Mpanduji D G., Bittegeko S B.P., Batamuzi E K., Mgasa M N., Shami C L.
Department of Veterinary Surgery and Theriogenology, Sokoine University of Agriculture, P.O. Box 3020, Morogoro, Tanzania
Small Rumin Res. 2001 May;40(2):117-122. doi: 10.1016/s0921-4488(00)00216-9.
The present study was carried out in order to compare the reversing effects of alpha(2)-adrenergic receptor antagonists, atipamezole and tolazoline on analgesia, cardiopulmonary depression and rectal temperature changes induced by epidural administration of medetomidine in goats. Eight clinically healthy, small East African goats of both sexes weighing between 12 and 17kg (mean 14.4+/-1.8kg) were used in this study. The animals were randomly divided into two groups of four animals. The first group was given 20µg/kg medetomidine followed by intravenous (IV) administration of 80µg/kg atipamezole, 30min after the initial injection. The second group was given same treatment for medetomidine as group one but followed by IV administration of 2.2mg/kg tolazoline, 30min after the initial injection. In both treatment groups, medetomidine was administered epidurally through the lumbosacral interspace. Analgesia of the flank and perineum was evaluated at every 10min intervals up to 60min. The cardiopulmonary and rectal temperature values were monitored and recorded at every 5min interval up to 60min. In both groups, lumbosacral epidural injection of medetomidine induced generalised analgesia, variable cardiopulmonary depression effects and non-significant changes on rectal temperature. These changes developed as early as 5min and continued until alpha(2)/alpha(1) antagonists were administered. Intravenous administration of alpha-adrenergic receptor antagonists; atipamezole and tolazoline reversed analgesia, cardiopulmonary and rectal temperature changes induced by lumbosacral epidural injection of medetomidine in goats. However, atipamezole appeared to be superior (P<0.05) to tolazoline. From this study, it was concluded that IV administration of 80µg/kg atipamezole was better than 2.2mg/kg tolazoline in reversing analgesia and cardiopulmonary depression effects induced by lumbosacral epidural injection of medetomidine in goats. This indicates the superiority of atipamezole to tolazoline as an antidote for medetomidine induced effects in goats.
本研究旨在比较α₂-肾上腺素能受体拮抗剂阿替美唑和妥拉唑啉对山羊硬膜外注射美托咪定所致镇痛、心肺抑制及直肠温度变化的逆转作用。本研究选用8只临床健康、体重在12至17千克之间（平均14.4±1.8千克）的东非小山羊，雌雄不限。将动物随机分为两组，每组4只。第一组先给予20μg/kg美托咪定，初始注射30分钟后静脉注射80μg/kg阿替美唑。第二组给予与第一组相同的美托咪定处理，但初始注射30分钟后静脉注射2.2mg/kg妥拉唑啉。在两个治疗组中，美托咪定均通过腰骶间隙硬膜外给药。每隔10分钟评估一次胁腹和会阴的镇痛情况，直至60分钟。每隔5分钟监测并记录心肺和直肠温度值，直至60分钟。在两组中，腰骶部硬膜外注射美托咪定均引起全身性镇痛、不同程度的心肺抑制作用以及直肠温度无显著变化。这些变化早在5分钟时就出现，并持续到给予α₂/α₁拮抗剂。静脉注射α-肾上腺素能受体拮抗剂阿替美唑和妥拉唑啉可逆转山羊腰骶部硬膜外注射美托咪定所致的镇痛、心肺及直肠温度变化。然而，阿替美唑似乎优于妥拉唑啉（P<0.05）。从本研究得出结论，静脉注射80μg/kg阿替美唑在逆转山羊腰骶部硬膜外注射美托咪定所致的镇痛和心肺抑制作用方面优于2.2mg/kg妥拉唑啉。这表明阿替美唑作为山羊美托咪定诱导效应的解毒剂优于妥拉唑啉。
