Figure 3.

Pericyte loss in retinal capillaries from transgenic mice overexpressing IGF-1. (A) Confocal analysis of retinal capillaries in flat-mounted retinas immunohistochemically marked with anti-collagen IV (green). Nuclei were counterstained with propidium iodide (red). Acellular capillaries, lacking pericytes and endothelial cells, were observed (arrowheads) in transgenic retina. The images are single confocal sections. (B) Retinal digest preparations were obtained as indicated in Methods. A representative area is shown (left panel). Endothelial cell nuclei are placed within the vessel wall, while pericyte nuclei are placed more laterally on the vessel wall (right panel). (C) The number of pericytes (left) and endothelial cells (right) per square millimeter of capillary area were determined as indicated in Methods. Results are mean ± SEM of five mice in each group. **P < 0.01. E, endothelial cell; P, pericyte. Scale bars: 35 μm (A), 43 μm (B, left panel), and 11 μm (B, right panel).