The study for analgesic effects of Magnesium

研究了镁对人术后疼痛、大鼠电流感知阈值（CPT）及组胺注射引起的大鼠脊髓c-fos蛋白表达的影响。研究了210例择期手术患者围手术期血清游离镁的变化。血清游离镁在手术和术后逐渐降低。腹部手术患者的下降幅度大于骨科和神经外科手术患者。对24例择期腹式子宫切除术妇女进行了硫酸镁给药对术后镇痛需求的影响。给镁组术后吗啡用量明显少于对照组。雄性Wistar大鼠分为6组：Gr 1（生理盐水）、Gr 2a（镁2mmol/kg）、Gr 2b（镁4mmol/kg）、Gr 3（吗啡2mg/kg）、Gr 4a（吗啡2mg/kg +镁2mmol/kg）、Gr4b（吗啡2mg/kg +镁4mmol/kg）。虽然第3,4a和4b组5Hz时CPT升高，但组间无差异。另一项研究将雄性Wistar大鼠分为4个处理组：Gr C（生理盐水）、Gr M1（镁30mg/kg）、Gr M5（镁150mg/kg）、Gr M10（镁300mg/kg）。然后，每只大鼠后爪接受S.C.注射组胺。脊髓切片用抗c-fos抗体免疫染色；计数各特异层中fos样免疫反应细胞（FLI）的数量。在L3和L4水平的切片中，Gr M5和M10的FLI标记神经元数量少于Gr C和M1。这些发现表明，镁可能是术后疼痛管理的有益辅助剂，并对脊髓神经元有影响，其中一些直接接受有害输入。

The effects of Magnesium on the postoperative pain in human, current perception threshold (CPT) in rat, and expression of c-fos protein in the spinal cord in rat evoked by histamine injection were studied.The changes in perioperative serum ionized Magnesium were investigated in 210 patients underwent elective operations. Serum ionized Magnesium was gradually decreased during operation and postoperative period. The decrease was greater in the patients with abdominal surgery than in those with orthopedic and neurosurgical operations. In 24 women undergoing elective abdominal hysterectomy, the effects of Magnesium sulfate administration on the postoperative analgesic requirements were studied. The amount of postoperative morphine in the Magnesium administrated group was smaller than control group.Male Wistar rats were allocated to six treatment groups : Gr 1(saline), Gr 2a (Magnesium 2mmol/kg), Gr 2b (Magnesium 4mmol/kg), Gr 3(morphine 2mg/kg), Gr 4a (morphine 2mg/kg + Magnesium 2mmol/kg), Gr4b (morphine 2mg/kg +Magnesium 4mmol/kg). Although CPT at 5Hz in Gr 3, 4a, and 4b increased, there were no intergroup differences.In another study, male Wistar rats were allocated to 4 treatment groups : Gr C (saline), Gr M1 (Magnesium 30mg/kg), Gr M5 (Magnesium 150mg/kg), Gr M10 (Magnesium 300mg/kg). Each rat then received an S.C. injection of histamine into the hind paw. Sections of the lumber spinal cord were immunostained with anti c-fos antibody ; the numbers of fos-like immunoreactive cells (FLI) in every specific lamina were counted. In the sections of L3 and L4 level, the numbers of FLI labeled neurons for Gr M5 and M10 were less than Gr C and M1.These findings suggested that Magnesium could be an interest adjuvant for postoperative pain management and have effects on spinal neurons, some of which directly receive noxious inputs.