Linked Life Data

3372685

Source:http://linkedlifedata.com/resource/pubmed/id/3372685

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1988-6-28
pubmed:abstractText
Insulin-like growth factor I (IGF-I) is one of a number of mitogenic factors in the serum of animals and humans. We demonstrated previously that IGF-I is a potent mitogen for FRTL5 cells, a line of rat thyroid follicular cells. In this study, we assessed the relevance of this finding with respect to the levels of IGF-I found in human serum by comparing the effects of normal serum and serum from patients with untreated acromegaly or hypopituitarism on DNA synthesis in quiescent FRTL5 cells. As expected, when added to cells maintained in Coon's modified Ham's F-12 medium containing 0.1% BSA, but devoid of insulin, transferrin, TSH, or calf serum, normal serum produced a dose-dependent stimulation of [3H]thymidine incorporation into DNA. A similar, but more marked, effect was produced by the addition of serum from patients with untreated acromegaly. In multiple experiments, a standard concentration (0.5%) of acromegaly serum was more stimulatory to DNA synthesis than was normal serum. In a single experiment designed to eliminate interassay variation and define the relationship between the ability of serum to stimulate DNA synthesis and its IGF-I concentration, studies were performed with 0.5% concentrations of serum from 9 normal subjects, 15 patients with untreated acromegaly, and 3 patients with panhypopituitarism. On the average, [3H]thymidine incorporation in the presence of serum from patients with acromegaly was approximately 3 times, and that in the presence of serum from patients with hypopituitarism only one fourth, that in the presence of serum from normal subjects; there was no overlap of individual values in the three groups. For the entire study group, we found a highly significant correlation (r = 0.86) between the serum IGF-I concentration and the ability of that serum to stimulate thymidine incorporation into the DNA of FRTL5 cells. The stimulatory effects of serum from both normal and acromegalic subjects were decreased or abolished by the addition of a monoclonal antibody against IGF-I. In hypophysectomized rats, GH increases the thyroid to body weight ratio and enhances the effect of TSH to promote thyroid growth. Further, an inordinate frequency of nontoxic goiter in patients with acromegaly has been reported. Taken together with these observations, our findings suggest that the effect of IGF-I to promote thyroid cell growth in vitro has a counterpart in the living animal or patient.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0021-972X
pubmed:author
pubmed:issnType
Print
pubmed:volume
66
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1227-32
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Supranormal stimulation of deoxyribonucleic acid synthesis in FRTL5 cells by serum from patients with untreated acromegaly.
pubmed:affiliation
Charles A. Dana Research Institute, Harvard Thorndike Laboratory, Beth Israel Hospital, Boston, Massachusetts 02215.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.