Changes in erythrocyte deformability in NaCl-induced right-sided cardiac failure in broiler chickens

In this study, we tested the hypothesis that erythrocyte deformability is decreased in the development of cardiac failure induced by NaCl toxicosis. Deformability of erythrocytes and routine hematologic and biochemical variables were measured in 6 of 50 chickens that were given 5 g of NaCl/L in their drinking water from day 7 to day 42, and were compared with values in 6 of 50 healthy chickens given free access to tap water. Deformability was assessed by passing a 10% suspension of erythrocytes through a polycarbonate membrane with 5-microns pores. Chickens were euthanatized and heart and body weights were determined. Treatment with NaCl induced right-sided cardiac failure up to day 28. The ratios of heart weight to body weight were greater, for right ventricle by 20 to 64% and for left ventricle by 15 to 27%, attributable to NaCl treatment. Deformability of erythrocytes of NaCl-treated chickens was markedly decreased, in association with increased erythrocyte size and plasma Na+ concentration. However, only part of the decreased deformability could be explained by swelling of erythrocytes. Decreased deformability could not be explained by increased cell viscosity because mean corpuscular hemoglobin concentration, the primary determinant of erythrocyte viscosity, was decreased. Because decreased deformability of erythrocytes has been demonstrated previously to be associated with increased vascular resistance, decreased deformability may have contributed to the development of right-sided cardiac failure in these chickens.