Cells containing hemoglobin S have a decreased capacity to maintain normal levels of potassium (K+). As K+ leaves the cell, water follows.
Two mechanisms are responsible for maintaining intracellular ion levels, the Gardos channel and the K+-Cl- cotransporter channel (KCC). Both channels are abnormally activated in patients with sickle cell disease. The resulting loss of water from the cell increases the hemoglobin concentration and the chances for sickling.
