Vitamin E in Vitro Action on Horse Red Blood Cell Membranes from Rest and Exercised Horses: Modulation of Membrane Fluidity and Glutathione Peroxidase Activity

Objectives: The intensive exercise increases circulating radical oxygen specie levels in humans. Horses are athletic animals that can be trained to execute performances well established by International Equestrian Federations. They are useful models to study their physical performances and related structural and metabolic derangements.

Methods: The animals were ten Arabian strain horses, 6-8 years old, trained for Cross country and six horses at rest. Blood samples are tested for Glutathione Pero-Xidase (GPX) and chemical parameters both before and after standard exercise. Membranes are tested for diphenylhexatriene fluorescence anisotropy in red blood cell membranes by Perrin plot.

Results: Glutathione peroxidase activity determined in exercised animals and radical oxygen species at rest and preand post-exercise significantly decrease after exercise with P: 0.008 by Student-T. The vitamin addition (50 µM) to red blood cell membranes brings the activity to reference level. Fluorescence anisotropy is abruptly worsened in erythrocyte membranes from exercised animals and almost restored after vitamin E treatment of membrane preparations and P > 0.05 by ANOVA.

Discussion: Erythrocyte membranes are damaged by standard exercise and both GPX and membrane fluorescence anisotropy (rs) is almost restored to reference and pre-exercise levels by in vitro treatment with vitamin E.