Iida H, Watanabe Y, Dohi S, Ishiyama T
Department of Anesthesiology and Critical Care Medicine, Gifu University School of Medicine, Japan.
Anesthesiology. 1997 Jul;87(1):75-81. doi: 10.1097/00000542-199707000-00011.
Ropivacaine produces a vasoconstriction of cutaneous vessels in contrast to vasodilation produced by bupivacaine. To evaluate direct spinal microvascular actions of these local anesthetics, the authors investigated the concentration-related effects of ropivacaine and bupivacaine on spinal pial vascular diameters using the spinal window technique.
Anesthetized dogs (n = 14) divided into two groups (ropivacaine, n = 7; bupivacaine, n = 7) were prepared for measurement of spinal pial vessel diameters by intravital microscopy in a spinal window preparation. The authors administered six concentrations of each drug (10(-8)-10(-3) M) under the window and directly measured the spinal pial arteriolar and venular diameters at sequential times. Physiologic data including mean arterial blood pressure (MAP) and heart rate (HR) were determined before and after topical application of each concentration of the drugs. In additional experiments (n = 18), the action of topical ropivacaine and bupivacaine solution on spinal vessels was evaluated in the presence of yohimbine, prazosin, and propranolol.
Ropivacaine significantly constricted whereas bupivacaine dilated pial arterioles and venules, both in a concentration-dependent manner. Microvascular alteration was not blocked with any of the adrenoceptor antagonists tested (yohimbine, prazosin, propranolol), each of which per se did not affect pial vessel diameters. Topical application of ropivacaine or bupivacaine did not induce any change in MAP or HR.
The present results indicate that ropivacaine constricts and bupivacaine dilates the pial vessels of the spinal cord in a concentration-dependent fashion, and the mechanisms involved in such actions do not seem to be mediated via alpha- or beta-adrenoceptor of spinal vasculature.
与布比卡因引起的血管舒张相反，罗哌卡因可导致皮肤血管收缩。为评估这些局部麻醉药对脊髓微血管的直接作用，作者采用脊髓视窗技术研究了罗哌卡因和布比卡因对脊髓软膜血管直径的浓度相关效应。
将14只麻醉犬分为两组（罗哌卡因组，n = 7；布比卡因组，n = 7），通过脊髓视窗制备的活体显微镜检查来测量脊髓软膜血管直径。作者在视窗下给予每种药物的六种浓度（10⁻⁸ - 10⁻³ M），并在连续时间点直接测量脊髓软膜小动脉和小静脉的直径。在局部应用每种浓度的药物之前和之后测定包括平均动脉血压（MAP）和心率（HR）在内的生理数据。在另外的实验（n = 18）中，在育亨宾、哌唑嗪和普萘洛尔存在的情况下评估局部应用罗哌卡因和布比卡因溶液对脊髓血管的作用。
罗哌卡因显著收缩而布比卡因扩张软膜小动脉和小静脉，两者均呈浓度依赖性。所测试的任何一种肾上腺素能受体拮抗剂（育亨宾、哌唑嗪、普萘洛尔）均未阻断微血管改变, 且每种拮抗剂本身均不影响软膜血管直径。局部应用罗哌卡因或布比卡因未引起MAP或HR的任何变化。
目前的结果表明，罗哌卡因以浓度依赖性方式收缩而布比卡因扩张脊髓软膜血管，并且这种作用所涉及的机制似乎不是通过脊髓血管系统的α或β肾上腺素能受体介导的。
