神经降压肽在脊髓前角的分布及其在神经病理痛中的作用研究

发布时间：2018-02-28 03:15

本文关键词： 神经降压肽神经病理痛脊髓前角　出处：《华中科技大学》2006年硕士论文　论文类型：学位论文

【摘要】： 神经降压肽(neurotensin,NT)是含有13个氨基酸残基的脑肠肽,广泛分布于哺乳动物中枢和外周神经系统以及胃肠道内,参与了众多的生物效应。在中枢神经系统中研究较多的是其对痛觉的调制作用。其中脊髓水平的神经降压肽主要来源于脊髓固有神经元内,具有明显的镇痛作用,并推测该镇痛作用是由其高亲和力受体( NTR1)或低亲和力受体(NTR2)介导的。已证实,脊髓前角和后角都含有神经降压肽,对后角神经降压肽的分布已有了较详细的报道,而对其在前角的分布却知之甚少。另外,参与痛觉调制的神经降压肽具体来自于脊髓的何种神经元亦不明确。本研究首先应用形态学方法观察了脊髓前角内神经降压肽的分布特点,再利用慢性压迫性坐骨神经痛模型观察脊髓前角和后角的神经降压肽在神经病理痛条件下有何变化,从而初步探讨了脊髓水平神经降压肽在痛觉调制中可能的机制。一.脊髓前角神经降压肽的分布本研究首先利用经典的尼氏染色法和标记乙酰胆碱酯酶的Karnovsky-Roots法来显示脊髓前角的运动神经元,再利用免疫组织化学技术应用神经降压肽抗体观察脊髓前角内神经降压肽免疫阳性神经元的分布特点,通过对二者的比较,结果发现: 脊髓前角神经降压肽免疫阳性细胞可分为大、小两种。其中大细胞主要分布在前角前外侧(第Ⅸ层),多为多极神经元或双极神经元,与尼氏染色和乙酰胆碱酯酶显色显示的脊髓前角运动神经元具有明显的一致性,可认为该类阳性细胞可能为运动神经元(包括α和γ神经元);小阳性细胞则散在分布于前角各个区域,除可能为调节性中间神经元外,尚不能推测该类阳性细胞为何种神经元。二.慢性压迫性坐骨神经痛模型的制备成年雄性SD大鼠随机分为模型组、假手术组和正常组。其中模型组大鼠通过5-0铬制羊肠线结扎单侧坐骨神经建立慢性压迫性坐骨神经痛模型,假手术组大鼠处理除未结扎神经外同模型组,正常组大鼠未做任何处理。采用意大利产UGO-BASILE 37300型辐射热测痛仪,以大鼠术侧后足抬腿潜伏期为其痛阈反映值,连续监测其痛阈及行为变化。结果发现: 模型组大鼠术后第一天即开始出现术侧自发抬足、舔足以及不敢持重等自发性疼痛和感觉异常现象,痛阈亦随之降低, 5-7天达到高峰,伴有足趾屈曲内翻等畸形,安静时卧于健侧,至13-14天上述现象逐渐消失,但足趾屈曲内翻以及跛行等畸形无明显恢复。假手术组大鼠无上述典型现象出现。三组大鼠偶有轻微自嗜症状。三.神经病理痛条件下脊髓水平神经降压肽含量上调正常状态下在脊髓水平给予外源性神经降压肽具有明显的镇痛效应。为探讨神经病理痛条件下脊髓水平内源性神经降压肽是否上调,本研究利用神经病理痛模型,应用免疫组织化学技术等形态学方法以及监测大鼠痛阈等行为学手段,分别在大鼠痛阈最低期(第七天)和恢复期(第十四天)观察模型组、假手术组和正常组大鼠脊髓腰膨大处神经降压肽的含量变化。结果发现: 1.在前角前外侧(含第Ⅸ层),模型组大型神经降压肽免疫阳性细胞数和阳性面积无论在第7天还是在第14天都与假手术组和正常组之间没有显著性差异,即在痛阈最低期和痛阈恢复期都没有明显变化;与其同一视野的小型阳性细胞,其细胞个数无论在第7天还是在第14天都与假手术和正常组之间有显著性差异(P0.01)即在痛阈最低期明显增多,至恢复期有所减少,但均高于假手术和正常组;在前角内侧(约在第Ⅷ层内),小型阳性细胞的细胞个数在第7天与假手术组和正常组之间有显著性差异(P0.01),但在第14天三组之间没有显著性差异,即在痛阈最低期前角内侧小阳性细胞也明显增多,至恢复期降到正常组水平。在脊髓其他部位(包括后角)小型阳性细胞的数量在三组之间没有显著性差异。 2.模型组大鼠在第7天其脊髓后角胶状质(SG)内的神经降压肽含量显著升高,呈明显的眉毛状结构,而在恢复期神经降压肽含量下降,眉毛状结构随之消失。在假手术组大鼠和正常组大鼠没有观察到这一现象。综上所述,本研究在核团水平和细胞水平观察了神经降压肽在脊髓前角的分布,初步认为脊髓前角运动神经元内(包括α和γ神经元)含有神经降压肽,另外神经降压肽还存在于前角某些调制性中间神经元内。神经病理痛条件下,脊髓后角胶状质内神经降压肽含量升高,同时前角含有神经降压肽的中间神经元数量上调,二者在形态学和行为学上具有一致性,因此可推断脊髓水平的神经降压肽在后角胶状质内参与了痛觉的调制,而该神经降压肽可能主要来自脊髓前角某些中间神经元内。
[Abstract]:Neurotensin (neurotensin, NT) is a brain gut peptide containing 13 amino acid residues, is widely distributed in mammalian central and peripheral nervous system and gastrointestinal tract, involved in numerous biological effects. More research in the central nervous system is made of pain. The spinal cord nerve antihypertensive peptides mainly derived from intrinsic neurons of spinal cord, has obvious analgesic effect, and that the analgesic effect is determined by its high affinity receptor (NTR1) or low affinity receptor (NTR2) mediated. Confirmed that the anterior horn of the spinal cord and the angle containing neurotensin, the distribution of neurotensin angle the
A detailed report, and its distribution in the anterior horn is poorly understood. In addition, the neurotensin neurons involved in pain modulation in the spinal cord from the specific is not clear. In this study we used morphological method to observe the distribution of the angle of neurotensin in the spinal cord, with chronic constrictive injury the observation model of neurotensin in spinal cord anterior horn and posterior horn of any changes in neuropathic pain conditions, so as to explore the probable mechanism of the spinal cord level of neurotensin in pain modulation.
The distribution of neurotensin in the anterior horn of the spinal cord
The Karnovsky-Roots method in the study of classical Nissl staining and acetylcholinesterase markers to show motor neurons in anterior horn of spinal cord, the distribution of neurotensin immunoreactive neurons in spinal cord anterior horn were observed by immunohistochemical technique of neurotensin antibody, through the comparison of the two results:
The anterior horn of spinal cord of neurotensin immunoreactive cells can be divided into large, small two. The cells were mainly distributed in the anterior horn of the anterolateral (Ninth layer), multi multipolar neurons or bipolar neurons and Nissl staining and acetylcholinesterase staining showed spinal motor neuron has obvious consistency, can as the cells into motor neurons (including alpha and gamma neurons); small positive cells scattered in the anterior horn of all regions, except possibly for the regulation of interneurons, still can not speculate the positive cells what kind of neurons.
Two. Preparation of chronic compression sciatica model
