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

我们以躯体交感反射为参数，研究了鞘内注射α - 2肾上腺素受体激动剂、克拉定和美托咪定的镇痛和心血管作用。对可乐定进行了静脉给药研究，并对相关参数进行了评价。（方法）电刺激股神经诱发猫腰交感神经节体交感反射电位（A、C反射电位）。α -2激动剂通过前臂鞘内植入PE-10导管或静脉滴注给药。鞘内给药可乐定(1)反射电位降低，证明可乐定有降压和心动过缓的作用。(2) C反射电位下降表明可乐定通过涉及脊髓的中枢机制起镇痛作用。(1)静脉注射可乐定与鞘内注射可乐定的结果相似。(2)高剂量clonidin引起的颞叶高血压被认为是由外周血管α 1或α 2受体的激活引起的。鞘内应用美托咪定也影响交感反射电位，并通过涉及脊髓的中枢机制起镇痛作用。

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.