Cattet Marc R, Caulkett Nigel A, Lunn Nicholas J
Canadian Cooperative Wildlife Health Centre, Department of Veterinary Pathology, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, Saskatchewan, S7N 5B4, Canada.
J Wildl Dis. 2003 Jul;39(3):655-64. doi: 10.7589/0090-3558-39.3.655.
Immobilization features and physiologic effects of combinations of xylazine-zolazepam-tiletamine (XZT) and zolazepam-tiletamine (ZT or Telazol) were compared in nine captive and 17 free-ranging polar bears (Ursus maritimus) between 1998 and 2001. Although induction time was similar between drugs, induction dosage and volume were less with XZT. Induction of immobilization with XZT was predictable and smooth, muscle relaxation was good, and all bears remained completely immobilized and unresponsive to stimuli throughout a 1 hr handling period. The combination XZT was safely tolerated at two to three times the recommended dosage of 5 mg/kg (i.e., xylazine at 2 mg/kg + Telazol at 3 mg/kg). Bears immobilized with XZT had slower pulse rates, higher mean arterial pressures, and lower arterial oxygen tensions than bears immobilized with ZT. Rectal temperature increased slowly over time (approximately 0.5 C per hr) following immobilization with XZT. Based on response to a painful stimulus (compression of a claw bed), XZT was a more effective analgesic than ZT. Although the immobilization effects of XZT could not be reversed with the alpha 2-antagonist drug tolazoline, they were reversed with yohimbine or atipamezole. However, the time to complete reversal of effects (i.e., standing and ambulatory) was highly variable among bears.
1998年至2001年间，在9只圈养和17只自由放养的北极熊（Ursus maritimus）中比较了赛拉嗪 - 唑拉西泮 - 替来他明（XZT）和唑拉西泮 - 替来他明（ZT或Telazol）组合的麻醉特性和生理效应。尽管两种药物的诱导时间相似，但XZT的诱导剂量和体积较小。XZT诱导麻醉的过程可预测且平稳，肌肉松弛良好，所有北极熊在1小时的处理期内均保持完全麻醉且对刺激无反应。XZT组合在推荐剂量5mg/kg的两到三倍（即赛拉嗪2mg/kg + Telazol 3mg/kg）时能安全耐受。与用ZT麻醉的北极熊相比，用XZT麻醉的北极熊脉搏率较慢，平均动脉压较高，动脉血氧张力较低。用XZT麻醉后，直肠温度随时间缓慢升高（约每小时0.5℃）。基于对疼痛刺激（爪床压迫）的反应，XZT比ZT是更有效的镇痛药。尽管XZT的麻醉效果不能用α2拮抗剂托拉唑啉逆转，但可用育亨宾或阿替美唑逆转。然而，不同北极熊之间效应完全逆转（即站立和走动）的时间差异很大。
