Burn-induced red blood cell deformability and shape changes are modulated by sex hormones

Background: Burns are known to cause changes in red blood cell (RBC) deformability and resting shape. However, it is unclear whether sex and sex hormones can influence the severity of these alterations. Methods: Red blood cell deformability and shape were examined in proestrus and diestrus female rats, ovariectomized female rats, as well as castrated and noncastrated male rats (6 animals per group) subjected to scald burn. Red blood cell deformability was measured by laser ektacytometry and erythrocyte shape was evaluated by scanning electron microscopy. Results: Burn-induced RBC deformability changes (decrease in elongation index) and shape alterations (increase in the percentage of reversibly and irreversibly changed cells) were less severe in proestrus females than in diestrus females or males. Ovariectomized rats demonstrated more severe RBC changes than nonovariectomized ones. The degree of RBC damage was the same in castrated and noncastrated males. Conclusions: Removal of female sex hormones increases the severity of burn-induced RBC, indicating that female sex hormones protect against burn-induced RBC dysfunction. In contrast, male sex hormones do not appear to modulate burn-induced RBC dysfunction.