Linked Life Data

6231099

Source:http://linkedlifedata.com/resource/pubmed/id/6231099

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1984-5-4
pubmed:abstractText
The photosensitizing activity of hematoporphyrin derivative (HPD) was investigated by studying selected enzymes localized to mitochondria and cytosol of R3230AC mammary adenocarcinomas. Experiments in vitro demonstrated that mitochondrial succinate dehydrogenase was inhibited in a drug dose- and light exposure time-related manner; at 7.0 micrograms of HPD per ml or higher, enzyme activity was inhibited greater than 50% after 15 min of photoradiation. The three cytosol enzymes studied under the same conditions in vitro demonstrated different photosensitivities. Pyruvate kinase activity was significantly inhibited in a dose- and time-related fashion, whereas lactate dehydrogenase was inhibited to a lesser extent, and glucose phosphate isomerase activity was inhibited only at the highest dose (70 micrograms of HPD per ml) used. The time-course of these responses was examined with an in vivo-in vitro protocol, consisting of photoradiation of mitochondria and cytosol prepared from tumors obtained at various times (up to 1 week) after a single injection of HPD (80 mg/kg). Pyruvate kinase activity was markedly inhibited at early times returning to initial levels by 48 hr; neither lactate dehydrogenase nor glucose phosphate isomerase was inhibited by this treatment. Mitochondrial succinate dehydrogenase and cytochrome c oxidase activities displayed significant photoradiation-induced inhibitions, with greatest inhibition occurring between 24 and 96 hr after injection of HPD; at 1 week, succinate dehydrogenase activity had returned to its initial level, but cytochrome c oxidase activity remained significantly inhibited. These data suggest that HPD-induced photosensitization of mitochondria may be an important site of action contributing to tumor cell cytotoxicity and regression as a result of photoradiation therapy.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0008-5472
pubmed:author
pubmed:issnType
Print
pubmed:volume
44
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1483-8
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1984
pubmed:articleTitle
Hematoporphyrin derivative-induced photosensitivity of mitochondrial succinate dehydrogenase and selected cytosolic enzymes of R3230AC mammary adenocarcinomas of rats.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't