Differential effects of growth factors on [3H]thymidine incorporation and [125I]iodine uptake in FRTL-5 rat thyroid cells.
We studied the effect of several growth factors on DNA synthesis and function of FRTL-5 rat thyroid cells by simultaneous measurement of [3H]thymidine incorporation and [125I]iodide uptake. Endothelial cell growth factor, fibroblast growth factor, platelet-derived growth factor, and insulin-like growth factor I stimulated thymidine incorporation in a dose-dependent manner without the parallel increase of [125I]iodide uptake. These growth factors had an additive effect with thyroid-stimulating hormone (TSH) on thymidine incorporation, but they inhibited TSH-stimulated iodide uptake. Bombesin stimulated thymidine incorporation and inhibited TSH-stimulated iodide uptake; epidermal growth factor and gastrin-releasing peptide 10 had neither effect. None of the growth factors studied affected iodide uptake in the absence of TSH. Of the growth factors tested, endothelial cell growth factor, fibroblast growth factor, insulin-like growth factor bombesin, and platelet-derived growth factor all share similar differential effects on FRTL-5 cells: stimulation of DNA synthesis, potentiation of the effects of TSH on DNA synthesis, and attenuation of the effects of TSH on cell function. The data suggest that these growth factors may play important roles in regulation of thyroid function.
Pang
X P
XP
Endocrine Research Laboratory, Wadsworth Veterans Administration Medical Center, Los Angeles, California.
Hershman
J M
JM
D000818:Animals; D001839:Bombesin / Q000494:pharmacology; D002460:Cell Line; D004247:DNA / Q000096:biosynthesis*; D016228:Endothelial Growth Factors; D004815:Epidermal Growth Factor / Q000494:pharmacology; D005346:Fibroblast Growth Factors / Q000494:pharmacology; D019886:Gastrin-Releasing Peptide; D006133:Growth Substances / Q000494:pharmacology*; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology; D007455:Iodine / Q000378:metabolism*; D010455:Peptides / Q000494:pharmacology; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology; D051381:Rats; D011994:Recombinant Proteins / Q000494:pharmacology; D013936:Thymidine / Q000378:metabolism; D013961:Thyroid Gland / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology; D013972:Thyrotropin / Q000494:pharmacology
D016228:Endothelial Growth Factors; D006133:Growth Substances; D010455:Peptides; D010982:Platelet-Derived Growth Factor; D011994:Recombinant Proteins; D005346:Fibroblast Growth Factors; D004815:Epidermal Growth Factor; D007334:Insulin-Like Growth Factor I; D019886:Gastrin-Releasing Peptide; D013972:Thyrotropin; D004247:DNA; D007455:Iodine; D001839:Bombesin; D013936:Thymidine