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

This study aimed to investigate cGMP-regulated store-operated Ca2+ entry in human 7721 hepatoma cells. [Ca2+](i) was measured using Fura2/AM. After incubation of the cells with 4 mum thapsigargin, Ca2+ entry was evoked by application of 1 mm Ca2+ to extracellular solution and was blocked by 3 mm Ni2+, indicating the presence of store-operated Ca2+ entry in human 7721 hepatoma cell line. Application of 8-Br-cGMP reduced the [Ca2+](i) in hepatoma 7721 cells by 80%. These data demonstrated for the first time that store-operated Ca2+ entry pathway is present in human hepatoma cells, which is regulated by cGMP. (C) 2001 Academic Press.