Intercellular junctions of hyperplastic retinal pigment epithelium

Korte, Gary E.; Hirsch, Dan Alan

doi:10.1007/bf01941533

Cited by 4 publications

(2 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Similar observations have been made as regards the per meability of hyperplastic RPE. in which the outer bloodretinal barrier can remain intact in spite of mitosis among RPE cells [10]. The breaking and reformation of junction al complexes during endothelial removal in atrophic CC or endothelial mitosis during CC regeneration may be so fast that too little tracer escapes to give reaction prod uct above background or control levels.…”

Section: Discussionmentioning

confidence: 99%

Permeability of Regenerating and Atrophic Choriocapillaris in the Rabbit

Korte¹,

Cushin²,

Delman³

1989

Cells Tissues Organs

View full text Add to dashboard Cite

When rabbits receive intravenous injections of sodium iodate, large expanses of the retinal pigment epithelium are destroyed. The adjacent capillary bed, the choriocapillaris, atrophies in response to the loss of the pigment epithelium and then regenerates. This provides a model of the permeability of regenerating and atrophic choriocapillaris, which we studied using intravenously injected horseradish peroxidase and catalase. Regenerating capillaries were permeable to peroxidase but not catalase. The permeability to peroxidase was probably due to endothelial fenestrations, since catalase (which is larger than peroxidase and does not penetrate endothelial fenestrae) was retarded at interendothelial junctional complexes, indicating that they were intact. Atrophic choriocapillaries were impermeable to catalase but displayed a heterogeneous permeability to peroxidase.This was correlated with the presence or absence of fenestrae; capillary profiles lacking fenestrae retained peroxidase in their lumina, whereas if fenestrae were present the tracer penetrated into the pericapillary space. The observations indicate that: (1) the permeability of the regenerating choriocapillaris is qualitatively similar to the mature choriocapillaris, and (2) the atrophic choriocapillaris undergoes changes in permeability that are primarily correlated with the loss of endothelial fenestrae. The observations provide a functional correlate – change in permeability – for structural changes in choriocapillaris endothelium (thickening, loss of fenestrae) in response to destruction of the retinal pigment epithelium, which has been postulated to exert a trophic effect on these capillaries.

show abstract

Section: Discussionmentioning

confidence: 99%

Permeability of Regenerating and Atrophic Choriocapillaris in the Rabbit

Korte¹,

Cushin²,

Delman³

1989

Cells Tissues Organs

View full text Add to dashboard Cite

show abstract

“…These complexes were formed among different types of RPE, indicating they are derived from the original RPE sheet, and none of them are from cells passing through or invading the epithelial sheet, e.g., macro phages [9], In small lesions, where regener ated RPE cells formed a continuous sheet of cells along Bruch's membrane, the HRP reac tion products stained Bruch's membrane and accumulated between the basal folds and in the intercelluar spaces, but stopped short of the apical junctional complexes. The forma tion of a barrier by regenerating hyperplastic RPE cells along Bruch's membrane has also been described following argon laser photo coagulation [8] as well as in other situations such as sodium iodate retinotoxicity [18]. In foci of SRN in the large lesions, HRP reaction products also filled the pericapillary spaces, but the RPE cells forming a confluent layer around the vessels appeared to serve as a bar rier to further diffusion of HRP.…”

Section: Discussionmentioning

confidence: 99%

Restoration of the Outer Blood-Retinal Barrier after Krypton Laser Photocoagulation

Pollack¹,

Korte

1993

Ophthalmic Res

View full text Add to dashboard Cite

The restoration of the outer blood-retinal barrier following krypton laser injury to the rat retina was studied at small and large laser lesions using intravenously injected sodium fluorescein, horseradish peroxidase, and catalase. The regenerated choriocapillaris and new blood vessels were permeable to fluorescein and peroxidase, but not to catalase. The regenerating retinal pigment epithelium gradually reformed a continuous sheet of cells covering all small laser sites and the periphery of large lesions. Zonulae occludens between the regenerated cells restored the outer retinal barrier and prevented diffusion of peroxidase into the retina. This occurred along Bruch’s membrane and the new blood vessels that were covered by the regenerated pigment epithelial cells, but not in the center of the large lesion that was not relined by regenerated cells.

show abstract

Repair of outer blood-retinal barrier after severe ocular blunt trauma in rabbits

Hui

Xiao

et al. 1993

Graefe's Arch Clin Exp Ophthalmol

View full text Add to dashboard Cite

Retinal contusion is a leading cause of visual loss in ocular blunt trauma. However, its pathogenesis remains controversial. We established a rabbit model of severe retinal contusion with energy of about 2.87 J. Typical retinal edema and sometimes subretinal hemorrhage reproducibly occurred at the posterior pole after injury. These subsided 1 week later with depigmentation in the lesion. Histopathological examination revealed severe damage of the outer layer of retina, for example, disruption of retinal pigment epithelium (RPE) and photoreceptors. Electroretinography showed a decrease in the b wave by 38-47% in amplitudes (P < 0.01) during the first 3 days and then returned, although not to normal level. To investigate the damage and repair of blood-retinal barrier (BRB), 5 ml 2% lanthanum solution (La) was injected via the common carotid artery 1-2 min before enucleation. La diffused in the interphotoreceptor space through the damaged junctions of RPE 1 h-3 days after injury. La also reached the nuclei level of photoreceptors up to 14 days after injury. Although a glial scar with scattered RPE cells attached to Bruch's membrane in the severely damage area, no La diffusion was found in the retina 4 weeks after trauma. These results showed incomplete repair of outer BRB after severe blunt trauma.

show abstract

Intercellular junctions of hyperplastic retinal pigment epithelium

Cited by 4 publications

References 5 publications

Permeability of Regenerating and Atrophic Choriocapillaris in the Rabbit

Permeability of Regenerating and Atrophic Choriocapillaris in the Rabbit

Restoration of the Outer Blood-Retinal Barrier after Krypton Laser Photocoagulation

Repair of outer blood-retinal barrier after severe ocular blunt trauma in rabbits

Contact Info

Product

Resources

About