Examination of the new importance of retinal vascular endothelial cells in retinal circulation using thrombin

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K17572
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Ophthalmology; General physiology
• Research Institution: Asahikawa Medical College
• Principal Investigator: Takahashi Kengo 旭川医科大学, 大学病院, 助教 (40646064)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 血液網膜関門 / トロンビン / プロテアーゼ活性型受容体 / PAR / 網膜静脈分枝閉塞症 / BRVO

Outline of Final Research Achievements

It was found that thrombin causes vasoconstriction when administered from the outside of the retinal vessel, but not when administered from the inside of the retinal vessel. This is supported by the previous report that the blood-retinal barrier does not allow passage of substances with a molecular weight above 1 kDa because thrombin has a large molecular weight of 33.6 kDa. As a result, it was considered that intravascular administration failed to act on smooth muscle and vasoconstriction could not occur. From these results, blood flow data of branch retinal vein occlusion (BRVO), which may leak from retinal vessels and act from outside the retinal vessels, is collected rather than the originally planned diabetic retinopathy. It was suggested that the blood flow was related to the change in retinal vein diameter, and the change in the diameter was related to the maximum best-corrected visual acuity.

Free Research Field

眼科

Academic Significance and Societal Importance of the Research Achievements

トロンビンは血液網膜関門を通過できず、血管内からは平滑筋に作用できないが、血液が血管より漏れ、血管外から作用しうる網膜静脈分枝閉塞症(BRVO)のような疾患に移おいては、網膜血管を収縮させ血流を悪くする可能性があるが、BRVOの血流データを収集したところ、網膜静脈血流は低下しており、その低下には血管径が細くなっていることが関与していることが分かったが、一方で、網膜静脈の血管径が小さい方が最高矯正視力が良いことわかった。このことから、BRVOのより良い治療を行うためには網膜静脈径の変化に伴う、網膜静脈組織の構造変化へアプローチすることが重要であることが示唆される。