Dorsal and ventral dopaminergic innervation of the spinal cord: Functional implications

Several studies have demonstrated that a descending dopaminergic pathway innervates the dorsal and the intermediate gray matter of the spinal cord and have suggested that this pathway is involved in pain modulation and in the control of autonomie functions. Other studies have also demonstrated the presence of dopamine (DA) and DA metabolites as well as of DA receptors in the ventral cord. There is also evidence for the implication of DA in the control of motor functions at the spinal level. The occurrence of a dopaminergic innervation in the ventral horn has been, however, disputed until recently. But recent work has demonstrated that the motoneural cell groups in the ventral horn (lamina IX) are a target for descending dopaminergic fibers. In addition, the possibility that DA is a mediator of primary afferent fibers has also been postulated. Finally, the occurrence of dopaminergic cell bodies has been suggested in the spinal cord. This indicates that DA is probably implicated in a complex manner in spinal functions. In the present paper the possible involvement of DA in sensory and in motor functions at spinal level will be discussed in view of neurochemical observations made in polyarthritic rats, in which pain-related behavior and reduction of locomotor activity associated with a marked decrease in mobility, are observed.     

大鼠不同脑区微量注射蝇蕈醇与氯苯氨丁酸镇痛作用比较

目的观察并比较GABAa受体激动剂蝇蕈醇及GABAb受体激动剂氯苯氨丁酸在大鼠不同脑区的镇痛作用。方法实验分侧脑室、室旁核和海马三组 ,每组又分成生理盐水对照组、蝇蕈醇组及氯苯氨丁酸组 ,分别经侧脑室、海马和室旁核”微量注射生理盐水或药物 ( 1× 1 0 - 3 mol·L- 1,1 μl) ,在大鼠甩尾测痛模型上”测定大鼠的痛阈。结果微量注射蝇蕈醇和氯苯氨丁酸在不同脑区均可不同程度地提高大鼠的痛阈 (与生理盐水对照组相比 ,P <0 .0 5或P <0 .0 1或P <0 .0 0 1 ) ,虽然蝇蕈醇与氯苯氨丁酸在侧脑室和室旁核的镇痛作用无显著性差异 (P >0 .0 5 ) ,但氯苯氨丁酸在海马的镇痛作用明显强于蝇蕈醇(P <0 .0 0 1 )。比较药物在不同脑区的镇痛作用发现 ,氯苯氨丁酸在海马和室旁核的镇痛作用无明显区别 ,但均强于侧脑室 ;而蝇蕈醇在室旁核最强 ,其次为海马、侧脑室。结论经侧脑室、海马或室旁核微量注射蝇蕈醇或氯苯氨丁酸均能降低大鼠对痛的感受性。氯苯氨丁酸在海马和室旁核可产生较强的镇痛作用 ,而蝇蕈醇在室旁核镇痛作用较明显 ,其次为海马     

Prenatal nicotine exposure increased duration of nicotine-induced analgesia in adult rats

The effect of prenatal exposure to nicotine on nicotine-induced analgesia was studied in rats. The analgesic effect of a single dose of nicotine (1 mg/kg SC) was measured by the tail-flick technique, and two subsequent studies were carried out. In the first study, 7-month-old male rats, born to dams chronically treated with nicotine during pregnancy (NIC), exhibited prolonged nicotine-induced analgesia compared to matched controls. The second study was designed to explore whether rats prenatally exposed to nicotine (NIC rats) are born with an increased sensitivity to nicotine and whether there is any sex difference. The analgesic effect of nicotine was tested on control and NIC rats of both sexes once a month from 2 to 7 months of age. At an early age, male but not female NIC rats, exhibited shorter analgesic responses to nicotine than did the matched controls. With increasing age, however, the duration of nicotine analgesia began to be prolonged in NIC rats of both sexes. Significant differences between control and NIC rats were found at the age of 6 and 7 months, in both sexes. Thus, rats prenatally exposed to nicotine are not born with an increased sensitivity to the analgesic effect of a single dose of nicotine. This phenomenon develops later, during the course of life, independently of gender.     

不同术后镇痛模式对红细胞免疫功能的影响

目的探讨不同术后镇痛模式对红细胞免疫功能的影响。方法50例妇科手术患者,按术后不同镇痛模式分为硬膜外自控镇痛(PCEA)组和静脉自控镇痛(PCIA)组。并分别于术前、术后1、3、7 d采静脉血样检测红细胞C3b受体花环率(RCR)、红细胞免疫复合物花环率(RICR)、红细胞免疫粘附促进因子(RFER)和红细胞免疫粘附抑制因子(RFIR)。结果与术前比,PCEA组术后1 d RCR、RFER显著上升(P<0.05),RFIR显著下降(P<0.05),术后3 d RCR、RFER仍显著上升(P<0.05),而RICR显著下降(P<0.05);PCIA组术后1 d RCR、RFER显著下降(P<0.05),RFIR、RICR显著上升(P<0.05);PCIA组术后1、3 d RCR、RFER比PCEA组显著降低(P<0.05),而RICR显著上升(P<0.05);两组各参数在术后7 d基本恢复至术前水平。结论PCEA对红细胞免疫功能的稳定和恢复作用明显强于PCIA。     

