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Query: UMLS:C0042875 (vitamin E deficiency)
 916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Oxidative damage and the role of antioxidants and prooxidants in aerobic metabolism is of great current interest; it spans areas of research such as carcinogenesis, ageing, toxicology and nutrition. We have used Bantin-Kingman female rats for both in vivo and in vitro studies. In these animals we have altered the levels of all-rac-alpha-tocopherol (vitamin E) by dietary means and have used physical exercise and visible light exposure to alter oxidative stress. Our results show a progressive and specific increase in the susceptibility of many subcellular membranes to oxidative damage with increasing levels of vitamin E deficiency and/or physical stress. In addition, endurance training raised the levels of antioxidative enzymic pathways in both skeletal and cardiac muscle.
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PMID:Vitamin E, physical exercise and tissue oxidative damage. 655 8

Using the dimethylbenz[a]anthracene-induced mammary tumor model, the present study demonstrated that a low vitamin E intake (7.5 mg/kg of diet) had minimal effect on carcinoma development in rats fed a 5% stripped corn oil diet, but resulted in a marked enhancement in tumor incidence and yield in those rats fed a 25% stripped corn oil ration. Control animals in this experiment received an adequate supply of vitamin E (30 mg/kg as DL-alpha-tocopheryl acetate). Thus, the effect of vitamin E deficiency on mammary carcinogenesis was accentuated in rats maintained on a high polyunsaturated fat diet, an observation similar to that of selenium deficiency which was reported by the author in a previous publication. In view of the biochemical interaction between vitamin E and selenium as endogenous antioxidants, another experiment was conducted to determine whether supranutritional supplementation of vitamin E (1000 mg/kg) was able to block the enhancement in mammary tumorigenesis due to selenium deprivation. Results of this experiment indicated that vitamin E excess failed to overcome the augmented tumor yield in selenium-deficient rats, nor did it provide any protection in rats that received an adequate supply of selenium. In summary, vitamin E deficiency may increase the risk of neoplastic development, especially when coupled with a high polyunsaturated fat intake; however, a high vitamin E supplementation does not seem to have any prophylactic effect on tumorigenesis by itself.
Carcinogenesis 1982
PMID:Dietary vitamin E intake and mammary carcinogenesis in rats. 681 42

Using a subtraction-enhanced display technique, we identified a rodent alpha-tocopherol transfer protein (alpha-TTP) cDNA which exhibited markedly lower messenger RNA (mRNA) amounts in rat hepatocellular carcinoma (HCC) than in healthy controls. Several lines of evidence have substantiated that abnormal alpha-TTP results in isolated vitamin E deficiency. In this study, we investigated the hepatic mRNA amounts of alpha-TTP during rat hepatic carcinogenesis and liver regeneration on Northern blot, localization of alpha-TTP mRNA in HCC of rats and humans by in situ hybridization, and we analyzed the correlation between alpha-TTP mRNA and alpha-tocopherol. alpha-TTP mRNA concentrations of the rats were decreased at the early stage of hepatic carcinogenesis, and remained 3-5-fold reduced as the tumor progressed. In parallel, serum alpha-tocopherol concentrations were significantly decreased to 40% of those in the controls at the early stages of rat hepatic carcinogenesis (p < 0.01). The 2 data sets were strongly correlated (r = 0.834, p < 0.001). In situ hybridization revealed that a decrease of alpha-TTP mRNA was preferentially localized in the tumor nodules of rats and humans with HCC. Our data suggest that repressed transcription of alpha-TTP is associated with a decrease of serum alpha-tocopherol and with hepatic carcinogenesis.
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PMID:Correlation of repressed transcription of alpha-tocopherol transfer protein with serum alpha-tocopherol during hepatocarcinogenesis. 917 27

Vitamin E is the most important chain-breaking, lipid-soluble antioxidant present in body tissues of all cells and is considered the first line of defense against lipid peroxidation and it is important for normal function of the immune cells. However, vitamin E deficiency is rare in well-nourished healthy subjects and is not a problem, even among people living on relatively poor diets, both T- and B-cell functions are impaired by vitamin E deficiency. While immune cells are particularly enriched in vitamin E because of their high polyunsaturated fatty acid content, this point puts them at especially high risk for oxidative damage. Besides its immunomodulatory effects, vitamin E also plays an important role in carcinogenesis with its antioxidant properties against cancer, and ischemic heart disease with limiting the progression of atherosclerosis. Supplementation of vitamin E significantly enhances both cell mediated and humoral immune functions in humans, especially in the elderly and animals.
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PMID:Vitamin E and immunity. 2141 72