Abstract
To investigate the mechanism of ATP release from the cells by mechanical stimulations, we have developed a real-time ATP imaging system under microscope. Bioluminescence emitted by the reaction of Luciferin-Luciferase and ATP is detected using a high quantam-yield image intensifier and a high performance cooled-CCD camera. The system enables the ATP imaging with 100 ms time-resolution under an upright microscope with x20 water immersion objective (NA0.95). The system also enables simultaneous imaging of Nomarski during ATP luminescence imaging. Using this system we observed [1] touch induced ATP release, [2] stretch induced ATP release, and [3] spontaneous ATP release in Ca2+-free solution (CFS), in cultured mammary epithelial cells. In [2], ATP is released intensely from a limited number of cells, and the number increases with increase of stretch length. With a similar manner, in [3], ATP is released, although the time course of the release is completely different. The ATP release by CFS is ten times slower than by stretch, suggesting a difference of ATP releasing mechanism between them. [Jpn J Physiol 55 Suppl:S80 (2005)]