白细胞介素—2新的功能位点及其中枢镇痛作用

白细胞介素－２（ＩＬ－２）不仅是重要的免疫调节因子，而且还具有重要的中枢调节作用。本实验以钾离子透入引起大鼠甩尾反应为指标，发现侧脑室注射ＩＬ—２能显著提高动物痛阈，并能被纳洛酮所阻断，表示ＩＬ－２的中枢镇痛作用可能与阿片受体有关。利用基因定位突变技术获得的无免疫活性ＩＬ－２实查体仍具有中枢镇痛作用，表明ＩＬ—２分子上发挥镇痛和免疫调节作用的功能位点是相互独立的。纳洛酮能够阻断ＩＬ—２的中枢镇痛作用，而不能影响ＩＬ—２增殖ＣＴＬＬ－２细胞的作用，提示ＩＬ－２发挥镇痛和免疫调节作用可能通过不同的受体途径。ＩＬ－２分子中第４５位Ｔｙｒ残基突变为Ｖａｌ后，虽仍保留了免疫活性，但丧失了镇痛功能，表示４５位Ｔｙｒ残基是ＩＬ—２发挥中枢镇痛功能的关键残基之一。我们推测ＩＬ—２的镇痛功能位点可能在ＩＬ—２分子中第４５位Ｔｙｒ残基附近区域。     

Survey of postoperative analgesia following ambulatory surgery

Background: The quality of pain relief during the first 48 hours following ambulatory surgery has been poorly documented. This questionnaire study was performed to evaluate the nature and severity of pain after the patient leaves the hospital. Methods: 1100 patients in the age group 5–88 years who underwent ambulatory surgery during a period of 6months were asked to complete a questionnaire 48 h after the end of the operation. In thecase of children, parents were asked to complete a similar questionnaire. The questions were related to pain experienced during the first 48 h after surgery and to the nature andseverity of postoperative complications. Results: A total of 1035 out of the 1100 patients returned the questionnaire, 94.1%. Overall the majority (65%) of patients had only mild pain at home; however, patients undergoing certain types of surgery had moderate-to-severe pain: inguinal hernia surgery (62% patients), orthopaedic surgery (41%), hand surgery (37%) and varicose vein surgery (36%). In these patients the severity of pain did not decrease during the 2-day study period. About 10% patients had more severe pain than they had anticipated, and 20% had difficulty in sleeping at night due to severe pain. Despite this, over 95% of patients were satisfied with man-agement of postoperative pain. Nausea (20%), tiredness (20%) and vomiting (8%) were the commonest complications reported during the first 48 h. A significant association was found between the administration of a general anaesthetic and the incidence of nausea postoperatively. A large number of patients were alone at home after the operation (28.4%); some (3.8%) had no access to a relative or friend in case of need. Conclusion: Our results show that about 35% of day-surgery patients experience moderate-to-severe pain at home in spite of analgesic medication. About 20% of patients had sleep problems due to severe pain. However, only 5% of patients were dissatisfied. Better analgesic techniques are necessary for patients undergoing certain types of surgery. Patient information and follow-up routines need to be improved.     

环十五酮的抗炎和镇痛作用

本文报道环十五酮900mg/kg灌胃明显抑制小鼠耳壳二甲苯致肿。600mg/kg灌胃对大鼠足跖注射1％角叉菜0.1ml或鲜蛋清0.1ml致肿,也有明显消肿作用。用小鼠扭体法(皮下注射224、400、712mg/kg)、甲醛法(腹腔注射300mg/kg)和热板法(腹腔注射500mg/kg)测试,均证实环十五酮提高痛阈。镇痛时间比度冷丁、氨基比林长。     

Central effects of systemic lidocaine mediated by glycine spinal receptors: an iontophoretic study in the rat spinal cord

The objective of this investigation was to demonstrate the possible interactions of systemic lidocaine (lido) with inhibitory receptors in the spinal cord. In the lumbar dorsal horn of anesthetized and curarized rats, 60 physiologically identified, wide dynamic range (WDR) neurons, were recorded extracellularly. Glutamate, glycine and its selective antagonist, strychnine, were iontophoretically applied onto the neurons either singularly or concurrently. The effects of systemic lido on the drug-induced frequency changes and the interaction with the glycine receptors, using strychnine as a probe, were studied. It was consistently found that (i) lido (3–4 mg/kg) inhibited the excitatory responses to iontophoretic glutamate, (ii) this inhibition was significantly antagonized by concurrent iontophoretic strychnine, (iii) iontophoretic glycine induced comparable glutamate inhibition that was reversed by strychnine. In contrast, no effect on glutamate-induced excitations was observed when lido was applied by micropressure or a different local anesthetic was systemically administered. The results suggest that central inhibitory effects of lido could by mediated by spinal strychnine-sensitive glycine receptors, activated by lido itself or possibly by its glycine residue-bearing metabolites.     

小剂量吗啡在妇科术后镇痛中的临床应用

目的 :探讨小剂量吗啡用于妇科术后镇痛的效果。方法 :对 36 0例硬膜外麻醉行妇科手术的病人随机分组 ,198例病人在手术结束时硬膜外导管注入吗啡 2 mg(生理盐水稀释至 10 m L)、78例注入芬太尼 0 .0 4 m L(生理盐水稀释至 10 m L )、84例注入生理盐水 10 m L作为对照组。结果 :吗啡组 、 级镇痛达 86 .9% (172 /198) ,芬太尼组为 2 8.2 % (2 2 /78) ,生理盐水组为 (3/84 ) ;吗啡明显高于芬太尼组及生理盐水组 ,(P<0 .0 1)。而三组恶心、呕吐、呼吸、脉搏等副反应无明显差别。结论 :吗啡用于妇科术后镇痛效果好、安全、适用。     

桂枝镇痛效应的药理学研究

目的　探讨桂枝的镇痛作用。方法　采用热板法和扭体法观察该药的镇痛作用。结果　桂枝对小鼠热致痛和醋酸致痛均有明显的抗痛作用 ,与颅痛定镇痛效果比较均无显著差异 (P >0 .0 5 ) 。结论　桂枝具有镇痛效应 ,对临床应用、镇痛药开发具有借鉴和指导意义。