Lee I, Yamagishi N, Oboshi K, Yamada H
Department of Clinical Veterinary Science, School of Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, Inada, Obihiro, Hokkaido 080-8555, Japan.
Vet J. 2003 Sep;166(2):194-7. doi: 10.1016/s1090-0233(03)00026-1.
This study was performed to clarify the antagonistic actions of intravenous or epidural atipamezole on the sedative and analgesic effects of xylazine administered between the epidural fat and dura mater through the first interlumbar space in cattle. Cattle received 5 mL of a solution containing 0.05 mg x kg(-1) xylazine in 0.9% saline. Thirty minutes later, 5 mL of 0.9% saline was administered through the same needle (treatment 1) (XSE). In treatments 2 (XAE) and 3 (XAV), 5 mL of a solution containing 0.025 mg x kg(-1) atipamezole in 0.9% saline was administered epidurally or intravenously, respectively. Sedation and analgesia were similar in all three treatment groups and could be reversed by atipamezole given by either route. In the XAV treatment, the flank area relapsed into analgesia 25+/-5.8 min following reversal of the analgesic effect, and was maintained for 112.5+/-63.8 min. The present study confirmed that the sedative and analgesic effects of xylazine are completely reversed by atipamezole and can be influenced by the epidural fat in cattle. Furthermore, it seems probable that analgesia following epidural administration of xylazine is mediated by alpha(2)-adrenergic receptors, not by a local anaesthetic effect.
本研究旨在阐明静脉注射或硬膜外注射阿替美唑对通过牛第一腰椎间隙在硬膜外脂肪和硬脑膜之间给予的赛拉嗪的镇静和镇痛作用的拮抗作用。牛接受了5 mL含0.05 mg/kg赛拉嗪的0.9%盐水溶液。30分钟后，通过同一针头给予5 mL 0.9%盐水（处理1）（XSE）。在处理2（XAE）和处理3（XAV）中，分别通过硬膜外或静脉注射给予5 mL含0.025 mg/kg阿替美唑的0.9%盐水溶液。三个处理组的镇静和镇痛效果相似，且任一途径给予的阿替美唑均可逆转这些效果。在XAV处理中，镇痛效果逆转后25±5.8分钟，胁腹区域再次出现镇痛，并持续112.5±63.8分钟。本研究证实，阿替美唑可完全逆转赛拉嗪的镇静和镇痛作用，且在牛中其作用可受硬膜外脂肪影响。此外，硬膜外给予赛拉嗪后的镇痛作用似乎是由α2-肾上腺素能受体介导的，而非局部麻醉作用。
