Vasodilator effects of fasudil, a Rho-kinase inhibitor, on retinal arterioles in stroke-prone spontaneously hypertensive rats

Purpose: The aim of this study was to examine the vasodilator effect of fasudil, a Rho-kinase inhibitor, on retinal arterioles in stroke-prone spontaneously hypertensive rats (SHRSPs) and in age-matched normotensive Wistar-Kyoto rats (WKYs). Methods: Rats (12-14 weeks-old) were anesthetized with thiobutabarbital (120 mg/kg, intraperitoneal). Fundus images were captured with a digital camera that was equipped with a special objective lens. The vasodilator responses of retinal arterioles were assessed by measuring changes in the diameters of the vessels. Results: The baseline diameter of the retinal arteriole was significantly smaller in SHRSPs than in WKYs. Fasudil (50-200 mu g/kg/min, intravenous) dose-dependently increased the diameter of the retinal arteriole and decreased the systemic blood pressure in both groups. The vasodilator effect of fasudil on the retinal arteriole in SHRSPs was greater than in WKYs. Conclusions: These results suggest that fasudil has beneficial effects on retinal vascular complications associated with chronic hypertension.