脊髓中血管紧张素Ⅱ的释放及其抗电针镇痛

本文采用放射免疫分析方法测定不同频率电针引起大鼠脊髓液中血管紧张素Ⅱ（ＡⅡ）免疫活性（ｉｒ）的变化,并观察阿片受体在其中起的作用。结果表明：（１）２Ｈｚ电针时大鼠脊髓灌流液中ＡⅡ－ｉｒ减少２０％,但无统计学意义;１５Ｈｚ电针使满足流液中ＡⅡ－ｉｒ降低６２％（Ｐ〈０．０１）;１００Ｈｚ时ＡⅡ－ｉｒ增加６０％（Ｐ〈０．０５）。（２）脊髓蛛网膜下腔（ｉ．ｔ．）注射阿片受体拮抗剂纳洛酮后,１５ＨＺ电针反使     

电针频率对大鼠脊髓灌流液中SOM和CGRP含量的影响

本研究采用放射测定法,分析不同频率电针刺激下大鼠脊髓流液中抑制素（ＳＯＭ０和降钙素基因相关肽（ＣＧＲＰ）放免活性（ｉｒ）的变化。电针频率选择２,１５和１００Ｈｚ,分别收集电针前、中、后各３０ｍｉｎ脊髓灌流液进行测定,实验结果如下：（１）低频（２Ｈｚ）电针使脊髓脊流液中ＳＯＭ－ｉｒ水平升高３９％（Ｐ〈０．０５）,ＣＧＲＰ－ｉｒ降低４７％（Ｐ〈０．０５）;（２）中频电针（１５Ｈｚ）则相反,使ＳＯＭ－ｉ     

脊髓中P物质参与电针镇痛的研究

本研究发现,低频（２Ｈｚ）电针刺激时大鼠脊髓中Ｐ物质免疫活性（ＳＰ－ｉｒ）含量减少,中频（１５Ｈｚ）、高频（１００Ｈｚ）和变频（２／１５Ｈｚ）刺激时ＳＰ－ｉｒ含量增多。脊髓蛛网膜下腔（ｉ．ｔ．）注射非肽类ＳＰ（ＮＫＩ）受体拮抗剂ＣＰ９６３４５和ＲＰ６７５８０均能阻断中频、高频和变频的电针镇痛。ｉ．ｔ．注射阿片拮抗剂纳洛酮阻断低频和中频刺激时ＳＰ－ｉｒ含量的变化。结果提示,脊髓ＳＰ－ｉｒ在低频时释放     

不同频率电刺激膈神经导致膈肌肌浆网Ca~(2 )-ATPase和Ca~(2 )释放-摄取动力学改变

研究不同频率慢性电刺激（ＣＥＳ）后兔膈肌肌浆网（ＳＲ）Ｃａ２＋－ＡＴＰａｓｅ活性以及ＳＲ Ｃａ２＋摄取－释放动力学对不同频率ＣＥＳ的适应性变化。建立不同频率ＣＥＳ组;用定磷法测定ＳＲ Ｃａ２＋－ＡＴＰａｓｅ活性;用Ｆｕｒａ－２荧光法测定ＳＲ　Ｃａ２＋摄取－释放动力学。与对照组比较,慢性低频电刺激１０ Ｈｚ和２０Ｈｚ组的ＳＲ　Ｃａ２＋－ＡＴＰａｓｅ活性明显降低（Ｐ＜０．０１）,Ｃａ２＋释放－摄取动力学也显著降低（Ｐ＜０．０１）;慢性高频电刺激５０ Ｈｚ和１００Ｈｚ组的ＳＲ Ｃａ２＋－ＡＴＰａｓｅ活性则显著升高（Ｐ＜０．０１）,Ｃａ２＋释放－摄取动力学亦明显升高（Ｐ＜０．０１）。实验提示,ＣＥＳ后不同频率ＣＥＳ导致膈肌ＳＲＣａ２＋－ＡＴＰａｓｅ、Ｃａ２＋摄取－释放动力学产生不同的适应性变化;对不同功能状态的膈肌应用不同频谱的慢性电刺激可能具有重要的临床意义。     

