Effect of vitamin E supplementation on post-exercise plasma lipid peroxidation and blood antioxidant status in smokers: with special reference to haemoconcentration effect

The oxidative effects were investigated of exhausting exercise in smokers, and the possible protective role of 400 mg.day(-1) vitamin E (Vit E) supple mentation over a period of 28 days. The subjects exercised to exhaustion in cluding concentric-eccentric contractions following maximal cycling. The ha ematocrit and haemoglobin, leucocyte (WBC), plasma lactic acid (La) and mal ondialdehyde (MDA), erythrocyte superoxide dismutase (SOD) and glutathione peroxidase (GPx), serum Vit E and ceruloplasmin (CER) concentrations were m easured pre and post exercise. Supplementation increased Vit E concentratio ns 28% and 31% in the controls and the smokers, respectively. Cigarette smo king and/or Vit E supplementation did not influence plasma lipid peroxidati on or the antioxidant status at rest. Exercise caused significant haemoconc entration in all groups. When the post-exercise concentrations were adjuste d for haemoconcentration, a significant elevation in La concentrations due to exercise was observed in all groups. Similarly, there were significant e levations in the adjusted WBC counts in all groups except the Vit E supplem ented controls. The MDA concentrations on the other hand, when adjusted for haemoconcentration, did not exhibit any difference due to exercise. Exerci se did not affect the GPx and CER activities either, while causing a SOD ac tivity loss in all groups except the Vit E supplemented non-smokers. Serum Vit E concentrations diminished significantly in all groups after exercise. Postexercise plasma MDA and blood antioxidant concentrations were not alte red by smoking. The results would suggest that plasma volume changes should always be taken into account when assessing post-exercise plasma concentra tions and that smoking and exercise do not have an additional collective ef fect on plasma lipid peroxidation and the dose of Vit E administered was in sufficient to maintain the serum concentrations after exercise.