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Constance Umbles

Bio: Constance Umbles is an academic researcher from Chicago State University. The author has contributed to research in topics: Superoxide dismutase & Copper deficiency. The author has an hindex of 1, co-authored 2 publications receiving 259 citations.

Papers
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Journal ArticleDOI
TL;DR: It appears likely that the observed decrease in SOD in young rats is caused indirectly by a lead-induced copper deficiency rather than by a direct inhibitory effect of lead.

287 citations

Book ChapterDOI
01 Jan 1987
TL;DR: The catalytic activity of CuSOD is inhibited by cyanide and this property is used to distinguish it from MnSOD.
Abstract: Superoxide dismutase (SOD) is considered to have an important role in protecting cells against direct and indirect oxidative damage1–3. Total SOD activity is the result of the activities of a copper dependent enzyme (CuSOD), present primarily in the cytoplasm, and a manganese dependent enzyme(MnSOD), localized in the mitochondrial matrix4 The catalytic activity of CuSOD is inhibited by cyanide and this property is used to distinguish it from MnSOD.5

Cited by
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01 Jan 2000
TL;DR: In this paper, the importance of using antioxidants in treating lead poisoning was discussed, and the possible protective effects of antioxidants in lead toxicity were investigated. But, the authors did not consider the effect of antioxidant supplementation following lead exposure.
Abstract: Recent studies have shown that lead causes oxidative stress by inducing the generation of reactive oxygen species, reducing the antioxidant defense system of cells via depleting glutathione, inhibiting sulfhydryl-dependent enzymes, interfering with some essential metals needed for antioxidant enzyme activities, and/or increasing susceptibility of cells to oxidative attack by altering the membrane integrity and fatty acid composition. Consequently, it is plausible that impaired oxidant/antioxidant balance can be partially responsible for the toxic effects of lead. Where enhanced oxidative stress contributes to lead-induced toxicity, restoration of a cell's antioxidant capacity appears to provide a partial remedy. Several studies are underway to determine the effect of antioxidant supplementation following lead exposure. Data suggest that antioxidants may play an important role in abating some hazards of lead. To explain the importance of using antioxidants in treating lead poisoning the following topics are addressed: (i) Oxidative damage caused by lead poisoning; (ii) conventional treatment of lead poisoning and its side effects; and (iii) possible protective effects of antioxidants in lead toxicity.

536 citations

Journal ArticleDOI
TL;DR: Data suggest that antioxidants may play an important role in abating some hazards of lead, and that restoration of a cell's antioxidant capacity appears to provide a partial remedy.

524 citations

Journal ArticleDOI
TL;DR: In this article, a review on mechanisms for lead-induced oxidative stress and relevance of oxidative stress to lead-related human disease with low lead exposure is presented, where the authors focus on mechanisms of lead toxicity and its effects on membranes, DNA and antioxidant defense systems of cells.

352 citations

01 Jan 2007
TL;DR: The present review focuses on mechanisms for lead-induced oxidative stress and relevance of oxidative stress to lead-related human disease with low lead exposure.
Abstract: Lead continues to pose a serious threat to the health of many children as well as adults. Concern about lead exposure as a significant public health problem has increased as evidence has mounted regarding adverse health effects at successively lower levels. This issue is complicated by the fact that there is no demonstrated biological function of lead in human. Lead potentially induces oxidative stress and evidence is accumulating to support the role of oxidative stress in the pathophysiology of lead toxicity. Lead is capable of inducing oxidative damage to brain, heart, kidneys, and reproductive organs. The mechanisms for lead-induced oxidative stress include the effects of lead on membranes, DNA, and antioxidant defense systems of cells. Recent epidemiological and toxicological studies have reported that lead exposure causes several diseases including hypertension, kidney disease, neurodegenerative disease and cognitive impairment. Although all these diseases include components of oxidative stress, the relevance of oxidative stress to lead-related diseases with low lead exposure has been criticized because most of the mechanistic studies have been conducted at moderate to higher dose levels. The association between low level lead exposure and oxidative stress has not been explored systematically. The present review focuses on mechanisms for lead-induced oxidative stress and relevance of oxidative stress to lead-related human disease with low lead exposure. © 2007 Elsevier B.V. All rights reserved.

336 citations

Journal ArticleDOI
TL;DR: It appears from the results that lead may exert its neurotoxic effects via peroxidative damage to the membranes in the different regions of the brain.
Abstract: We have investigated the effect of lead exposure on lipid peroxidation, a deteriorative process of the membranes, in the different regions of the brain. Lead treatment (50 mg/kg b.wt. intragastrically) for a period of eight weeks to rats resulted in a significant accumulation of lead in all the regions of brain, at maximum in hippocampus. The lipid peroxidation was accentuated following lead exposure and there was a linear correlation between the increase in lipid peroxidation and increase in lead levels (r = 0.75). The antioxidant capacity of the neuronal cells in terms of the activity of antioxidant enzymes superoxide dismutase, catalase and glutathione peroxidase was diminished. Lead treatment also altered the glutathione status i.e. levels of reduced glutathione were lowered, accompanied with the accumulation of oxidized glutathione. Furthermore, the activity of glutathione reductase was significantly lowered in lead-treated animals. The activity of membrane bound enzyme acetylcholinesterase was significantly inhibited following lead exposure and there was a linear correlation between the increase in lipid peroxidation and decrease in acetylcholinesterase activity (r = -0.83). It appears from the results that lead may exert its neurotoxic effects via peroxidative damage to the membranes.

214 citations