Abstract
Purpose: :
To evaluate the changes in occludin after experimental vein thrombosis in rats. Occludin is an integral plasma-membrane protein located specifically at tight junctions.
Methods: :
The retinal veins of 32 pigmented rats were occluded by means of fluorescein augmented laser photocoagulation. The animals were sacrificed after 4, 24 and 48 hours, their eyes were enucleated and retinas were harvested. Retina whole mounts were prepared for indirect immunohistochemistry using an anti-occludin primary antibody and were examined under confocal microscope. The retinas of 6 normal animals were used as controls.
Results: :
The characterisitc reticular fluorescense of occludin was detected along vascular branches in a three-dimentional manner with the help of the confocal microscope. Alterations in occludin distribution could be detected along thrombosed veins, peripheraly to the site of thrombosis. These alterations included irregular linear fluorescence and increased spaces of absent fluorescence in major vein branches compared to controls. The alterations in the superficial and deep vascular plexuses were less prominent including a reduced fluorescence of occludin. No changes were detected at the arteriolar walls. All findings were more prominent at 24 hours and 48 hours.
Conclusions: :
Blood-retina barrier impairment is expressed with morphological alterations of occludine distribution 4, 24 and 48 hours after experimentally induced vein thrombosis
Keywords: vascular occlusion/vascular occlusive disease • microscopy: confocal/tunneling • immunohistochemistry