Intravitreal administration of endothelin type A receptor or endothelin type B receptor antagonists attenuates hypertensive and diabetic retinopathy in rats

Abstract

Hypertension is an independent risk factor for diabetic retinopathy, yet anti-hypertensive medications such as blockade of angiotensin II do not completely protect against vision-threatening vascular disease. We hypothesized that the potent vasoactive factor, endothelin (ET), is up-regulated in diabetic retinopathy and antagonism of the ET type A receptor (ETRA) or ET type B receptor (ETRB) ameliorates retinal vascular leakage independently of any blood pressure lowering effects. Spontaneously hypertensive rats (SHR) and their normotensive and genetic controls, Wistar Kyoto rats, were randomized to become diabetic or non-diabetic and studied for 8 weeks. Rats were further randomized to recei..