导水管周围灰质微量注射阿片肽拮抗剂阻断甲醛致痛时脊髓背角P物质的变化

在大鼠脚掌注射福尔马林溶液后（２．５％,０．４ｍｌ）,在中脑导水管周围灰质内微量注射纳洛酮或β－内啡肽抗血清。用免疫组织化学方法结合计算机图像分析技术,观察到脊髓背角Ｐ物质样免疫阳性物质在福尔马林＋载液组的光密度（３．４２０８±０．４６２８）高于单纯载液组（１．５１８９±０．１４６５）,Ｐ＜０．０１;福尔马林＋纳洛酮组（１．８７０７±０．６６６４）与福尔马林＋β－内啡肽抗血清组（１．８５４７±０．７５３７）均明显低于福尔马林＋载液组,Ｐ＜０．０５;单纯注射纳洛酮或β－内啡肽抗血清组无明显变化。结果表明,导水管周围灰质内微量注射纳洛酮和β－内啡肽抗血清可以易化动物脚掌注射福尔马林引起的痛反应,并阻断脊髓背角Ｐ物质的增加。提示伤害性刺激可以引起中脑导水管周围灰质内β－内啡肽的释放,与相应的阿片受体作用,调制脊髓背角Ｐ物质的释放。     

福尔马林致痛后大鼠中脑导水管周围灰质甲啡肽及脊髓背角P物质含量的变化

本文用免疫组化方法结合计算机图像处理技术观察大鼠后脚掌皮下注射福尔马林后脊髓背角Ｐ物质免疫阳性反应（ＳＰＬＩ）变化的节段性分布及中脑导水管周围灰质（ＰＡＧ）内甲啡肽样免疫阳性反应（ＭＥＬＩ）的变化。结果显示,注射福尔马林后,脊髓腰段（Ｌ１－２,Ｌ４－５）背角ＳＰＬＩ显著增强（Ｐ＜．０５）,３０ｍｉｎ组与６０ｍｉｎ组相比较无显著变化（Ｐ＞０．０５）;胸脊髓（Ｔ８）无显著变化（Ｐ＞０．０５）;颈脊髓背角ＳＰＬＩ有增强趋势（０．０５＜Ｐ＜０．１）;ＰＡＧ中ＭＥＬＩ减弱,腹外侧部３０ｍｉｎ组比６０ｍｉｎ组变化更大（Ｐ＜０．０５）。ＰＡＧ中ＭＥＬＩ与脊髓背角ＳＰＬＩ变化的时相关系提示福尔马林致痛引起的脊髓背角Ｐ物质的增多可能与ＰＡＧ中甲啡肽及阿片受体活动有关。     

新生大鼠脊髓薄片中的运动神经元对腹外侧索刺激的反应

在新生大鼠脊髓薄片细胞内记录了２５个经送行刺激鉴定的运动神经元（ＭＮ）,发现腹外侧索刺激可在８０％的ＭＮ诱发去极化反应（ＥＰＳＰ）。在静息电位水平ＥＰＳＰ的潜伏期、达峰时间、幅度、半衰时间和时程分别为１．２±０．２ｍｓ,２．６±０．４ｍｓ,１３±３ｍＶ,５．３±１．６ｍｓ和３１±８ｍｓ。ＥＰＳＰ呈等级性和膜电位依赖性,平均翻转电位为－８ｍＶ,潜伏期在０．—５Ｈｚ频率的刺激时相对恒定,但刺激频率＞２０Ｈｚ时ＥＰＳＰ变小或被取消。ＥＰＳＰ在低钙高镁溶液中被阻抑叵在无镁溶液中增强。犬尿烯酸（０．５—１ｍｍｏｌ／Ｌ）可逆地阻断ＥＰＳＰ,但氯胺酮（５０—１００μｍｏｌ／Ｌ）仅部分抑制之。结果表明腹外侧索中的下行纤维可能释放兴奋性氨基酸而激活ＭＮ。     

