Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P30044 (antioxidant enzyme)
 8,037 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The purpose of this research was to evaluate the effect of age on protective antioxidant enzyme activity of normal fresh cadaver human retina of the macula and periphery. Antioxidant enzymes were assayed in tissue extracts generated from 5 mm trephined punches of retina obtained centered over the macula and the superior midperiphery of normal fresh human cadaver retina. Cadaver tissue was obtained from donors of a wide age range (age 7 to 85 years). The assays were performed within 6 h of enucleation and within 24 h of donor death. Antioxidant enzymes assayed included superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase. Hexokinase and glucose-6-phosphate dehydrogenase, enzymes not directly involved in protection against oxidative damage, were assayed for comparison. Enzyme specific activities were calculated for the macula and periphery using protein concentration of the extract as the denominator. Using linear regression analysis, over the age range of 25 to 75 years, superoxide dismutase activity of the periphery but not the macula tended to decline with age (p = 0.04, R2 = 0.21). Interindividual variability was high, and variability increased with age. The difference between the macular and peripheral enzyme activities for glutathione peroxidase tended to decline with increasing donor age (p = 0.025, R2 = 0.33). There was no effect of age on the specific activities of catalase, glucose-6-phosphate dehydrogenase, and glutathione reductase. The specific activity of hexokinase from the macula declined with increasing donor age (p = 0.022, R2 = 0.43). Time from death to enucleation or beginning of experiment was not a significant factor. In summary, age does not have an effect on the activity of major antioxidant enzymes of the macula in normal human retina. There is a tendency for an effect of age on peripheral superoxide dismutase activity and the difference between macular and peripheral glutathione peroxidase activity. High interindividual variability of antioxidant enzyme activity exists in humans.
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PMID:Antioxidant enzymes of the human retina: effect of age on enzyme activity of macula and periphery. 865 7

A transition zone between well-perfused proximal tissue and inadequately perfused distal tissue was evaluated histologically and biochemically in skin flaps. Cranially based pedicle flaps, 3 x 7.5 cm, were made on the backs of female Sprague-Dawley rats. Flap survival was 22% of the original flap area at 7 days and 40% at 14 days after flap elevation (p < 0.001). The transition zone consisted of full-thickness skin survival proximally and partial-thickness wound distally. It is evident that skin wounds induced by ischemia or reperfusion repair continuously between 7 and 14 days after flap elevation. Tissue glucose, lactate, and hypoxanthine levels were measured to assess capillary perfusion in the transition zone on postoperative day 3. The proximal full-thickness skin 5 mm from the wound margin demonstrated no significant changes in glucose and lactate levels compared with normal skin. The partial-thickness wounds exhibited no change in glucose (a 33% decrease was not statistically significant) but a significant increase (319% of normal) in lactate level (p < 0.05). Hypoxanthine levels increased to 453% of normal in full-thickness skin (p < 0.01) and to 787% in partial-thickness wounds (p < 0.001). Metabolic response was evaluated by enzyme assays in the transition zone. Hexokinase activity increased by 251% of normal (p < 0.05), glucose 6-phosphate dehydrogenase by 245% (p < 0.01), and glutathione reductase by 184% (p < 0.05) in the proximal full-thickness skin. Hexokinase activity further increased by 482% of normal (p < 0.01), glucose 6-phosphate dehydrogenase by 379% (p < 0.05), and glutathione reductase by 346% (p < 0.01) in partial-thickness wounds. The results suggest that partial-thickness wounds have less capillary circulation but greater antioxidant enzyme activities than does the survival area with full-thickness skin.
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PMID:Microanalyses of enzymes and metabolites in ischemia/reperfusion-induced partial-thickness skin wounds. 1716 2