Dong Ya-Ru, Gustafson Claire E, Wang Jun, Cui Ji-Zhe, Yoshitomi Takeshi
Department of Ophthalmology, the Second Hospital of Jilin University, Changchun 130041, Jilin Province, China.
Department of Ophthalmology, Akita University School of Medicine, Akita 010-8543, Japan.
Int J Ophthalmol. 2019 Mar 18;12(3):363-368. doi: 10.18240/ijo.2019.03.02. eCollection 2019.
To investigate the alterations in both structure and contractile responsiveness of ocular ciliary artery (OCA) in spontaneously hypertensive rat (SHR).
In this experiment, 20-week-old male SHR and Wistar Kyoto rat (WKY) were studied. The heart rate (HR), the blood pressure (BP; the systolic BP and the diastolic BP) of rats with an electronic sphygmomanometer were measured. Vascular morphometry and isometric tension measurement were used to investigate the alterations in structure and contractility of OCA.
A general narrowing of OCAs was observed in SHR compared to the control WYK. In SHR, the media of OCAs were thicker, the luminal diameters were smaller, and the media-to-lumen ratios were higher when compared with WKY (<0.05). The contractions of OCAs evoked by norepinephrine were smaller in SHR compared to control (<0.05). Then, OCAs were pretreated with iberiotoxin, L-NAME, or indomethacin 30min before norepinephrine-induced contraction. Iberiotoxin (0.1 µmol/L) has not changed the norepinephrine-induced contractions in OCAs from both groups. However, L-NAME (100 µmol/L) increased the vasoconstrictions, the increased extents were similar in SHR and WKY (>0.05). Indomethacin (10 µmol/L) decreased the contractions induced by norepinephrine in OCAs from WKY (<0.05), but did not change those contractions in vessels from SHR (>0.05).
Our results demonstrate that the structure and function of OCAs are altered in hypertension. OCAs from SHR are remodeled with decreased lumen diameter and increased media-to-lumen ratio. Moreover, the contractile responsiveness of OCAs from SHR is diminished due to the disruption of vasoconstrictive effect of prostaglandins.
研究自发性高血压大鼠（SHR）眼睫状动脉（OCA）的结构和收缩反应性变化。
本实验研究20周龄雄性SHR和Wistar Kyoto大鼠（WKY）。用电子血压计测量大鼠的心率（HR）、血压（BP；收缩压和舒张压）。采用血管形态测量和等长张力测量来研究OCA的结构和收缩性变化。
与对照WKY相比，SHR的OCA普遍变窄。与WKY相比，SHR的OCA中膜更厚，管腔直径更小，中膜与管腔比值更高（<0.05）。与对照组相比，SHR中去甲肾上腺素诱发的OCA收缩较小（<0.05）。然后，在去甲肾上腺素诱发收缩前30分钟，用iberiotoxin、L-NAME或吲哚美辛预处理OCA。iberiotoxin（0.1 μmol/L）未改变两组OCA中去甲肾上腺素诱发的收缩。然而，L-NAME（100 μmol/L）增加了血管收缩，SHR和WKY中的增加程度相似（>0.05）。吲哚美辛（10 μmol/L）降低了WKY的OCA中去甲肾上腺素诱发的收缩（<0.05），但未改变SHR血管中的这些收缩（>0.05）。
我们的结果表明，高血压时OCA的结构和功能发生改变。SHR的OCA发生重塑，管腔直径减小，中膜与管腔比值增加。此外，由于前列腺素血管收缩作用的破坏，SHR的OCA收缩反应性降低。
