The Rho kinase inhibitor Y-27632 increases erythrocyte deformability and low oxygen tension-induced ATP release

Thuet KM, Bowles EA, Ellsworth ML, Sprague RS, Stephenson AH. The Rho kinase inhibitor Y-27632 increases erythrocyte deformability and low oxygen tension-induced ATP release. Am J Physiol Heart Circ Physiol 301: H1891-H1896, 2011. First published September 2, 2011; doi:10.1152/ajpheart.00603.2011.-Low oxygen (O-2) tension and mechanical deformation are stimuli for ATP release from erythrocytes. It has been shown previously that rabbit erythrocytes made less deformable with diamide, a thiol cross-linking agent, release less ATP in response to low O-2 tension, suggesting a link between these two stimuli. In nonerythroid cells, activation of the Rho/Rho kinase signaling pathway has been reported to decrease cell deformability by altering Rho kinase-dependent cytoskeleton-protein interactions. We investigated the hypothesis that the Rho kinase inhibitor Y-27632 would increase erythrocyte deformability and thereby increase low O-2 tension-induced ATP release from erythrocytes. Here we show that Y-27632 (1 mu M) increases erythrocyte deformability (5%) and increases low O-2 tension-induced ATP release (203%) from healthy human erythrocytes. In addition, we found that, when erythrocytes were made less deformable by incubation with diamide (100 mu M), Y-27632 restored both deformability and low O-2 tension-induced ATP release to levels similar to those measured in the absence of diamide. These findings suggest that the Rho kinase inhibitor Y-27632 is able to reverse the diamide-induced decrease in erythrocyte deformability and rescue low O-2 tension-induced ATP release. These results further support a link between erythrocyte deformability and ATP release in response to low O-2 tension.