|
|
|
|
 |
|||
|
|||
Permeability of rat choriocapillaris to hemeproteins. Restriction of tracers by a fenestrated endothelium
RM Pino and E Essner
The choriocapillaris is the fenestrated capillary bed in the choroid of the eye and is the major blood supply to the retinal pigment epithelium (RPE) and photoreceptor cells. Bruch's membrane (BM) is a multilaminated basement membrane that separates the choriocapillaris from the RPE. In a previous study (Pino RM, Essner E; Cell Tissue Res 208:21, 1980) we found that the choriocapillary endothelium restricted the egress of ferritin from the choriocapillaris. In the present study, hemeproteins were used to further establish the permeability characteristics of this capillary bed. Horseradish peroxidase (Einstein- Strokes radius (ESR), 30 A) rapidly crossed the capillary endothelium (less than 5 min) after intravenous administration and after 5 minutes filled BM and the basal infoldings of the RPE. In contrast, hemoglobin (Hg) (ESR, 32 A) and lactoperoxidase (LP) (ESR, approximately 40 A) are markedly restricted at the level of endothelial diaphragmed fenestrae, channels, and intercellular junctions. Little vesicular transport of these proteins was observed. The reaction product of the two hemeprotein activities was not demonstrable in BM for up to 30 min after injection; relatively low levels were detected after 75 min. HG and LP appear to be further restricted by BM, since their reaction products were not demonstrable between the RPE basal infoldings at this time. Catalase (ESR, 52 A) activity was not detected in BM for up to 4 hr after injection. These results indicate that the rat choriocapillary endothelium, unlike the fenestrated endothelia lining other vascular beds, substantially restricts the passage of large tracer molecules.
Volume 29,
Issue 2,
pp. 281-290,
02/01/1981
Copyright © 1981 by The Histochemical Society
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
This article has been cited by other articles:
|
|
 |
|
  D. J. Moore and G. M. Clover The Effect of Age on the Macromolecular Permeability of Human Bruch's Membrane Invest. Ophthalmol. Vis. Sci., November 1, 2001; 42(12): 2970 - 2975. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. A. Curcio, C. L. Millican, T. Bailey, and H. S. Kruth Accumulation of Cholesterol with Age in Human Bruch's Membrane Invest. Ophthalmol. Vis. Sci., January 1, 2001; 42(1): 265 - 274. [Abstract] [Full Text]
|
|
|
|
|
|
B. E. Brito, L. M. O’Rourke, Y. Pan, J. Anglin, S. R. Planck, and J. T. Rosenbaum IL-1 and TNF Receptor-Deficient Mice Show Decreased Inflammation in an Immune Complex Model of Uveitis Invest. Ophthalmol. Vis. Sci., October 1, 1999; 40(11): 2583 - 2589. [Abstract] [Full Text] [PDF]
|
|
| Guidelines | Subscriptions | About | exPRESS - Current - Archive | Business Information | Contact |