Video 4.
S1P induces PP shedding in vitro. 10 µM S1P caused immediate PP shedding from their MK stems, whereas no PP shedding was observed in MKs treated with vehicle within 1 h. The arrow shows MK stems disappeared during PP shedding. The arrowheads indicate platelet-like particles separated from the MK stems. Time is in minutes. This video is shown at 25 frames/s. Bar, 20 µm.