An ex vivo study of nitric oxide efflux from human erythrocytes in both genders.

Introduction: Acetylcholinesterase (AChE) is located on outer surface of erythrocyte membrane. Gender-related differences in erythrocyte AChE enzyme activity had been verified in young adults. It is also known that binding of acetylcholine (ACh) with AChE on erythrocyte membrane initiates a signal transduction mechanism that stimulates nitric oxide (NO) efflux.
Aims: This ex vivo study was done to compare the amount of NO efflux obtained from erythrocytes of healthy donors in males and females.
Methods: We included 66 gender age-matched healthy donors (40-60 years old). We performed quantification of erythrocyte NO efflux from erythrocytes and of the membrane AChE enzyme activity.
Results: There are no significant differences in NO efflux from erythrocytes between men and women. Regarding AChE enzyme activity values, in this range of age, no differences between genders were obtained. However, the values of AChE enzyme activity in the third quartile of NO efflux values were significantly higher (p < 0.05) in women than in men.
Conclusions: The efflux of NO from erythrocyte of healthy humans did not change with gender. For the same range of values of NO efflux from erythrocytes, in both gender, it was verified higher values of AChE enzyme activity in women.