Ligustrazine inhibits high voltage-gated Ca~(2+) and TTX-resistant Na~+ channels of primary sensory neuron and thermal nociception in the rat:a study on peripheral mechanism

Objective Ligustrazine, also named as tetramethylpyrazine, is a compound purified from Ligusticum chuanxiong hort and has ever been testified to be a calcium antagonist. The present investigation was to determine the antinoci-ceptive effect of ligustrazine and, if any, the peripheral ionic mechanism involved. Methods Paw withdrawal Latency ( PWL) to noxious heating was measured in vivo and whole-cell patch recording was performed on small dorsal root ganglion (DRG) neurons. Results Intraplantar injection of ligustrazine (0.5 mg in 25μl) significantly prolonged the withdrawal latency of ipsilateral hindpaw to noxious heating in the rat. Ligustrazine not only reversibly inhibited high-voltage gated calcium current of dorsal root ganglion (DRG) neuron in dose-dependent manner with IC50 of 1.89 mmol/L, but also decreased tetrodotoxin (TTX) -resistant sodium current in relatively selective and dose-dependent manner with IC50 of 2.49 mmol/L. Conclusion The results suggested that ligustrazine could elevate the threshold of thermal nociception through inhibiting the high-voltage gated calcium current and TTX-resistant sodium current of DRG neuron in the rat.     

大鼠骶髂关节传入神经通路的实验研究

目的:通过逆行神经追踪法研究大鼠骶髂关节的传入神经通路。方法:30只雄性Sprague-Dawley大鼠随机分成非交感神经切除组(A组)和交感神经切除组(B组),每组15只,交感神经切除组切除左侧L1以下椎旁交感干。两组左侧骶髂关节注入30%的辣根过氧化物酶(HRP)20μl,72h后取出双侧的L1-S1背根神经节(DRG),TMB法染色后在光学显微镜下观察HRP阳性神经元细胞并计数。结果:两组左侧L1、L2背根神经节内HRP阳性神经元差异有显著性意义(P<0·05),B组HRP阳性神经元明显减少;左侧L3-S1背根神经节内HRP阳性神经元差异无显著性意义(P>0·05)。结论:L1-S1神经节含有支配同侧骶髂关节的传入神经元,同侧椎旁交感干可能是骶髂关节到L1-L2神经节重要的传入神经旁路,而不是到L3-L5神经节的传入旁路或重要的传入旁路。     

左旋布比卡因腰-硬联合阻滞在下肢手术的应用

目的探讨0.75%左旋布比卡因用于蛛网膜下隙阻滞的临床效果及安全性。方法随机选择ASAⅠ～Ⅱ级的40例骨科下肢手术患者(股骨干及髋关节大手术的患者),随机均分成两组:L组腰麻用药为0.75%左旋布比卡因15mg,容量为2.5ml;B组腰麻用药为0.75%布比卡因,剂量及容量同L组。术中必要时经硬膜外导管注入2%利多卡因。术中监测BP、HR、SpO2、RR的变化并观察围术期不良反应的发生。结果两组最高阻滞平面及到达时间、麻醉持续时间、肌松效果及达到最大肌松效果时间差异均无显著意义。两组均无神经系统的不良反应。结论0.75%左旋布比卡因用于腰-硬联合麻醉骨科下肢手术安全有效,效果与0.75%布比卡因相比差异无显著意义。     

Distribution patterns of transforaminal injections in the cervical spine evaluated by multi-slice computed tomography

Transforaminal injections are sometimes used for the diagnosis and treatment of painful conditions in the lumbar and to a lesser degree in the cervical spine. The technique is most often used when investigating/treating radiculopathy caused by degenerative disease. But how selective are the nerve root blocks? What possible structures other than the intended nerve root are affected from such injections? This study was undertaken in order to try to answer these questions, as no study focusing on the possible spread from the transforaminal selective nerve root blocks in the cervical spine has been performed earlier. In three groups of patients, each group including three patients, we injected three different volumes (0.6, 1.1 and 1.7 ml) with a transforaminal technique in the cervical spine. In all the injections, a small amount of contrast media was added. The spread of the injections were then investigated using multi-slice computed tomography with reconstructions. The imaging revealed a possible effect on other nerve roots than the intended ones when a larger volume was used for the root blocks. The spread was related to the injected volume as well as to local anatomy (size of foraminal area). In this study, only 0.6-ml injections could be accepted for being selective enough for diagnostic investigations.     