刺激大鼠视上核后电针“足三里”对蓝斑灌流液中去甲肾上腺素含量的影响

运用行为测痛结合蓝斑（ＬＣ）灌流液去甲肾上腺素（ＮＥ）的高压液相（ＨＰＬＣ）测定；观察 大鼠痛阈（ＰＴ）与ＬＣ灌流液中去甲肾上腺素含量变化间的相互关系，结果表明：（ｌ）视上核 （ＳＯＮ）内注射 １０μｍＬ－谷氨酸（Ｌ－ｇｌｕｔａｍｉｃａｃｉｄ， Ｌ－Ｇｌｕ）后 ３０分钟，大鼠ＰＴ较注射前增加１３３． ２± ２１．４％，此时ＬＣ 灌流液中ＮＥ含量从注射前的４３７．３±２０．４ｎｇ／ｍｌ降到２２９．２±１１．９ｎｇ／ｍｌ，注射 后６０分钟ＰＴ仍比注射前高８３．９±１４．７％，而灌流液中ＮＥ的含量为３２８．６±２８．０ｎｇ／ｍｌ，与人工 脑脊液（ＡＣＳＦ）对照组相比有非常明显的差别（Ｐ＜０．０５～０．００１）。（２） ＳＯＮ注射Ｌ－Ｇｌｕ后，电 针足三里３０分钟（Ｌ－ＧＩＵ＋ＥＡ组）增加到注射前的１８８．２±２３．９％，同ＡＣＳＦ电针组（ＡＣＳＦ＋ ＥＡ）的 ９４．９±７．１％相比有明显差异（Ｐ＜０．０１）。此时ＬＣ灌流液中ＮＥ的含量虽较注射前都明显 降低、分别为１３７．６±７．５ｎｇ／ｍｌ和 １５１，１±１１．５ｎｇ／ｍｌ，但两者相比无明显差异。停针后３０分钟Ｌ－ Ｇｌｕ＋ＥＡ组的ＰＴ仍比注射前高１３３．８±２７．９％，明显高于     

中药764—3对内毒素所致离体大鼠灌流肺损伤的保护作用探讨

本研究观察了大肠杆菌内毒素对大鼠离体灌流肺的氧化性损伤作用,并探讨了中药７６４－３对该损伤的保护作用。结果发现单纯离体灌流肺给予内毒素刺激未能引起肺动脉升高,这与在体情况下的反应不同。内毒素组的肺泡灌洗液中蛋白质含量和肺组织湿干重比值分别比其它组为高（Ｐ＜０．０５）,该组肺组织匀浆和肺泡灌洗液中丙二醛（ＭＤＡ）含量也显著高于其它组（Ｐ＜０．０１）。中药７６４－３能够显著地减轻肺水肿（Ｐ＜０．０５）     

电剌激及心肌缺血所致豚鼠心脏神经肽Y释放变化的研究

电剌激豚鼠心脏左星状交感神经节,可引起钙依赖性的神经肽Ｙ（ＮＰＹ）胞外释放,缺血１０ｍｉｎ后行电刺激（Ｓ２）,与对照期（Ｓ１）比较,ＮＰＹ释放无明显变化,缺血２０ｍｉｎ后行电剌激,ＮＰＹ释放受到一定程度的抑制,（Ｓ２／Ｓ１：０．７２,Ｐ＜０．０５）,而再灌注５ｍｉｎ后行电剌激ＮＰＹ释放抑制作用逐步消失,与Ｓ１比较,已无明显减少（Ｓ２／Ｓ１;１．０１,Ｐ＞０．０５）。仅缺血无电剌激几乎不引起ＮＰＹ释放。这些结果提示,电剌激交感神经节可致ＮＰＹ呈现一种钙依赖性出胞释放,缺血早期ＮＰＹ释放受到某些代谢产物抑制,恢复再灌注后,代谢产物逐步冲洗出,抑制作用也随之消失。     

Differential Release of Endogenous 5-Hydroxytryptamine, Substance P., and Neurokinin A from Rat Ventral Spinal Cord in Response to Electrical Stimulation

