EFFECT OF A VITAMIN E AND SELENIUM ORAL SUPPLEMENTATION ON HEMATOLOGICAL PARAMETERS, MUSCULAR INJURIES MARKERS ENZYMES AND PEROXIDATION INDICES OF BIOMOLECULES IN SHOW JUMPING HORSES

Abstract

Among the main physiopathological mechanisms in the appearance of injuries related to the physical exercise, the involvement of free radicals is very important, mainly oxygen reactive species. They can lead to hematologicaland biochemical alterations related to injuries mediated by the physical effort. For the prevention and treatment of such conditions, the use of antioxidant supplementation, like ?-tocopherol (vitamin E) and selenium has been considered for training animals and competitions of high impact. The aim of this research was to evaluate the influence of vitamin E and selenium oral supplementation on hematological parameters, the seric activity of muscular enzymes and the level of substances derived from oxidative stress on erythrocyte membranes of horses normally trained and submitted to a show jumping test. For this purpose, 20 horses with these characteristics were divided in two groups. One of them (GT) received oral supplementation of vitamin E (2500 mg/day) and selenium (3 mg/day) for 45 days and another one was kept as control (GC). Both groups were submitted to a standardized test of show jumping and samples of blood were collected in rest, immediately after, and 6, 12 and 24 hours after the end of the activity. The constituents of the hemogram, the seric activity of enzymes CK, AST, and LDH, and the level of an oxidative stress marker (TBARS) in erythrocyte membranes were evaluated. The number of erythrocytes and leukocytes returned to basal levels in GT after 6 hours. In GC, such values returned to rest levels between 12 and 24 hours. Despite the observed differences in some hematological parameters dynamics between the two groups, it was not possible to determine antioxidant activity in GT. These observations demonstrate the need for more studies to understanding oxidative stress effects on athletics horses and the use of antioxidants for these animal’s diets.

KEY WORDS: Exercise, horse, oxidative stress, selenium, vitamin E.