Endothelial cell degeneration in the choriocapillaris

Network of the blood vessels formed by intussusception as well as sprouting. I noticed the deformed or degenerated endothelial cell that possibly shows the the intussusception to form the vascular network. Upper image is a choriocapillaris observed from the inner (retinal) side. Network of the choriocapillaris is indicated by arrows. Middle and lower images are in the rectangular area of the upper image. Bizarre and spider like endothelial cells were touched at the endothelial tubes of choriocapillaris (arrow in middle image). This images indicate that intussusception plays a role in network formation in choriocapillaris.

Pericyte process and fenestrated endothelial cells of choriocapillaris

Pericyte processes and endothelial cells at outer (scleral) side of choriocapillaris. (P) is a pericyte process and (F) is a fenestrated endothelial cells. Lower image is a higher magnification view. Fenestration sparsely distributed around the pericyte process. Endothelial cells without pericytes have rich fenestration. Pericytes seem to restrict fenestration by VEGF. Indeed, endothelial cells have fenestration at inner (retinal) side of choriocapillaris, which is influenced by VEGF secretion from retinal pigmented epithelial cells (RPE).

Pericyte of choriocapillaris at scleral side

This is a outer (scleral) side of the choriocapillaris that shows the pericyte associating the endothelial cells. The pericyte has long and slender processes indicated with white bars in the right high magnification image. The processes are branching. The pericyte observed here is similar to that of capillary in the ordinary vessels.

Electron microscopic images of scleral side of choriocapillaris

Lateral (scleral) side of choriocapillaris. This is a high magnification view of the image in previous post. The blood vessels are associated with pericytes indicated with arrows in the upper view. In this vessel, endothelial cells are fenestrated as well as those of retinal side (middle and lower views). Endothelial junction is seen in the upper side of the lower view.

3D-view of retina, bruch membrane and choriocapillaris

These are images of retina, Bruch's membrane and choroid including choriocapillaris. Choriocapillaris is broken but visible from lateral or scleral side. Choriocapillaris is fenestrated at the medial (retinal) side without pericyte coverage, but covered with pericytes at the lateral side. Next, I will show the details of choriocapillaris at lateral (scleral side).