Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2001-3-27
pubmed:abstractText
The prevalence of liver tumors throughout the world makes it imperative to seek chemopreventive agents. This tumor appears to be hormone-responsive and hormonal manipulations may therefore be beneficial. On this basis, both sexes of 12-day-old B6C3F(1) mice were injected i.p. with diethylnitrosamine (DEN) at the dose of 2.5 mg / g body weight and observed for 32 weeks (males) or 36 weeks (females). In 100% of male mice, liver tumors were observed with an average diameter of 2.72 mm and multiplicity of 60.8. Orchidectomy at 6 weeks of age in these mice inhibited the incidence, multiplicity and size to 63%, 5.6 and 1.54 mm, respectively. By further implantation with an E(2) pellet at monthly intervals, these parameters were reduced to 26%, 0.6 and 0.61 mm, respectively. Administration of a gonadotropin-blocking chemical, leuprorelin, to DEN-treated male mice significantly reduced the multiplicity and size of tumors to 18.3 and 2.54 mm (P < 0.01 compared to those of DEN only). In female mice, the incidence of liver tumor was significantly smaller than that of males. However, ovariectomy and / or testosterone supplement significantly increased the occurrence of liver tumor. An anti-estrogen, toremifene, caused a marked further decrease of liver tumors. Mitotic indices with bromodeoxyuridine in tumor tissues paralleled the occurrence of liver tumors. Serum testosterone levels were significantly reduced by orchidectomy or by leuprorelin administration. These results further confirm that liver tumor is testosterone-responsive and hormonal manipulation by surgical orchidectomy or by chemical orchidectomy i.e. by leuprorelin, could substantially prevent the appearance of liver tumors.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0910-5050
pubmed:author
pubmed:issnType
Print
pubmed:volume
92
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
249-56
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Sex hormone dependency of diethylnitrosamine-induced liver tumors in mice and chemoprevention by leuprorelin.
pubmed:affiliation
Department of Cancer Research, Research Institute for Radiation Biology, Hiroshima University School of Medicine, Minami-ku, Hiroshima 734-8553, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't