Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1986-9-17
pubmed:abstractText
The present studies were undertaken to examine the factors that influence the growth of cells of endocrine gland origin, particularly the possible interactions between "nonspecific" growth factors and the trophic hormone for a target endocrine cell. As a model system, we explored the individual and conjoint effects of insulin-like growth factor-I (IGF-I) and TSH on the growth of FRTL5 cells, a nontransformed line of cloned rat thyroid follicular epithelium. In these cells, IGF-I and TSH each produced a dose-dependent enhancement of DNA synthesis and cell proliferation. When added together, IGF-I and TSH were markedly synergistic in stimulating DNA synthesis, producing increases in 3H-thymidine incorporation that were far greater than the sum of the effects of each alone. A similar effect of IGF-I was evident in the case of the stimulation of DNA synthesis produced by immunoglobulin G (IgG) preparations from the blood of patients with Graves' disease. Such IgG bind to the TSH receptor and mimic the actions of TSH therein. It is suggested, therefore, that there exist in the FRTL5 cell line at least two mechanisms for the regulation of growth, one activated at the level of the IGF-I receptor and the other at the level of the TSH receptor. When the two pathways are activated concurrently, a synergistic enhancement of DNA synthesis takes place. The findings indicate that the FRTL5 cell line is an excellent model in which to study these complex interactions and that IGF-I may be a determinant of thyroid cell growth, both normally and in certain thyroid diseases.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0013-7227
pubmed:author
pubmed:issnType
Print
pubmed:volume
119
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
940-2
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1986
pubmed:articleTitle
Insulin-like growth factor-I stimulates the growth of rat thyroid cells in culture and synergizes the stimulation of DNA synthesis induced by TSH and Graves'-IgG.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.