Figure 3. Time course of phosphodiesterase translocation. Rod outer segment (ROS) isolated from dark-adapted rats were exposed to room light (approximately 500 Lux) for various lengths of time, followed by fixation and preparation for immunogold electron microscopy. Percentage of total phosphodiesterase (PDE) adjacent to the plasma membrane (within 25 nm) was measured and plotted (p≤0.002 for 0 versus 1 min).