Application of shear stress or pressure onto GFSHR-17 granulosa cells under perforated patch-clamp induced depolarization of the cell membrane by about 10 mV. The shear stress/ pressure related depolarization could not be suppressed by substitution of the Na+ ions by NMDG or choline in the extracellular solution, indicating that shear stress/ pressure stimulated opening of channels permeable to large molecules such as the fluorescent dye Lucifer Yellow. Gap junction hemichannels composed of connexins or pannexins are known to be such channels, which are permeable to large molecules. Using fluorescence microscope, it could be shown that shear stress/ pressure stimulated uptake of Lucifer Yellow. These results demonstrate that gap junction hemichannels of GFSHR-17 granulosa cells can be opened by a physiological relevant stimulation and in presence of extracellular physiological Ca2+ concentration.