Age and sex-dependent effects of nitrosative stress on the osmotic fragility of human red blood cells

Abstract Objectives Nitrosative stress is defined as a condition in which oxidative stress accompanies the presence of excess NO and they both may alter the integrity of the red blood cell membrane (RBC). In this study, age- and sex-related effects of nitrosative stress on the membrane osmotic fragility of RBC were investigated using NO and superoxide donors in the RBC isolated from participants. Methods A total of 119 men and women volunteers, both young and old, provided blood samples for the study. The effects of NO precursor L-arginine, Nitric Oxide Synthase (NOS) inhibitor L-NMMA, long-acting NO donor Diethylenetriamine/NO (DETA10 −6 –10 −4 M), short-acting NO donor Diethylamine-NONOate (DEA10 −6 –10 −4 M) and superoxide donor pyrogallol (Pyr) on the fragility of RBC were studied using NaCl-induced osmotic hemolysis. Hemoglobin level, plasma total antioxidant capacity (TAC), and nitrite levels were measured by spectrophotometric methods. Results Although the RBC hemolysis of all groups was not affected by L-arg and L-NMMA, the effect of DETA and DEA varied. The RBC fragility of old and young men was more sensitive to Pyr-induced oxidative stress than old and young women. Human RBC was differentially affected by nitrosative stress induced by Pyr10 −3 M plus varying concentrations of DETA and DEA depending on age and sex. While the plasma TAC values of the young men were higher than those of young women, there was no significant difference in plasma nitrite levels between all groups. Conclusions The findings of this study indicate that the fragility of human red blood cells (RBCs) in response to oxidative and nitrosative stress varies depending on sex and age.