Abstract: The release of endogenous 5-hydroxytryptamine (5-HT), substance P (SP), and neurokinin A (NKA) from superfused tissue slices of rat ventral lumbar spinal cord, where SP and NKA coexist with 5-HT in terminals of descending bulbospinal neurons, was investigated. Electrical field stimulation was performed using square-wave pulses of 2-ms duration and 30 mA stimulus intensity. The following four different patterns of stimulation were used: 2 Hz continuous, 20 Hz continuous, 20 Hz intermittent, and 50 Hz intermittent. 5-HT was measured in the slice superfusates by HPLC with electrochemical detection. SP and NKA were measured by radioimmunoassay. The release of 5-HT was significantly enhanced using all stimulation paradigms and the evoked release of 5-HT per pulse was independent of the stimulation frequency. The release was found to be calcium dependent and there was no increase in the efflux of 5-hydroxyindoleacetic acid in response to stimulation. At 2 Hz (continuous), no significant increase in the release of SP was observed. Stimulation at higher frequencies yielded a significant increase in the release of SP per pulse. At 20 Hz, the release was increased by 73% (continuous) and 74% (intermittent), and at 50 Hz (intermittent) by 175% of basal efflux. The evoked release of NKA was also frequency dependent. At 2 Hz (continuous), no significant increase in the release of NKA was observed. At 20 Hz (intermittent), the evoked release per pulse was increased by 33% and at 50 Hz (intermittent) by 53% compared with the basal efflux of NKA. The results suggest that coexisting neurotransmitters/neuromodulators in the spinal cord may be released in different proportions depending on the stimulation frequency and that only 5-HT is released when the nerve terminal is activated by low-frequency stimulation.     

High and low frequency electroacupuncture analgesia are mediated by different types of opioid receptors at spinal level: a cross tolerance study

Previous studies have shown that rats subjected to low or high frequency electroacupuncture (EA) stimulation release enkephalins or dynorphins respectively to produce analgesia. This conclusion was tested in the present study by using cross tolerance technique for further analysing their receptor mechanisms. The main results were as follows: (1) In rats subjected to 2 Hz EA for 6 h, there was a gradual decrease in the analgesic effect, leading to a state of tolerance to 2 Hz EA analgesia. These rats, however, still responded to 100 Hz EA. Likewise, rats made tolerant to 100 Hz EA were still effective to 2 Hz EA stimulation, showing not significant cross tolerance between 2 Hz and 100 Hz EA analgesia. (2) Rats made-tolerant to 100 Hz EA analgesia showed a diminished response to intrathecal dynorphin A (1-13), a kappa agonist, whereas the analgesic effect of the delta agonist [D-Pen2, D-pen5] enkephalin (DPDPE) remained intact. (3) Rats made tolerant to 2 Hz EA analgesia showed a cross tolerance to DPDPE, but not to dynorphin A (1-13). Results obtained from aforementioned cross tolerance studies suggest that 2 Hz and 100 Hz EA analgesia are mediated by delta and kappa opioid receptors, respectively, at the spinal cord of the rat.     

Ovarian blood flow responses to electroacupuncture stimulation depend on estrous cycle and on site and frequency of stimulation in anesthetized rats.

Electroacupuncture (EA) applied to the abdomen and hindlimb modulates the ovarian blood flow (OBF) response. The present study aimed to further elucidate the role of the site and the frequency of short-term EA stimulation and the influence of the estrous cycle on the OBF response using anesthetized rats. EA stimulation was applied to the abdominal or the hindlimb muscles at three different frequencies (2, 10, and 80 Hz) during the estrus or diestrus phase. Involvement of spinal and supraspinal reflexes in OBF responses to EA stimulation was investigated by spinal cord transection. Abdominal EA stimulation at 10 Hz increased the OBF response, whereas hindlimb EA stimulation at 10 Hz and abdominal and hindlimb stimulation at 80 Hz decreased the OBF response; 2-Hz EA caused no OBF response. The OBF response to abdominal EA was more pronounced in the estrus than the diestrus phase. The OBF response to abdominal and hindlimb EA stimulation at both 10 and 80 Hz was almost abolished, both after severance of the sympathetic nerves and after spinal cord transection. In conclusion, the OBF response to both abdominal and hindlimb EA stimulation was mediated as a reflex response via the ovarian sympathetic nerves, and the response was controlled via supraspinal pathways. Furthermore, the OBF response to segmental abdominal EA stimulation was frequency dependent and amplified in the estrous phase.     

Differences in neural-immune gene expression response in rat spinal dorsal horn correlates with variations in electroacupuncture analgesia

Background

Electroacupuncture (EA) has been widely used to alleviate diverse pains. Accumulated clinical experiences and experimental observations indicated that significant differences exist in sensitivity to EA analgesia for individuals of patients and model animals. However, the molecular mechanism accounting for this difference remains obscure.

