Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1990-5-4
pubmed:abstractText
Cationic selena- and tellurapyrylium dyes 1d-g and 1i were found to inhibit cytochrome c oxidase upon irradiation of isolated mitochondrial suspensions treated with 10 microM solutions of dye. The amount of inhibition by these dyes was found to be related to oxygen concentration and inversely related to the concentration of added imidazole, a singlet-oxygen trap, suggesting that singlet oxygen is responsible, at least in part, for the inhibition of the enzyme. Dyes 1d-g and 1i, containing either selenium or tellurium, produce singlet oxygen with a quantum efficiency, phi (1O2), between 0.005 and 0.09 in methanol. Dyes 1a-c, containing the lighter chalcogens oxygen and sulfur, have values of phi (1O2) that are less than 0.0008 in methanol and do not inhibit cytochrome c oxidase in irradiated mitochondrial suspensions. Dyes 1c and 1d have nearly identical spectral and redox properties. Only the selenapyrylium dye 1d inhibits the enzyme, suggesting that neither ground-state nor excited-state electron transfer is important in inhibition of the enzyme. Electron micrographs of human U251 glioma cells, treated in vitro with 1i and light, showed pronounced morphology changes in the mitochondrial membranes relative to electron micrographs of untreated cells. Epifluorescence microscopy of the treated cells showed granular yellow-green fluorescence presumably from photooxidized dye in the mitochondria.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0022-2623
pubmed:author
pubmed:issnType
Print
pubmed:volume
33
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1108-16
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Chalcogenapyrylium dyes as photochemotherapeutic agents. 2. Tumor uptake, mitochondrial targeting, and singlet-oxygen-induced inhibition of cytochrome c oxidase.
pubmed:affiliation
Corporate Research Laboratories, Eastman Kodak Company, Rochester, New York 14650.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S.