Use of paracervical analgesia for outpatient hysteroscopic surgery: A randomized, double-blind, placebo-controlled study

Twenty-five women receiving sedation for outpatient hysteroscopic polypectomy were injected with 0.25% bupivacaine 10 mL (paracervical group) and another 25 received the same volume of saline (control group) at the cervical fornix. Both groups were given target-controlled propofol sedation during the procedure. More propofol (mg/min) was needed for adequate anesthesia in the control group compared to the paracervical group (6.5 versus 4.6). In addition, the postoperative pain scores were lower in the paracervical group than in the control group. Hemodynamic changes and postoperative side effects were similar in the two groups. This prospective, randomized, double-blind, placebo-controlled study confirmed the effective use of paracervical blocks. This approach has the effect of reducing the amount of intraoperative propofol and decreasing postoperative pain in outpatient hysteroscopic surgery.     

Stereoselectivity of actions of the calcium sensitizer [+]-EMD 60263 and its enantiomer [-]-EMD 60264

The thiadiazinone derivative [+]-EMD 60263 ((+)-5-(1-(α-ethylimino-3,4-dimethoxybenzyl)-1,2,3,4- tetrahydroquinoline-6-yl)-6-methyl-3,6-dihydro-2H-1,3,4 -thiadiazine-2-on) is a Ca²⁺-sensitizing agent with only minor phosphodiesterase inhibitory activity. Our aim was to characterize the inotropic and electrophysiological effects of [+]-EMD 60263 and its enantiomer [-]-EMD 60264 in several cardiac muscle preparations. The Ca²⁺-sensitizing activity resided in the [+]-enantiomer only. [+]-EMD 60263 (3 μM) shifted the EC₅₀ of Ca²⁺ for contractile activation of skinned fibers of pig heart from 2.41 μM to 0.73 μM, whereas [-]-EMD 60264 (30 μM) was ineffective. In Langendorff-perfused guinea pig hearts, [+]-EMD 60263 and [-]-EMD 60264 induced concentration-dependent positive and negative inotropic effects, respectively; both enantiomers reduced spontaneous heart rate but did not influence perfusion pressure. The maximum increase in force of human atrial trabeculae was 35 % of pre-drug control with [+]-EMD 60263 in comparison to 113 % with forskolin. In guinea-pig papillary muscles, [+]-EMD 60263 and [-]-EMD 60264 had opposite inotropic responses, however, both agents similarly prolonged action potential duration. Both enantiomers concentration-dependently blocked the rapidly activating component I_Kr of the delayed rectifier in guinea-pig myocytes. The block saturated at potentials positive to +30 mV, closely resembling the effects of the antiarrhythmic agent E-4031 which had been originally used to define I_Kr. It is concluded, that the positive inotropic action of [+]-EMD 60263 can be explained by prevalence of the Ca²⁺-sensitizing effect. The accompanying prolongation in action potential duration is caused by block of the I_Kr component of the delayed rectifier. While the inotropic effects are stereoselective, most of the electrophysiological actions are clearly independent of sterical configuration. The combination of Ca²⁺-sensitizing with class-III antiarrhythmic action may provide an interesting pharmacological profile of potential therapeutic use. Received: 7 January 1997 / Accepted: 25 February 1997     

艾司洛尔预注射对预防颈丛阻滞后心血管副反应的观察

颈丛阻滞常可引起心率增快 ,血压增高 ,被认为是颈动脉窦及迷走神经被阻滞 ,交感神经活性增强所致 [1 ]。我们采用艾司洛尔预注射的方法 ,抑制颈丛阻滞后的心血管副反应 ,取得了良好的效果 ,现介绍如下。1　临床资料和方法1.1　一般资料　选择 ASA I～ 级 ,择期行甲状腺瘤或囊     

