| Pain is one of the serious problems of human health biomedical problems, has been widely recognized as " a disease." Pain evoked diverse factors and tables disease, in addition to the site of injury in the body continued to perform spontaneous pain, hyperalgesia and primary lesion surrounding area of secondary hyperalgesia occurs outside the site of injury, where the segment with the contralateral symmetrical parts somites are also so-called " mirror image pain. " Presented persistent pain, chronic, personalized multi-level restricts clinical prevention, diagnosis, treatment and effective selection strategy. In recent years, despite the pain associated with the regulation mechanism of the rapid development and transformation of medicine,climaxes, but still a lack of such complex table mirror hyperalgesia disease occurs, the system development and maintenance of mechanisms to understand.Multi-party evidence that the dopamine D2 receptor(DRD2), gap junction intercellular communication, glial cells may participate in the regulation of pain through different channels, but about its interaction mechanism remains to be elucidated. This paper hyperalgesia in experimental animal models mirrored preliminary simulation scorpion sting pain caused by natural phenomena based on clinical constructed by plantar subcutaneous injection of rat poison Buthus Martensii main ingredient-scorpion toxin peptide-specific sodium channel modulators Bm K I, using behavioral science, real-time quantitative PCR, immunoblotting and immunofluorescence and other experimental techniques to explore the peripheral and central DRD2, connexin Connexin 43(Cx43),glial cells and mirrors image pain occurs, develop and maintain relevance, build DRD2-Cx43 signaling pathways regulating the mirror image pain molecular and cellular mechanism of knowledge innovation system. The main results were as follows :( 1) DRD2 blockers and gap junction inhibitor-induced pain behavior on Bm K IIV synergistic inhibition : The rats were injected subcutaneously with unilateral plantarBm K I, can induce sustained spontaneous pain, injection ipsilateral thermal hyperalgesia and mechanical allodynia and contralateral mirror mechanical hyperalgesia. Intrathecal injection of a single pre-DRD2 antagonist raclopride or gap junction uncoupler Carbenoxolone(CBX) could significantly inhibit Bm K I induced spontaneous pain and mechanical mirror hyperalgesia while raclopride injection showed significant and CBX synergistic inhibition enhanced. In contrast, pre-given alone DRD2 agonist Quinelorane the enhanced Bm K I induced spontaneous pain, pain caused by presenting strengthened.These results suggest that the spinal cord and dorsal root ganglia are involved in the DRD2 and Cx43 Bm K I induced pain, development and maintenance of the regulation,and the two have a close expression profiles and cell signaling pathways linked.(2)Differences in the spinal cord DRD2 and Cx43 expression mirroring hyperalgesia relevance: RT-PCR showed that, intrathecal raclopride make contralateral DRD2 m RNA overall level down. Compared with the control group, the treatment group contralateral Cx43 m RNA increase. Western blot analysis showed, KI DRD2 protein levels were injected side first and then decreased, to a lesser extent, the sudden increase in the contralateral 24 h. Compared with the KI group, treatment group injected protein side is significantly reduced overall, but the opposite trend showing a significant increase.Treatment group injected side Cx43 protein levels gradually increase at any time away,showing the opposite trend downward. Bilateral administration group astrocytes marker GFAP protein levels are reduced. Bilateral group administered protein marker Iba1 microglia were also significantly reduced. Immunofluorescence showed, DRD2 and Cx43 total mark in astrocytes and microglia also has a significant expression. The results showed that the bilateral differences in spinal DRD2 and Cx43 expression mirroring hyperalgesia occurs, is closely related to the development and maintenance, and regulation of protein expression of Cx43 openness and change is one of the important mechanisms involved in the mirror DRD2 hyperalgesia.(3)Dorsal root ganglion DRD2 and Cx43 expression differences mirrored hyperalgesiarelevance : RT-PCR results showed that compared with the KI group, the overall level of the administration group DRD2 m RNA down the contralateral side increases. Compared with the control group, the treatment group injected side Cx43 m RNA levels rose after the first drop, the increase in contralateral 8h place. Immunofluorescence showed that,DRD2 colocalization with Cx43, and is abundantly expressed on the satellite glial cells,microglia. Administration group DRD2 and Cx43 injection side raised a total of scalar,multi- dose group bilateral DRD2 and satellite glial cells were co-labeled volume down.Administration group DRD2 and microglia co scalar raised, showing the first increase and then decreased. Also DRD2 and a lot of large-diameter neurons total mark, but less so with Non-peptide neurons altogether. These results suggest that the dorsal root ganglion DRD2 regulate Cx43 on glial cells play an important role in pain.(4) Live cell imaging studies DRD2-Cx43 cell signaling pathway: get isolated and subcultured acute spinal glial cells, using live cell confocal microscopy imaging techniques to verify that neurotransmitter dopamine can activate glial gap junction channel opening and makes extracellular Lucifer yellow into the cell, And the effect can be inhibit respectively by DRD2 blockers raclopride or gap junction blocker CBX. The results show that, DRD2-Cx43 intracellular signaling pathways directly mediated glial cells dopamine stimulation response.Conclusion : The spinal cord and dorsal root ganglion glial cells DRD2-Cx43 signaling pathways in injury side and contralateral temporal differences asymmetric expression changes involved in the mirror hyperalgesia, development and maintenance of the regulation. |
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