Gozariu M, Bustamante D, Le Bars D, Willer J C
Laboratory of Neurophysiology, Faculty of Medicine Pitié-Salpêtrière, Paris, France.
Eur J Pharmacol. 1996 Oct 10;313(1-2):51-62. doi: 10.1016/0014-2999(96)00455-4.
A C-fibre reflex elicited by electrical stimulation within the territory of the sural nerve, was recorded from the ipsilateral biceps femoris muscle in anaesthetized rats. The temporal evolution of the response was studied using a constant stimulus intensity (3 x threshold) and recruitment curves were built by varying stimulus intensity from 0 to 7 x threshold. The intravenous administration of 0.02-0.2 mg/kg clonidine resulted in a dose-dependent depression of the C-fibre reflex. The alpha 2-adrenoceptor antagonist idazoxan completely prevented this depressive effect of clonidine. The effects of clonidine on the C-fibre reflex elicited by a wide range of stimulus intensities were investigated using recruitment curves: following 0.16 mg/kg clonidine, a dramatic shift of the recruitment curve to the right was seen with both an increase in the threshold and a decrease in the slope. Clonidine also produced a dose-dependent increase in blood pressure, but this was not correlated with the depression of the nociceptive reflex.
在麻醉大鼠中，通过电刺激腓肠神经支配区域引发C纤维反射，并记录同侧股二头肌的反应。使用恒定刺激强度（3倍阈值）研究反应的时间演变，并通过将刺激强度从0变化到7倍阈值来构建募集曲线。静脉注射0.02-0.2mg/kg可乐定导致C纤维反射呈剂量依赖性抑制。α2-肾上腺素能拮抗剂咪唑克生完全阻止了可乐定的这种抑制作用。使用募集曲线研究了可乐定对广泛刺激强度引发的C纤维反射的影响：在给予0.16mg/kg可乐定后，募集曲线明显右移，阈值升高且斜率降低。可乐定还使血压呈剂量依赖性升高，但这与伤害性反射的抑制无关。
