cGMP-regulated store-operated calcium entry in human hepatoma cells

This study aimed to investigate cGMP-regulated store-operated Ca(2+)entry in human 7721 hepatoma cells. Ca(2+)](i)was measured using Fura2/AM. After incubation of the cells with 4 microm thapsigargin, Ca(2+)entry was evoked by application of 1 mMm Ca(2+)to extracellular solution and was blocked by 3 m m Ni(2+), indicating the presence of store-operated Ca(2+)entry in human 7721 hepatoma cell line. Application of 8-Br-cGMP reduced the Ca(2+)](i)in hepatoma 7721 cells by 80%. These data demonstrated for the first time that store-operated Ca(2+)entry pathway is present in human hepatoma cells, which is regulated by cGMP.