Methodology/Principal Findings

We classified model male rats into high-responder (HR; TFL changes >150) and non-responder (NR; TFL changes ≤0) groups based on changes of their pain threshold detected by tail-flick latency (TFL) before and after 2 Hz or 100 Hz EA treatment. Gene expression analysis of spinal dorsal horn (DH) revealed divergent expression in HR and NR after 2 Hz/100 Hz EA. The expression of the neurotransmitter system related genes was significantly highly regulated in the HR animals while the proinflammation cytokines related genes were up-regulated more significantly in NR than that in HR after 2 Hz and 100 Hz EA stimulation, especially in the case of 2 Hz stimulation.

Conclusions/Significance

Our results suggested that differential regulation and coordination of neural-immune related genes might play an important role for individual variations in analgesic effects responding to EA in DH. It also provided new candidate genes related to EA responsiveness for future investigation.     

电针刺激可在大鼠脊髓诱发Fos样蛋白的生成

本研究利用Fos蛋白的免疫组织化学方法首次报道电针“三阴交”穴位可在大鼠脊髓诱发原癌基因c-fos的表达。电针后大量Fos免疫反应(FLI)细胞出现在脊髓腰膨大的背、腹角,但标记最密集区为背角Ⅲ,Ⅳ层。在动物足部注射福尔马林产生的伤害性刺激亦可在脊髓腰膨大背、腹角诱发大量FLI细胞,但以背角Ⅰ,Ⅱ层标记最为密集。因此电针和伤害性刺激引起的脊髓c-fos表达在分布上是不同的。电针诱发的Foc蛋白可能参与针刺镇痛。     

Left vagal stimulation induces dynorphin release and suppresses substance P release from the rat thoracic spinal cord during cardiac ischemia

Electrostimulatory forms of therapy can reduce angina that arises from activation of cardiac nociceptive afferent fibers during transient ischemia. This study sought to determine the effects of electrical stimulation of left thoracic vagal afferents (C(8)-T(1) level) on the release of putative nociceptive [substance P (SP)] and analgesic [dynorphin (Dyn)] peptides in the dorsal horn at the T(4) spinal level during coronary artery occlusion in urethane-anesthetized Sprague-Dawley rats. Release of Dyn and SP was measured by using antibody-coated microprobes. While Dyn and SP had a basal release, occlusion of the left anterior descending coronary artery only affected SP release, causing an increase from lamina I-VII. Left vagal stimulation increased Dyn release, inhibited basal SP release, and blunted the coronary artery occlusion-induced release of SP. Dyn release reflected activation of descending pathways in the thoracic spinal cord, because vagal afferent stimulation still increased the release of Dyn after bilateral dorsal rhizotomy of T(2)-T(5). These results indicate that electrostimulatory therapy, using vagal afferent excitation, may induce analgesia, in part, via inhibition of the release of SP in the spinal cord, possibly through a Dyn-mediated neuronal interaction.     

不同频率电针刺激对神经痛模型大鼠脊髓背角P物质的影响

目的:观察P物质(Substance P,SP)在慢性坐骨神经压迫损伤(chronic constriction injury,CCI)模型脊髓中表达的变化,探讨电针镇痛的机制是否与脊髓背角中SP表达的变化有关。方法:选择32只雄性、体重180-200 g的SD大鼠,并将其随机均分为4组(n=8)。空白组(Con组)为正常痛阈值大鼠;假电针组(CCI+A组)在损伤的坐骨神经旁置入电针,但无电流刺激;2 Hz组和100Hz组分别给予相应频率电流刺激30 min。在实验开始前和术后1、4、7、14、20、22天记录大鼠的热缩足反射潜伏期(Paw Withdrawal Latency,PWL)和机械刺激缩足反射阈值(Paw Withdrawal Threshold,PWT)。免疫组化方法检测脊髓背角SP的表达。结果:术后20天,电针治疗后,100 Hz组和2 Hz组PWT分别为(7.33±1.42)g和(7.80±1.42)g,均显著高于假电针组(2.60±1.46)g,差异有统计学意义(P0.05)。100 Hz组在术后20天后和2 Hz组在术后14天后PWL值均显著高于假电针组,差异有统计学意义(P0.05)。免疫组化显示:2 Hz组和100 Hz组大鼠脊髓背角中P物质阳性细胞显著低于假电针组(P0.05)。结论:坐骨神经旁电针刺激能够显著减轻CCI模型大鼠热痛觉及机械痛觉过敏,其机制可能与抑制脊髓背角SP的表达有关。