Author/Editor		Gaberšček, S; Štiblar-Martinčič, D; Kališnik, M
Title		The influence of calcium on thyroid follicular cells FRTL-5 in vitro
Type		članek
Source		Folia Biol (Praha)
Vol. and No.		Letnik 44
Publication year		1998
Volume		str. 49-52
Language		eng
Abstract		The present work is based on the results of in vivo experiments on rats, which had shown that hypercalcemia had led to morphological and biochemical hyperfunction of thyroid follicular cells. The regulation of the activity of follicular cells hosuld directly, or indirectly via paracrine action of serotonin secreted from parafollicular cells, depend on the presence of calcium ions. The effect of calcium was studied on a cell line of rat follicular cells FRTL-5 (Fischer Rat Thyroid cells in Low serum) using three methods: measuring the quantity of produced cAMP (evelic adensosine 3',5'-menophosphate), measuring (3H)thymidine incorporation into cell DNA and transmission electron microscopy. Results show that calcium has no effect on cAMP production. Calcium at 1.3 mM, 3mM, 10 mM, 20 mM and 30 mM concentrations increases (3H)thymidine incorporation into cell DNA when compared with controls without calcium. Calcium at the concentration of 30 mM has no effect on FRTL-5 cell morphology, TSH (thyrotropin) stimulates follicular cells; at higher extracellular concentrations (3 mM, 10 mM, 20 mM, 30 mM), calcium diminishes its effect, presumably by activation of a cAMP phosphodiesterase which disintegrates cAMP and/or by inhibition of adenyl cyclase.
Descriptors		THYROID GLAND CALCIUM THYROTROPIN CYCLIC AMP THYMIDINE RATS DNA CELL LINE MICROSCOPY, ELECTRON, SCANNING TRANSMISSION