Linked Life Data

3787463

Source:http://linkedlifedata.com/resource/pubmed/id/3787463

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1986-12-29
pubmed:abstractText
Radiation treatment of Long-Evans male rats (40 mu Ci Na131I at the age of 2 months) led to a high incidence of thyroid follicular carcinomas at the age of 24 months; castration of males before irradiation caused a significant reduction in incidence of this tumor. In this study, replacement testosterone (T) was administered to castrated male rats by means of implanted, slow-release hormone-containing pellets (T-physiologic dose). Three testosterone doses (0.1T, 1.0T, and 30T) were used to treat groups of castrated irradiated and castrated nonirradiated rats from 2 to 18 months of age. The incidence of thyroid follicular carcinoma at 18 months in irradiated rats depended on the dose of replacement testosterone used. Tumor incidence was 8%, 14%, 41%, and 50% after treatment with 0T, 0.1T, 1.0T, and 30T, respectively. The incidence of thyroid follicular carcinoma in nonirradiated rats ranged from 0 to 7%. Mean serum thyroid-stimulating hormone (TSH) values in irradiated animal groups were elevated significantly above those for age-matched nonirradiated animals. The degree of TSH elevation in irradiated animals was related directly to the testosterone-replacement level. All rat groups showed age-dependent decreases in serum T4 levels, and T4 levels were also lowered by replacement testosterone in nonirradiated castrated animals. In aging irradiated animals, serum T4 levels were similarly decreased by testosterone, despite elevated TSH levels in these groups. In this study, testosterone appeared to act indirectly to promote development of irradiation-induced thyroid tumors by early and prolonged elevation of TSH levels.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0039-6060
pubmed:author
pubmed:issnType
Print
pubmed:volume
100
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1078-87
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1986
pubmed:articleTitle
Testosterone enhancement of thyroid carcinoma in rats: the role of TSH.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't