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Biomedical subjects

I Simon-Schnass

Publications and source records attributed to I Simon-Schnass.

5 recordsLinked to original sources
PubMed1990

The influence of vitamin E on rheological parameters in high altitude mountaineers.

Vitamin E is a fat-soluble antioxidant which plays an important role in maintaining cells in a reduced state. Oxidation reactions can lead to damage of both endothelial cells and circulating blood cells and may thus influence the rheological conditions. A group of 13 mountaineers was selected as a model for persons at increased risk of oxidative stress. 6 subjects received 200 mg vitamin E twice daily for 4 weeks, and 7 subjects received placebo. Erythrocyte filterability, blood viscosity, changes in the blood picture, and three blood coagulation factors (antithrombin III, protein C, and fibrin monomers) were investigated. The baseline values (t1) were determined at 1.500 m, and after supplementation the investigations were repeated twice at 4.300 m (t2 und t3). There was a marked rise in the hematocrit in both groups during the ascent which was due to an increase not only of the erythrocytes but also of the leucocytes. This change was more pronounced in the control group. The erythrocyte filterability was unaltered in the vitamin E group in comparison with baseline but was significantly impaired in the control group. The changes in these two parameters-hematocrit and filterability--resulted in a significant higher blood viscosity. Furthermore in the control group, but not in the vitamin E group, a significant fall in the protein C activity was observed. The cause may be an additional release from degenerated leucocytes of various proteases which degrade protein C. A further possible cause is a derangement of metabolic reactions in the vascular endothelium. All these possible causes could be counteracted by the higher antioxidative potential of the verum group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Influence of vitamin E on physical performance.

There are two properties of vitamin E which are leading to its use for better physical performance. On one side it promotes an economical energy metabolism, on the other side it acts as a stabilizing antioxidant in membranes. One group of 6 high altitude mountain climbers was substituted with 2 x 200 mg dl-alpha-tocopheryl acetate and a second of 6 were given placebos during a 10 weeks expedition. The influence on the synthesis of lactic acid and on the exhalation of pentane was investigated. After 2 weeks the anaerobic threshold (AT) was higher in both groups. In the course of the experiment the AT of the treatment group increased further whereas the AT of the control group decreased significantly (p less than 0.01). Pentane exhalation, considered to be a measure for lipid peroxidation, showed no significant change after a 4 weeks substitution with vitamin E in the treatment group, but in the control group the exhaled pentane was more than 100% higher. The difference is significant, too (p less than 0.01). The results of this study show that vitamin E has a beneficial effect on physical performance and on cell protection, at least at high altitude.

Adult↗