Linked Life Data

6335498

Source:http://linkedlifedata.com/resource/pubmed/id/6335498

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1985-3-26
pubmed:abstractText
Using Chinese hamster V79 cells in vitro a study has been made of the radiosensitizing properties of 4- or 5-nitroimidazoles substituted in the 2, 5 or 4 position with various halo, sulphur ether, sulphonamide, sulphonate, ether or nitro groups. Values of E17 (the one-electron reduction potential measured versus the normal hydrogen electrode at pH7) vary in the range -178 to -565 mV. All the compounds, with one exception, are more efficient radiosensitizers than would be predicted from their redox potentials, and the factor, C1.6/C1.6, by which a compound is more efficient has been calculated. The second-order rate constants, k2, for reaction of these nitroimidazoles with glutathione and/or dithiothreitol were determined. Within each class of nitroimidazole there is a trend for k2 to increase with increasing redox potential. However, there is no clear trend between k2 and C1.6/C1.6. The concentration required to cause a 50 per cent depletion of intracellular glutathione was determined for selected compounds, as was the ability of glutathione-S-transferase to catalyse reaction with thiols. These observations suggested that the relative thiol reactivity measured under chemically controlled conditions does not necessarily indicate thiol reactivity intracellularly. Studies using the MT tumour in mice showed that the high levels of radiosensitization seen in vitro could not be duplicated in vivo. This was attributed to thiol reactivity, resulting in low metabolic stability and rapid depletion of sensitizer in vivo.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0020-7616
pubmed:author
pubmed:issnType
Print
pubmed:volume
46
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
731-45
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1984
pubmed:articleTitle
Thiol reactive nitroimidazoles: radiosensitization studies in vitro and in vivo.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't