Linked Life Data

8481405

Source:http://linkedlifedata.com/resource/pubmed/id/8481405

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1993-6-3
pubmed:abstractText
Historically, it has been theorized that the enhanced oxidant sensitivity of glucose-6-phosphate dehydrogenase (G6PD)-deficient erythrocytes arises as a direct consequence of an inability to maintain cellular glutathione (GSH) levels. This study alternatively hypothesizes that decreased NADPH concentration leads to impaired catalase activity which, in turn, underlies the observed oxidant susceptibility. To investigate this hypothesis, normal and G6PD-deficient erythrocytes and hemolysates were challenged with a H2O2-generating agent. The results of this study demonstrated that catalase activity was severely impaired upon H2O2 challenge in the G6PD-deficient cell while only a transient decrease was observed in normal cells. Supplementation of either normal or G6PD-deficient hemolysates with purified NADPH was found to significantly (P < 0.001) inhibit catalase inactivation upon oxidant challenge while addition of NADP+ had no effect. Analysis of these results demonstrated direct correlation between NADPH concentration and catalase activity (r = 0.881) and an inverse correlation between catalase activity and erythrocyte oxidant sensitivity (r = 0.906). In contrast, no correlation was found to exist between glutathione concentration (r = 0.170) and oxidant sensitivity. Analysis of NADPH/NADPt ratio in acatalasemic mouse erythrocytes demonstrated that NADPH maintenance alone was not sufficient to explain oxidant resistance, and that catalase activity was required. This study supports the hypothesis that impaired catalase activity underlies the enhanced oxidant sensitivity of G6PD-deficient erythrocytes and elucidates the importance of NADPH in the maintenance of normal catalase activity.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
30
pubmed:volume
1181
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
163-8
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Decreased catalase activity is the underlying mechanism of oxidant susceptibility in glucose-6-phosphate dehydrogenase-deficient erythrocytes.
pubmed:affiliation
Children's Hospital Oakland Research Institute, CA 94609.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't