Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P36969 (phospholipid hydroperoxide glutathione peroxidase)
 344 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The importance of nutrition in protecting the living organism against the potentially lethal effects of reactive oxygen species and toxic environmental chemicals has recently been realized. This new perspective has prompted re-evaluation of the food constituents of human diet from the point of view of their nutritional adequacy, deficiency and toxicity. The biological antioxidant defense system is an integrated array of enzymes, antioxidants and free radical scavengers. These include glutathione reductase, glutathione-s-transferase, glutathione peroxidase, phospholipid hydroperoxide glutathione peroxidase, superoxide dismutase (SOD) and catalase, together with the antioxidant vitamins C, E and A. The individual components of this system get utilized in various physiological process and for chemoprotection and therefore require replenishment from the diet. Other components of the diet like carbohydrates, proteins and lipids are important for maintaining the levels of various enzymes required in body's defense system providing protection against carcinogens. However, the emerging newer concepts focus on the role of trace elements and other dietary components in antioxidant defense and detoxification mechanisms. Trace elements like Iron, zinc magnesium, selenium, copper, and manganese are some of the elements involved in antioxidant defense mechanisms. Inadequate intake of these nutrients has been associated with ischemic heart disease, arthritis, stroke and cancer, where pathogenic role of free radicals is suggested. Further the importance of diet in the prevention of chemical induced toxicity can not be undetermined. Recent reports on the role of bioflavonoids as antioxidents and their potential use to reduce the risks of coronary heart disease and cancer in human beings have opened a new arena for future research. Induction of the cytochrome P450 isoenzymes by food pyrolysis, mutagens, alcohol and fasting, on the other hand is reported to contribute to chemical toxicity and carcinogenecity. Certain chemicals moieties in the food are mutagenic and carcinogenic.
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PMID:Role of nutrition in toxic injury. 1064 Nov 28

In the sperm nuclei, of mammalian species selenium has been found only in the form of sperm nuclei glutathione peroxidase (snGPx) where it is most likely bound to the chromatin of spermatozoa. Over 80% of selenium in sperm is bound to the selenoprotein phospholipid hydroperoxide glutathione peroxidase (PHGPx) in the midpiece of rat sperm. Zinc in sperm is mainly contained in the outer dense fiber (ODF) proteins of the flagella of mammalian spermatozoa. In the sperm nuclei, zinc is predominately located in the chromatin to the protamine proteins. In order to investigate if the insertion of zinc and selenium in sperm chromatin is regulated, the element concentrations were determined in equine spermatozoa and purified sperm nuclei. We found a significant positive correlation between the selenium concentration in equine spermatozoa and sperm nuclei. The same finding was obtained for the zinc concentration in spermatozoa and sperm nuclei. The results assume that the distribution of selenium and zinc in spermatozoa is regulated by cell signaling pathways and in this way determining the selenium and zinc amount in the chromatin of spermatozoa.
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PMID:Is the distribution of selenium and zinc in the sublocations of spermatozoa regulated? 1740 33

Antioxidants in the male reproductive tract are the main defence factors against oxidative stress caused by reactive oxygen species production, which compromises sperm function and male fertility. This study was designed to determine the activity of antioxidant enzymes, such as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), in the testicular and epididymidal tissues of adult male European bison (Bison bonasus). The reproductive tract tissues were subjected to real-time reverse transcriptase-polymerase chain reaction (RT-PCR) analysis to quantify mRNA expression levels of five antioxidant enzymes: copper/zinc SOD (Cu/Zn SOD), secretory extracellular SOD (Ec-SOD), CAT, phospholipid hydroperoxide glutathione peroxidase (PHGPx) and GPx5. The corpus and cauda epididymidal tissues displayed greater (p < 0.05) SOD activity compared with the testicular tissue. It was found that CAT activity was lowest (p < 0.05) in the cauda epididymidis, whereas negligible GPx activity was detected in the reproductive tract tissues. There were no detectable differences in the mRNA expression level of Cu/Zn SOD among the different reproductive tract tissues. Small amounts of Ec-SOD mRNA were found in the reproductive tract, particularly in the epididymides. The caput and cauda epididymides exhibited greater (p < 0.05) level of CAT mRNA expression, whereas PHGPx mRNA was more (p < 0.05) expressed in the testis. Furthermore, extremely large amounts of GPx5 mRNA were detected in the caput epididymidal tissue compared with other tissues of the reproductive tract. It can be suggested that the activity of the antioxidant enzymes and the relative gene expression of the enzymes confirm the presence of tissue-specific antioxidant defence systems in the bison reproductive tract, which are required for spermatogenesis, epididymal maturation and storage of spermatozoa.
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PMID:Antioxidant enzyme activity and mRNA expression in reproductive tract of adult male European Bison (Bison bonasus, Linnaeus 1758). 2245 32