Figure 2: Endothelial cells in the renal artery stained with rhodamine-labeled phalloidin. The focal plane was adjusted to the surface (a) or basal (b) portion of the endothelial cells. The three-dimensional distribution of actin filaments reconstructed using 20 serial confocal optical sections from (a) to (b) is shown in (c) (stereo pair image). Thick stress fibers were observed in the basal portion of the cells oriented perpendicular to the direction of blood flow (b: see also stereo pair image). In contrast, both parallel and perpendicular stress fibers oriented along the direction of flow were seen in the apical portion of the cells (a: see also stereo pair image). To see stereo image (c), use special glasses or a light source split into the viewer’s eyes. The focal plane closer to the viewer in stereo image (c) is the apical surface of the renal endothelial cells. The arrow indicates the direction of blood flow. Bars in (b) and (c): 100 μm.