Effect of intravitreal Rho kinase inhibitor ripasudil (K-115) on feline retinal microcirculation. (October 2015)

• Record Type: Journal Article
• Authors: Nakabayashi, Seigo; Kawai, Motofumi; Yoshioka, Takafumi; Song, Yong-Seok; Tani, Tomofumi; Yoshida, Akitoshi; Nagaoka, Taiji
• Is Part Of: Experimental eye research. Volume 139(2015:Oct.)
• Page Start: 132
• Page End: 135
• Publication Date: 2015-10
• Subjects: Rho kinase inhibitor -- K-115 -- Laser Doppler velocimetry -- Retinal blood flow -- Ripasudil -- Microcirculation; BP blood pressure -- D diameter -- ET-1 endothelin-1 -- IOP intraocular pressure -- LDV laser Doppler velocimetry -- MABP mean arterial BP -- OPP ocular perfusion pressure -- PBS phosphate-buffered saline -- RBF retinal blood flow -- ROCK Rho-associated coiled-coil-forming protein kinase -- V velocity; Ophthalmology -- Periodicals; Eye -- Periodicals; Œil -- Périodiques; Ophthalmology; Periodicals; Electronic journals; 612.8405
• DOI: 10.1016/j.exer.2015.07.008
• Languages: English
• ISSNs: 0014-4835

Abstract

Abstract: Ripasudil (K-115) is a novel Rho kinase inhibitor with a potent intraocular pressure-lowering effect. However, it is unclear whether ripasudil affects the retinal blood flow (RBF). We investigated the effect of ripasudil on feline retinal microcirculation. Ripasudil (5 μM, 50 μM or 5 mM; n = 5 each concentration) or vehicle (PBS; n = 5) was injected intravitreally. The vessel diameter (D) and blood velocity (V) were measured by laser Doppler velocimetry simultaneously in the first-order retinal arterioles and the RBF was calculated. The measurements started 5 min before the injection and were performed every 10 min for 120 min. After the intravitreal injection, the retinal circulatory parameters did not change significantly in PBS or 5 μM of ripasudil. The blood V and RBF increased significantly compared to baseline, whereas the vessel D did not change significantly in 50 μM and 5 mM of ripasudil. The V in 50 μM, and the V and RBF in 5 mM of ripasudil significantly increased compared to those in PBS. Intravitreal administration of ripasudil increased the blood V and RBF in cats, suggesting that ripasudil has the potential to improve the retinal blood flow. Highlights: Ripasudil (K-115) is a novel Rho kinase inhibitor. We administered ripasudil to cats, and measured blood flow in retinal artery. Intravitreal administration of ripasudil increased retinal blood velocity and flow.