PKG II inhibits the release of Ca²⁺ from the endoplasmic reticulum (ER).

<p>Either Ad-PKG II-infected or Ad-LacZ-infected cells growing in a 96-well plate were serum-starved for 12 h, loaded with 5 µM of membrane permeable calcium indicator fluo-3/AM for 30 min at 37°C in DMEM. After loading with the fluo-3/AM, cells were washed with PBS solution and suspended in DMEM, and then incubated with 8-pCPT-cGMP (100 µΜ and 250 µΜ) for 30 min, and then stimulated with EGF (100 ng/ml) for 5 min. Fluorescence measurements were performed using an Olympus Fluoview-500 confocal system. The data shown are the means ± SD from 5 independent experiments, each performed in duplicate [*P<0.05, compared to LacZ group; ^&P<0.05, compared to LacZ+EGF group, LacZ+cGMP(250 µM)+EGF group and PKG II+EGF group].