Fig. 1.

Immunohistochemical demonstration of postcapillary venules (PCVs) using confocal laser scanning microscope.

Immunoreactivity for endothelial nitric oxide synthase (eNOS) reveals a microvascular network in a submucosal/mucosal preparation of rat stomach (A). Arrows indicate the direction of venular drainage pathway originating from the mucosal capillary network (cap) that connects to a submucosal PCV (pcv) and is finally collected into a larger venule (v). An extracted single plane image of the same area shows the submucosal PCV and connecting larger venule but not the mucosal capillary network (B). Immunohistochemistry for α-smooth muscle actin (α-SMA) reveals the stellate morphology of mural cells (pericytes or vascular smooth muscle cells) with a round cell body (arrows) in a PCV of rat submucosal specimen (C–E). Hoechst 33342 was used for nuclei staining. In a larger venule, vascular smooth muscle cells are circumferentially arranged (F). All micrographs are reproduced from (16) with permission.