The ocular hypotensive effect of the ETB receptor selective agonist, sarafotoxin S6c, in rabbits.
The ocular hypotensive effect of the ETB receptor selective agonist, sarafotoxin S6c, in rabbits.
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DOI：
10.11501/3133631
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发表时间：
1995-04
影响因子：
4.4
通讯作者：
M. S. Haque;T. Taniguchi;K. Sugiyama;K. Okada;Y. Kitazawa
中科院分区：
文献类型：
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作者：
M. S. Haque;T. Taniguchi;K. Sugiyama;K. Okada;Y. Kitazawa
内皮素-1（ET-1）可影响兔眼内压（IOP），其作用可能是由受体ETA、ETB或两者共同介导的。Sarafotoxin S6 c（STX-S6 c）是ETB受体的选择性激动剂。作者试图用STX-S6 c阐明ETB受体在ET-1引起的兔眼内压变化中的作用，并确定不同剂量STX-S6 c与眼内压反应之间的关系。方法玻璃体内注射10（-4）~ 10（-7）M的STX-S6 c（20 μ l/眼）。每个人的对侧眼睛用作对照。使用经校准的气压计定期测量IOP。在玻璃体内注射STX-S6 c（10（-5）M）之前和之后，腹膜内给予吲哚美辛（50 mg kg-1）或媒介物（10 ml kg-1; 0.05 M磷酸盐缓冲液）两次，并以相同的方案测量IOP 24小时。结果STX-S6 c（10（-4）M和10（-5）M）组的眼压分别从注射后6 h和4 h开始下降至192 h和72 h，与基线相比差异有显著性（P < 0.05 ~ P < 0.01）。10（-6）M STX-S6 c溶液也导致从注射后24至72小时观察到的IOP显著降低（P < 0.05）。STX-S6 c的10（-7）M溶液不能影响IOP。眼压反应曲线下面积与STX-S6 c剂量显著相关（r = -0.856; P = 0.0001）。吲哚美辛治疗不能影响STX-S6 c（10（-5）M）引起的IOP降低。在接受较高剂量STX-S6 c的眼睛中观察到睫状体注射和虹膜血管的一些扩张。结论STX-S6 c具有剂量依赖性的降低兔眼内压作用，其作用机制可能是通过ETB受体介导的。
PURPOSE Endothelin-1 (ET-1) is known to affect intraocular pressure (IOP) in rabbits, and the IOP response is likely to be mediated by the receptors ETA, ETB, or both. Sarafotoxin S6c (STX-S6c) is a selective agonist to ETB receptors. The authors attempted to clarify the role of ETB receptors in changes in IOP induced by ET-1 in rabbits using STX-S6c and to determine the relationship between the IOP response and various doses of STX-S6c. METHODS Each concentration (10(-4) to 10(-7) M) of STX-S6c was injected intravitreally (20 microliters/eye) into one eye. The contralateral eye of each was used as a control. The IOP was measured periodically using a calibrated pneumatonometer. Indomethacin (50 mg kg-1) or vehicle (10 ml kg-1; 0.05 M phosphate buffer) was administered intraperitoneally twice, before and after intravitreal injection of STX-S6c (10(-5) M), and IOP was measured in the same protocol for 24 hours. RESULTS In the STX-S6c (10(-4) and 10(-5) M) group, the IOP reduction was significant compared with the baseline (P < 0.05 to P < 0.01), starting from 6 and 4 hours and continuing until 192 and 72 hours after injection, respectively. A solution of 10(-6) M STX-S6c also resulted in significant reduction of IOP observed from 24 to 72 hours after injection (P < 0.05). The 10(-7) M solution of STX-S6c failed to affect IOP. The area under the curve of IOP response exhibited a significant correlation with the doses of STX-S6c (r = -0.856; P = 0.0001) in the treated eyes. Treatment with indomethacin failed to affect the IOP reduction caused by STX-S6c (10(-5) M). Ciliary injection and some dilatation of the iridial vessels were observed in eyes that received higher doses of STX-S6c. CONCLUSION STX-S6c reduces the IOP in rabbits in a dose-dependent fashion, presumably mediated through the ETB receptors.