Adult male SD rats were randomly divided into model group, sham group and normal group. The rats in the model group by 5-0 chromic catgut ligation of unilateral sciatic nerve to establish chronic constrictive injury model, the rats in the sham operation group without nerve ligation treatment with the model group, the rats in the normal group without any treatment. The Italy UGO-BASILE 37300 radiation thermal dolorimeter, rat ipsilateral foot leg latency as the pain threshold value of continuous monitoring, the pain threshold and behavioral changes.
The results were as follows:
The rats in the model group after the first day of the operation side began to appear spontaneous lifting, abnormal phenomenon and not so serious licking spontaneous pain and feel pain also decreased, reaching a peak at 5-7 days, accompanied by toe flexion varus deformity and so on, quiet when lying on the contralateral side, to 13-14 days the phenomenon gradually disappear, but toe buckling and varus deformity had no obvious limp recovery. The rats in the sham operation group without the typical phenomenon. The three groups of rats from occasional minor symptoms.
Three. Up regulation of the level of neurotensin in the spinal cord under the condition of neuropathic pain
Under normal conditions the exogenous neurotensin has a significant analgesic effect given at the spinal level. To investigate neuropathic pain conditions of spinal cord levels of endogenous neurotensin is up-regulated, the neuropathic pain model, by means of immunohistochemistry and morphological methods and monitoring the pain threshold behavior in rats, respectively. The lowest threshold period (seventh days) and recovery period (Fourteenth days) to observe the content changes of the model group, sham operation group and normal group rat spinal cord lumbar enlargement of neurotensin.
The results were as follows:
1. in the anterior horn of anterolateral (including ninth layer), the model group of large neurotensin immunoreactive cell number and the positive area in seventh days or in Fourteenth days and between sham operation group and the normal group had no significant difference, which is in the lowest pain threshold period and the recovery of the pain threshold did not change significantly; small positive cells with the same vision, the number of cells in seventh days or fourteenth days in between the sham and normal groups had significant difference (P0.01) significantly increased in the lowest threshold period, recovery period has decreased, but were higher than those in the sham and normal groups; in the anterior horn medial (about Article VIII layer), there was significant difference between the seventh day and the sham operation group and the normal group number of cells with a small positive cells (P0.01), but no significant difference in the fourteenth days between the three groups, which was significantly increased in the minimum period before the small angle threshold to restore positive cells. The number of small positive cells in the other parts of the spinal cord (including the posterior horn) was not significantly different between the three groups.
2. rats in the model group on the seventh day of the spinal dorsal horn of substantia gelatinosa (SG) neurotensin content increased significantly, showing the apparent eyebrow like structure, while the decline in the period of neurotensin content recovery, eyebrow like structure disappears. In the sham operation group rats and normal rats did not observe this a phenomenon.
In summary, this study investigated the distribution of neurotensin in the spinal ventral horn in the nuclei and cellular levels, primarily that spinal cord motoneurons (including alpha and gamma neurons) containing neurotensin, and neurotensin also exist in anterior horn neurons. Some intermediate modulation of neuropathic pain conditions neurotensin content increased, horncinerea in spinal cord neurons increased at the same time, the middle anterior horn containing neurotensin, two are consistent in morphology and behavior, so it can be concluded that neurotensin levels of the spinal cord involved in pain modulation in the posterior horncinerea, the neurotensin may mainly come from some intermediate neurons in the anterior horn of the spinal cord.

【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2006
【分类号】：R363

【相似文献】