The effects of intrathecally administered alpha 2 agonists on somato-sympathetic reflex

我们研究了鞘内注射α 2肾上腺素受体激动剂可乐定和美托咪定的镇痛和心血管作用，以躯体交感神经反射为参数。关于可乐定，研究了静脉给药，并评价了相同的参数。（方法）电刺激猫的股神经，诱发腰交感神经节的躯体-交感神经反射电位（A和C反射电位）。α-2激动剂通过鞘内植入的PE-10导管或前臂的静脉管线给药。（结果）1.鞘内注射可乐定（1）A反射电位降低，证明可乐定有镇静和心动过缓作用。(2)C反射电位降低提示可乐定镇痛作用是通过脊髓中枢机制实现的.静脉注射可乐定（1）鞘内注射可乐定与鞘内注射可乐定的效果相似。(2)高剂量可乐定引起的颞叶高血压被认为是通过激活外周血管的α 1或α 2受体引起的.鞘内应用美托咪定也影响交感神经反射电位，并通过涉及脊髓的中枢机制发挥镇痛作用。

We studied the analgesic and cardiovasucular effect of intrathecally administered alpha 2 adrenoceptor agonists, clonidine and medetomidine, using somato-sympathetic reflex as a parameter. Concerning for clonidine, intravenous administration was studied and the same parameters were also evaluated.(Method)Somato-sympathetic reflex potentials (A and C reflex potentials) which were derived from lumbar sympathetic ganglion of cats by electrical stimulation of femoral nerve were induced. Alpha-2 agonists were administered from intrathecally implanted PE-10 catheter or intravenous line in the forearm.(Result)1. Intrathecal administeration of clonidine(1) Decreased A reflex potential proved that clonidine makes a role of hypotention and bradycardia.(2) Decreased C reflex potential indicates that clonidine act as an analgesic by central mechanism involving spinal cord.2. Intravenous administeration of clonidine(1) Intravenously applied clonidine also showed similar results as intrathecal clonidine.(2) Temporal hypertension observed in high dose of clonidin was thought to be elicited by activation of alpha 1 or alpha 2 receptors in peripheral vasculature.3. Intrathecally applied medetomidine also affects sympathetic reflex potentials and act as an analgesic by central mechanism involving spinal cord.