotransporter (NKCC) which is situated in the plasma membrane. Activation of the NKCC reduces the volume loss and functions to restore cell volume in order to prevent cell damage and maintain cellular function. We show that this is also the case for mammalian skeletal myocytes and that the necessary sodium and chloride gradients to maintain NKCC activity depend on the continued activity of the sodium pump (Na+,K+‐ATPase).

Volume regulation in mammalian skeletal muscle: the role of sodium–potassium–chloride cotransporters during exposure to hypertonic solutions Journal Articles