Abstract
Purpose :
Retinal ischemia is a major cause of blindness in the world. Researchers in the last couple of decades have focused on protecting the retina after ischemia by focusing on the retina itself. However, even today, few therapies are available. Within cerebral ischemia, vasculature has become a new focus for treatment approaches. After ischemia cerebral vasculature exhibits an increase in vasoconstrictive receptor expression which exacerbates cerebral damage after reperfusion. In the retina, few studies have evaluated the vascular effects following ischemia (Blixt et al 2016). This project evaluates the ophthalmic artery after the commonly known filamentous middle cerebral artery occlusion model which due to the immediate proximity of the ophthalmic artery to the MCA, also occludes the ophthalmic artery.
Methods :
The vascular properties of the ophthalmic artery were evaluated with wire myography while immunohistochemistry coupled with fluorescence microscopy was used to visualize endothelin-1 receptor expression in the artery in both ischemic and control arteries.
Results :
Results show an ETB mediated vasoconstriction in MCAO operated animals which does not occur on controls. Furthermore, ETB receptors are shown to be expressed in the smooth muscle cell layer after ischemia while controls express ETB receptors only in endothelial cell.
Conclusions :
This study shows an increase in ETB mediated vasoconstriction in the ophthalmic artery after 48 hours induced by 2 hours of ophthalmic artery occlusion. This increase can lead to further decreased blood flow to the retina after occlusion/reperfusion and might thus become a valid target for future therapies.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.