颈丛阻滞、硬膜外阻滞下甲状腺手术应激反应的比较

目的 :比较颈丛阻滞、硬膜外阻滞下甲状腺手术应激反应的大小。方法 :选择ASAⅠ～Ⅱ级 ,女性 ,甲状腺手术患者 30例 ,年龄 2 2～ 5 5岁 ,术前无呼吸、循环和内分泌疾病 ,随机分为颈丛阻滞组 (颈丛组 ) 15例 ,硬膜外阻滞组(硬膜外组 ) 15例 ;颈丛阻滞选用 0 .8%利多卡因和 0 .2 5 %布比卡因混合液 ,以C4一点法行双侧深浅丛阻滞 ;硬膜外阻滞选用 1.3%利多卡因和 0 .15 %丁卡因混合液 ,穿刺点选择C4～ 5或C5～ 6间隙 ,采用侧卧位直入法 ,并向头置管 3cm ;分别测定并记录麻醉前、麻醉后 2 0min、切皮、分上极、切腺体和术毕共六个时点的血糖、血压和心率的变化。结果 :两组病例各时点血糖均逐步上升 ,于分上极、切腺体和术毕血糖值与麻醉前比较有显著性差异 (P <0 .0 1) ;硬膜外组只在分上极时SBP与麻醉前比较有差异外 (P <0 .0 5 ) ,而颈丛组在分上极、切腺体时DBP与麻醉前比较有差异 (P <0 .0 5 ) ,SBP、MAP与麻醉前比较有显著性差异 (P <0 .0 1)。结论 :本研究表明颈丛阻滞、硬膜外阻滞均不能完全抑制甲状腺手术的应激反应 ,在稳定甲状腺手术循环功能方面硬膜外阻滞优于颈丛阻滞     

完全性左束支传导阻滞伴快速心房纤颤并急性左心衰竭的抢救

目的总结完全性左束支传导阻滞伴快速心房纤颤并急性左心衰竭的治疗经验,以提高抢救成功率.方法对经抢救治疗的完全性左束支传导阻滞伴快速心房纤颤并急性左心衰竭9例(16次)患者进行治疗方面的回顾分析.结果9例(16次)患者14次抢救成功,成功率87.0%,但复发率较高,预后较差,有5例患者在抢救时或出院后1～2年内猝死.结论该组患者经传统"强心、利尿、扩血管",控制心房纤颤、心室率等治疗是远远不够的.应在未发生肺泡性肺水肿及心源性休克之前,尽早尽快地应用血管扩张剂及联合应用小剂量非洋地黄类正性肌力药物,并维持治疗24～72 h.其中以酚妥拉明加多巴胺和(或)多巴酚丁胺效果可能较佳,血管扩张剂硝酸酯类不及α-受体阻滞剂酚妥拉明疗效明显.     

臂丛神经阻滞加用地塞米松和小剂量吗啡用于术后镇痛的效果观察

目的 观察臂丛神经阻滞的局麻药液中加入地塞米松和小剂量吗啡用于术后镇痛的效果和副作用。方法 80例患者随机分为A、B、C、D四组。全部用肌间沟法臂丛神经阻滞，A组（n=20)注入0.5%布比卡因、2%利多卡因等量混合液25ml；B组（n=20)注入A组用药加地塞米松10mg(2ml)；C组（n=20)注入A组用药加吗啡2mg(0.2ml)；D组（n=20)注入A组用药加地塞米松10mg(2ml)、吗啡2mg(0.2ml)。结果 B、C、D组与A组相比起效时间显著缩短、镇痛时间显著延长，差异非常显著（P＜0.01)；而D组和B、C组相比镇痛时间又明显延长，差异非常显著（P＜0.01)；C组中有1例（5％）因发生恶心呕吐，其余多组无并发症发生。结论 臂丛神经阻滞的局麻药液中加入地塞米松和小剂量吗啡用于术后镇痛，镇痛时间长，效果可靠，副作用少，操作方便，经济实用。