کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6196740 | 1602587 | 2015 | 12 صفحه PDF | دانلود رایگان |
- Capillary degeneration occurs following retinal ischemia-reperfusion.
- Pericyte loss occurs after the appearance of endothelial cell degeneration.
- Vascular basement membranes remain unchanged.
- Reduction in VEGF expression in neuronal cells precedes capillary degeneration.
- Neuronal cells may play an important role in maintaining retinal vasculature.
Recent studies have shown retinal blood vessel damage in experimental models of retinal degeneration. The present study aimed to provide a detailed description of the structural and functional changes in retinal vasculature induced by retinal ischemia-reperfusion (I/R) in rats. Retinal ischemia was induced for 60Â min by raising the intraocular pressure to 130Â mmHg. Morphological changes in vascular components (endothelial cells, pericytes, and basement membranes), the patency and perfusion of blood vessels, and expression of vascular endothelial growth factor (VEGF) were assessed in the retinas at 2, 7, and 14 days after I/R. Significant reductions in vascular densities were observed at 7 and 14 days after I/R. Pericyte loss occurred after the appearance of endothelial cell degeneration, whereas the vascular basement membranes remained unchanged. Some vessels showed no perfusion in damaged retina. A decrease in the immunoreactivity of VEGF in the region extending from the ganglion cell layer to the outer plexiform layer was evident 2Â days after I/R. In retinal I/R model, retinal ganglion cells are rapidly (<2 day) damaged following reperfusion, therefore, the current results suggest that neuronal cell damage precedes capillary degeneration, and neuronal cells may play an important role in maintaining vascular structure and function through the production and release of endothelial cell survival factors, including VEGF. Neuronal cell damage could be an additional cause of progression of ischemic retinal damage by reducing blood supply to the retinal neurons due to the destruction of the blood vessel network.
Journal: Experimental Eye Research - Volume 135, June 2015, Pages 134-145