Presence of epidermal growth factor receptors on human thyroid membranes.
The nature of epidermal growth factor (EGF) receptors in normal and pathological thyroid membranes was studied on a crude membrane fraction (10,000 X g pellet) of tissue homogenate. Optimal binding of 125I-EGF to human thyroid membranes was obtained at 25 degrees C with 1-h incubation at pH 7.4. The study revealed the presence of both high and low affinity receptors in normal and pathological thyroid membranes. The association constants of high affinity receptor (3.2 X 10(-9) mol/l) and of low affinity receptor (1.8 X 10(-8) mol/l) observed in normal thyroid membranes were similar to those of thyroid membranes from neoplastic as well as thyrotoxic thyroid tissues. [3H]thymidine incorporation into DNA of cultured human thyroid cells was stimulated by EGF in a dose-dependent manner. A half-maximal stimulation was found around 1 X 10(-10) mol/l. These results suggest that EGF may have a possible role in the regulation of thyroid growth and function in physiological and pathological situations.
D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D004247:DNA / Q000096:biosynthesis; D004815:Epidermal Growth Factor / Q000494:pharmacology; D066246:ErbB Receptors / Q000378:metabolism*; D008297:Male; D051379:Mice; D013961:Thyroid Gland / Q000378:metabolism*; D013964:Thyroid Neoplasms / Q000378:metabolism; D013971:Thyrotoxicosis / Q000378:metabolism
D004815:Epidermal Growth Factor; D004247:DNA; D066246:ErbB Receptors