title: Effect of intravitreal Rho kinase inhibitor ripasudil (K-115) on feline retinal microcirculation.
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.
authors.affiliation: Department of Ophthalmology, Asahikawa Medical University, Asahikawa, Japan. Electronic address: nby@asahikawa-med.ac.jp.
authors.forename: Seigo
authors.initials: S
authors.lastname: Nakabayashi
authors.affiliation: Department of Ophthalmology, Asahikawa Medical University, Asahikawa, Japan. Electronic address: m-kawai@asahikawa-med.ac.jp.
authors.forename: Motofumi
authors.initials: M
authors.lastname: Kawai
authors.affiliation: Department of Ophthalmology, Asahikawa Medical University, Asahikawa, Japan. Electronic address: takafumiyoshioka@hotmail.com.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Yoshioka
authors.affiliation: Department of Ophthalmology, Asahikawa Medical University, Asahikawa, Japan. Electronic address: ysong@asahikawa-med.ac.jp.
authors.forename: Yong-Seok
authors.initials: YS
authors.lastname: Song
authors.affiliation: Department of Ophthalmology, Asahikawa Medical University, Asahikawa, Japan. Electronic address: asa555@asahikawa-med.ac.jp.
authors.forename: Tomofumi
authors.initials: T
authors.lastname: Tani
authors.affiliation: Department of Ophthalmology, Asahikawa Medical University, Asahikawa, Japan. Electronic address: ayoshida@asahikawa-med.ac.jp.
authors.forename: Akitoshi
authors.initials: A
authors.lastname: Yoshida
authors.affiliation: Department of Ophthalmology, Asahikawa Medical University, Asahikawa, Japan. Electronic address: nagaoka@asahikawa-med.ac.jp.
authors.forename: Taiji
authors.initials: T
authors.lastname: Nagaoka
mesh_terms: D000818:Animals; D002415:Cats; D004195:Disease Models, Animal; D005260:Female; D058449:Intravitreal Injections; D007546:Isoquinolines / Q000008:administration & dosage*; D017078:Laser-Doppler Flowmetry; D008297:Male; D008833:Microcirculation / Q000187:drug effects*; D012039:Regional Blood Flow / Q000187:drug effects*; D012164:Retinal Diseases / Q000188:drug therapy* / Q000503:physiopathology; D012171:Retinal Vessels / Q000187:drug effects* / Q000503:physiopathology; D013449:Sulfonamides / Q000008:administration & dosage*; D054460:rho-Associated Kinases / Q000037:antagonists & inhibitors*
chemical_list: D007546:Isoquinolines; C584679:K-115; D013449:Sulfonamides; D054460:rho-Associated Kinases
keywords: K-115; Laser Doppler velocimetry; Microcirculation; Retinal blood flow; Rho kinase inhibitor; Ripasudil