Lack of ameliorative effect of Vitamins E and C supplements to oxidative stress and erythrocytes deterioration after exhaustive exercise at high altitude in native rats
The purpose of this study was first, to determine the effects of acute forced swimming to exhaustion, by native rats at high altitude, on some hematological and biochemical parameters and on lipid peroxidation and cell anti-oxidant system in red blood cells of these rats. Secondly, to investigate any protective effect conferred by Vitamins E and C pre-co treatment. Young male Wistar rats weighing 150 to 160 g (aged three to four months) were used in this study. All rats were from the same lineage and were born in the high altitude environment (2,800 m), and were from the 10th generation whose parents lived in the high altitude area for six months. The rats were divided into two groups: non-stressed group (n = 6) used as the control, and stressed group (n = 12). The non-stressed group was given normal saline intraperitoneally (i.p.) and was not exercised. The stressed group was divided into two subgroups, each consisting of six rats, classified as stressed group 1 (given normal saline) and stressed group 2 (given Vitamins E and C supplements). All rats in the stressed group were exposed to acute forced swimming exercise to exhaustion. Blood samples were collected at the end of the experimental procedure from all groups for routine hematological analysis and for determination of serum total bilirubin and iron. Red blood cell (RBC) levels of thiobarbituric acid reactive substances (TBARS), superoxide dismutase (SOD), catalase (CAT), and reduced glutathione (GSH) were also determined. Acute forced exhaustive swimming caused significant decreases in erythrocyte count, hemoglobin (Hb) concentration, and packed cell volume (PCV) with no changes in mean corpuscular volume (MCV), mean cell hemoglobin (MCH), and mean cell hemoglobin concentration (MCHC) but with significant increases in the levels of serum total bilirubin and iron. Exhaustive exercise also caused a significant increase in TBARS level, and significant decreases in the activities of SOD and CAT and in GSH level. With the exception of CAT, pre-treatment with Vitamins E and C supplements did not produce any significant improvement in the levels of these hematological and biochemical parameters. In conclusion, single forced exhaustive swimming exercise at high altitude resulted in elevation of oxidative stress and deterioration of erythrocyte structure (hemolysis) in native rats which were not ameliorated by antioxidant Vitamins E and C co-treatment.
Key words: Exercise, oxidative stress, Vitamins E, C and erythrocytes.