Sumida T, Tagami M, Ide Y, Nagase M, Sekiyama H, Hanaoka K
Department of Anesthesiology, Faculty of Medicine, University of Tokyo, Japan.
Anesth Analg. 1995 Jan;80(1):58-63. doi: 10.1097/00000539-199501000-00010.
The effects of intravenously (i.v.) administered midazolam on noxiously evoked activity of spinal wide dynamic range (WDR) neurons were investigated in decerebrate, spinal-cord-transected cats. Extracellular, single-unit recordings were measured during stimulation by pinching the receptive field on the hind paw and the effect of midazolam at doses of 0.25, 0.5, 1, 2, and 4 mg/kg were measured. Two series of experiments were performed to characterize the analgesic effects of midazolam. In the first, dose-response experiments (n = 59) demonstrated a dose-dependent suppression of the noxiously evoked activity of spinal WDR neurons after midazolam administration. This effect of midazolam was maximal at a dose of 1 mg/kg i.v.. The second series of experiments (n = 14) demonstrated that a benzodiazepine antagonist, flumazenil (n = 8), promptly reversed the effect of midazolam, while an opioid antagonist, naloxone (n = 6), had no effect on the effect of midazolam. The present study demonstrates that i.v. administered midazolam suppresses noxiously evoked activity of spinal WDR neurons that is reversible by a benzodiazepine antagonist. This is consistent with an analgesic action of midazolam.
在去大脑、脊髓横断的猫中，研究了静脉注射咪达唑仑对脊髓广动力范围（WDR）神经元有害刺激诱发活动的影响。通过捏后爪的感受野进行刺激时，测量细胞外单单位记录，并测量0.25、0.5、1、2和4mg/kg剂量咪达唑仑的作用。进行了两个系列的实验来表征咪达唑仑的镇痛作用。在第一个实验中，剂量反应实验（n = 59）表明，静脉注射咪达唑仑后，脊髓WDR神经元有害刺激诱发活动受到剂量依赖性抑制。咪达唑仑的这种作用在静脉注射1mg/kg剂量时最大。第二个系列实验（n = 14）表明，苯二氮䓬拮抗剂氟马西尼（n = 8）能迅速逆转咪达唑仑的作用，而阿片类拮抗剂纳洛酮（n = 6）对咪达唑仑的作用没有影响。本研究表明，静脉注射咪达唑仑可抑制脊髓WDR神经元有害刺激诱发的活动，且这种作用可被苯二氮䓬拮抗剂逆转。这与咪达唑仑的镇痛作用一致。
