Purchase this article with an account.
S.J. Giebel, A. Das, P.G. McGuire; Upregulation of Extracelluar Proteinases and Angiopoietin 2 during Blood-Retinal-Barrier Alteration in the Diabetic Rat Model . Invest. Ophthalmol. Vis. Sci. 2003;44(13):3903.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: To examine the expression of extracellular proteinases and growth factors during blood-retinal-barrier alteration in an animal model. Methods: Diabetes was induced in Sprague-Dawley rats by a single intraperitoneal injection of 60mg/kg of streptozotocin. After 3 months of sustained hyperglycemia, rats (n=5) were catheterized and injected with Evans blue to quantitate vascular permeability in the retina. Age-matched non-diabetic rats (n=5) on normal diet served as controls. RNA was extracted from the retinas and analyzed by RT-PCR for the levels of extracellular proteinases (MMP2, MMP9, MT1-MMP, uPA and uPAR) and growth factors (Angiopoietin 1 and 2). Results: The retinal vascular permeability in diabetic animals was increased by two-fold after 3 months of diabetes. Significant elevations in proteinase expression (MMP9, MT1-MMP, uPA and uPAR) was seen in the retinas of diabetic animals compared to controls. No increase in MMP2 was seen in the retinas of the diabetic animals. There was significantly increased expression of Angiopoietin 2 in the retinas of diabetic animals, whereas there was no change in the level of Angiopoietin 1. Conclusions: The increased permeability of the blood-retinal-barrier in early diabetes is associated with an increased expression of proteinases and Angiopoietin 2. The expression of these proteinases in diabetes may facilitate an increase in vascular permeability in the retina leading to macular edema.
This PDF is available to Subscribers Only