Honda Masashi, Shimizu Ryutaro, Nishikawa Ryoma, Teraoka Shogo, Tsounapi Panagiota, Kimura Yusuke, Morizane Shuichi, Hikita Katsuya, Takenaka Atsushi
Tottori University Faculty of Medicine, Department of Urology, Yonago, Japan.
Cent European J Urol. 2021;74(2):185-189. doi: 10.5173/ceju.2021.0022. Epub 2021 Apr 9.
The aim of this study was to investigate the effects of intravenous ghrelin administration on the micturition reflex in rats.
Continuous cystometrograms were performed with female Sparague-Dawley rats under urethane anesthesia. Stable micturition cycles were established, and ghrelin was then administered intravenously to evaluate changes in bladder activity. In this experiment investigating the role of opioid systems, ghrelin was administered intravenously at the time of first observed bladder contraction after intravenous administration of naloxone methiodide, an opioid receptor antagonist.
Intravenous administration of ghrelin increased intercontraction interval that was dose-dependent. These inhibitory effects returned to pre-controls level within 80 minutes of administration. Similarly, intravenous administration of ghrelin increased threshold pressure in a dose-dependent fashion. These inhibitory effects of ghrelin were antagonized by intravenous naloxone methiodide administration.
These results show that ghrelin inhibits the micturition reflex through an opioid-dependent mechanism in rats under urethane anesthesia.
本研究旨在探讨静脉注射胃饥饿素对大鼠排尿反射的影响。
在乌拉坦麻醉下，对雌性斯帕rague-Dawley大鼠进行连续膀胱测压。建立稳定的排尿周期，然后静脉注射胃饥饿素以评估膀胱活动的变化。在本研究阿片系统作用的实验中，在静脉注射阿片受体拮抗剂甲硫碘化纳洛酮后首次观察到膀胱收缩时静脉注射胃饥饿素。
静脉注射胃饥饿素可增加收缩间期，且呈剂量依赖性。这些抑制作用在给药后80分钟内恢复到给药前水平。同样，静脉注射胃饥饿素以剂量依赖方式增加阈压力。胃饥饿素的这些抑制作用可被静脉注射甲硫碘化纳洛酮所拮抗。
这些结果表明，在乌拉坦麻醉的大鼠中，胃饥饿素通过阿片依赖机制抑制排尿反射。
