Thyroid-stimulating hormone stimulates increases in inositol phosphates as well as cyclic AMP in the FRTL-5 rat thyroid cell line

摘要: Studies were conducted to determine whether thyroid-stimulating hormone (TSH; thyrotropin), a known increase cytosol concentrations of cyclic AMP, also stimulates the formation inositol phosphates in thyroid cells. TSH and noradrenaline both stimulated [3H]inositol phosphate concentration-dependent manner rat cell line, FRTL-5 cells, which had been prelabelled with [3H]inositol. The threshold concentration required stimulate was more than 20 munits/ml, is approx. 10(3)-fold greater that for AMP accumulation growth these We demonstrate membranes prepared from cells possess guanine nucleotide-activatable polyphosphoinositide phosphodiesterase, suggests activation inositide metabolism may be coupled receptors by G-protein, Gp. Our findings suggest two second-messenger systems exist mediate action thyroid.