Linked Life Data

9028385

Source:http://linkedlifedata.com/resource/pubmed/id/9028385

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1997-3-4
pubmed:abstractText
The purpose of this work was to determine the hormone dependence of mammary tumors induced in Sprague-Dawley rats by three intraperitoneal injections of N-nitroso-N-methylurea at 50, 80, and 110 days of age. Two experimental designs were carried out: (a) Ten days before the first NMU injection, 130 rats were divided into 13 batches and randomly assigned to the following treatments: control, ovariectomy (OVX), tamoxifen (TAM), bromocriptine (BROM), haloperidol (HAL), estradiol (E2), progesterone (Pg), OVX + BROM, TAM + BROM, OVX + HAL, TAM + HAL, OVX + TAM, and E2 + BROM. After 150 days of treatment the following growth parameters were determined: latency period (LP), mean tumor number per rat (n/t), and tumor incidence (TI). LP was significantly increased (p < 0.05) only by Pg and TAM + BROM. The n/t was significantly decreased (p < 0.05) by all treatments except HAL. TI was significantly reduced by OVX, TAM, BROM, and their combinations, (b) Rats bearing ip-NMU-induced mammary tumors were divided into 7 batches and assigned to the following treatments: control, OVX, TAM, BROM, HAL, OVX + BROM, and TAM + BROM. Tumor growth was assessed up to 60 days of treatment; only OVX, TAM and their combination with BROM were able to produce tumor regression. These results support the essential role of E2 and prolactin in the promotion stage of carcinogenesis. However, for established tumors, growth becomes more independent from hormone influence, in particular from prolactin deprivation. We conclude that this model seems suitable for studying the mechanisms underlying the evasion of hormonal control of tumor growth.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0735-7907
pubmed:author
pubmed:issnType
Print
pubmed:volume
15
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
8-17
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Hormone dependence of mammary tumors induced in rats by intraperitoneal NMU injection.
pubmed:affiliation
Laboratorio de Radioisótopos, Cátedra de Física, Facultad de Farmacia y Bioquimica, Universidad de Buenos Aires, República Argentina.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't