Schaefer C F, Brackett D J, Biber B, Lerner M R, Holaday J W, Wilson M F, Fagraeus L
Department of Anesthesiology, University of Oklahoma Health Sciences Center, Oklahoma City 73190.
Regul Pept. 1989 Mar;24(3):269-82. doi: 10.1016/0167-0115(89)90223-1.
Thyrotropin-releasing hormone (TRH) possesses significant arousing and cardio-respiratory stimulant actions. The effects of a 2 mg/kg i.v. bolus dose of TRH on respiration and systemic hemodynamics were compared in conscious, freely-moving rats and during anesthesia with 4 different anesthetics. Fifty-four male Sprague-Dawley rats weighing 285 +/- 4 g (mean +/- S.E.M.) were divided into 5 groups: conscious, enflurane (2%), isoflurane (1.4%), pentobarbital (8 mg/kg/h i.v.), and ketamine (60 mg/kg/h i.v.). Anesthetized rats were intubated and breathed oxygen or anesthetic/oxygen spontaneously. Aortic blood pressure, heart rate, cardiac output, respiratory rate, arterial blood pH, blood gases, lactate and glucose were measured, and data were collected over a 20 min baseline period and for 130 min post-TRH. TRH increased respiratory rate in all groups; concomitant changes in arterial PCO2 indicated increased minute ventilation in the inhalation agent groups but not in the i.v. anesthetic groups or in the awake group. Significant respiratory depression in the enflurane group was rapidly reversed by TRH. The respiratory stimulant and arousing effects of TRH were smallest with ketamine anesthesia. The hemodynamic responses to TRH were consistent with a pattern of sympathoadrenalmedullary activation and were relatively uniform across groups despite anesthetic-induced alterations in baseline values. TRH or its analogues may prove useful as an analeptic in clinical anesthesia.
促甲状腺激素释放激素（TRH）具有显著的兴奋及心肺刺激作用。比较了2mg/kg静脉推注剂量的TRH对清醒、自由活动大鼠以及使用4种不同麻醉剂麻醉的大鼠的呼吸和全身血流动力学的影响。54只体重285±4g（均值±标准误）的雄性Sprague-Dawley大鼠被分为5组：清醒组、恩氟烷（2%）组、异氟烷（1.4%）组、戊巴比妥（静脉注射8mg/kg/h）组和氯胺酮（静脉注射60mg/kg/h）组。麻醉大鼠进行气管插管，自主呼吸氧气或麻醉剂/氧气混合气。测量主动脉血压、心率、心输出量、呼吸频率、动脉血pH值、血气、乳酸和葡萄糖，并在20分钟的基线期以及TRH给药后130分钟收集数据。TRH使所有组的呼吸频率增加；动脉血二氧化碳分压的相应变化表明吸入麻醉剂组的分钟通气量增加，但静脉麻醉剂组和清醒组未增加。恩氟烷组明显的呼吸抑制被TRH迅速逆转。氯胺酮麻醉时TRH的呼吸刺激和兴奋作用最小。TRH的血流动力学反应与交感肾上腺髓质激活模式一致，尽管麻醉导致基线值改变，但各组间相对一致。TRH或其类似物可能被证明在临床麻醉中作为苏醒药有用。
