Calcium sensing by human medullary thyroid carcinoma cells

FEBS Letters

Ridefelt, Peter¹  Liu, Yi-Jia²  Gylfe, Erik²  Rastad, Jonas¹  Åkerström, Göran¹ 

[1] Department of Surgery, University Hospital, S-751 85 Uppsala, Sweden;Department of Medical Cell Biology, University of Uppsala, Biomedicum, Box 571, S-751 23 Uppsala, Sweden

关键词: Calcium;    Calcitonin;    Thyroid neoplasm;    Signal transduction;    CT;    calcitonin;    [Ca2+]i;    cytoplasmic calcium concentration;    MTC;    medullary thyroid carcinoma;    BSA;    bovine serum albumin;    FBS;    foetal bovine serum;   

DOI  :  10.1016/0014-5793(94)80200-9

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Regulation of the cytoplasmic calcium concentration ([Ca²⁺]_i) was studied in fura-2-loaded C-cells from two human medullary thyroid carcinomas (MTC). K⁺ depolarization induced sustained rise of [Ca²⁺]_i reversed by verapamil. Elevation of external Ca²⁺ from 0.5 to 3.0 mM triggered regular oscillations or steady-state increases of [Ca²⁺]_i. In Ca²⁺-deficient medium Sr²⁺ caused steady-state increase or oscillations of the 340/380 nm fluorescence ratio. The Ca²⁺ and Sr²⁺ actions were partially reversible by verapamil. La³⁺ and Ce³⁺ elicited transient [Ca²⁺]_i peaks independent of external Ca+²⁺, but no oscillations. The results indicate that human MTC cells express a parathyroid-like Ca²⁺ sensor coupled to intracellular mobilization and influx of Ca²⁺. A voltage-dependent Ca²⁺ influx may be of importance for the oscillations of [Ca²⁺]_i.

【 授权许可】

Unknown