Linked Life Data

10590223

Source:http://linkedlifedata.com/resource/pubmed/id/10590223

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
2000-2-11
pubmed:abstractText
Previous studies have suggested that liver cell proliferation is fundamental for the growth of carcinogen-initiated cells. To gain further information on the association between cell proliferation and hepatocarcinogenesis, we have examined the effect of the hormone 3,3',5-triiodo-L-thyronine (T3), a strong liver mitogen, on the growth of diethylnitrosamine (DENA)-induced hepatic lesions positive for the placental form of glutathione S-transferase (GSTP). Two weeks after a single initiating dose of DENA (150 mg/kg), cycles of liver cell proliferation were induced in male Fischer rats by feeding a T3-supplemented diet (4 mg/kg) 1 week/month for 7 months. Rats were killed at the end of the seventh cycle or 1 month later. Results indicate that, in spite of an increased labelling index, a 70% reduction in the number/cm(2) of GSTP-positive minifoci occurred in T3-treated rats. A decrease in the number of GSTP-positive foci was also observed in T3-treated rats killed 1 month after the last exposure to the hormone (40, versus 67 foci/cm(2) in controls), indicating that the reduction was not due to an inhibitory effect on GSTP exerted by the concomitant presence of T3. In a second series of experiments where DENA-treated rats were fed T3 for 1 week and then subjected to the resistant hepatocyte (RH) model, it was found that T3 treatment prior to promotion resulted in a decrease in the number of GSTP-positive foci (16 GSTP(+) foci/cm(2) in T3-fed animals versus 45 in the control group). The results indicate that cell proliferation associated with T3 treatment: (i) reduces the number of carcinogen-induced GSTP-positive lesions; (ii) does not exert any differential effect on the growth of the remaining foci; (iii) inhibits the capacity of putative DENA-initiated cells to be promoted by the RH model. Data suggest that cell proliferation may not necessarily represent a stimulus for the growth of putative preneoplastic lesions.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0143-3334
pubmed:author
pubmed:issnType
Print
pubmed:volume
20
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2299-304
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Cell proliferation induced by 3,3',5-triiodo-L-thyronine is associated with a reduction in the number of preneoplastic hepatic lesions.
pubmed:affiliation
Dipartimento di Tossicologia, Sezione di Oncologia e Patologia Molecolare, Via Porcell 4, 09124 Cagliari, Italy. gmledda@vaxca1.unica.it
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't