抄録
Ultimobranchial calcitonins (CTs) are known to stimulate intracellular adenosine 3': 5'cyclic monophosphate (cAMP) levels in mammalian cells. We examined the ability of cAMP production in 15 animal and 22 human cell lines treated with eel CT (ECT). Among cell lines accumulating cAMP in response to ECT, a porcine kidney cell line LLC-PKK1, showed the highest responsiveness. ECT at the concentrations of 10-11 M and higher inhibited the growth of LLC-PK1, monitored by three procedures of the cell number determination, the crystal violetstaining, and DNA synthesis. The extents of growth inhibition by CTs of ultimobranchial origin such as eel and salmon determined by the cell counts and the dye-staining method were essentially same. However, the quite weak activities of CTs of other than ultimobranchial origin, such as pig and human were detected by the dye-staining method compared to the cell counts. These results indicate that the dye-staining method monitoring the growth of LLC-PK1, is useful for estimation of ultimobranchial CT activity in vitro.
