The Research Of Relativity Between NGF Trk-A P75and Pathological Cicatircial Itching And Pain

Nerve growth factor (NGF) is the earliest neuropeptides that ever been found, it is alsoone of the most important biological active molecules in the nervous system, it is animportant factor to maintain the function of the nervous system, and can also promote thesurvival and differentiation of neurons, nourish mature neuron, to maintain its normalfunction, regeneration and functional restoration in the injured nerve. in scar formation, NGFand its receptor play an important role in the process of differentiation of Collagenprogenitor cells, it is not only related to collagen deposition in scar, it also has a closerelationship with pathological scar tickle, vitro experiments have demonstrated that NGF canpromote the mast cells degranulation of5-HT in wound tissue which is typical itch causingsubstances, promote the increase of Substance P. Neuropeptides, NGF can also change thenociceptor threshold of pain,leads the pain amplification, or idiopathic pain.Objective: This study uses HE staining technic, immunohistochemistry technic, toluidineblue staining technic, for detection of NGF and its receptor and degranulation of mast cells,in pathological scar with or without itching and pain. And analyze the relationship betweenNGF and pathological scar tiching and pain.Experimental methods: collect19samples of clinical pathological scar, divided into A, Btwo groups: A with pathological scar tickle, B without pathological scar tickle.All thesamples are fixed in the10%neutral formalin for at least48hours, routine gradient alcoholdehydration, paraffin embed and slice each sample into25sections, respectivelyhematoxylin-eosin (HE) staining（5）and immunohistochemistry (NGF, Trka, p753×5),toluidine blue staining (5). NGF and its receptor immunohistochemistry staining positivesignal will be the brown particles. NGF and its receptor, mast cell degranulation imageareanalysis method:1.observe NGF and its receptor positive samples under a400×microscope in each group, and manage with Image ProPlus6.0image analysis system.Choose5microscopic vision in each slice make average for comparison.2. Using the ImageProPlus6.0analysis system to analyze the expression intensity of NGF and its receptor and manage it with IOD values, choose5microscopic vision in each slice,observe and measuretheir average optical density, IOD value of each field, make their average value as theaverage optical density and IOD value of the samples respectively.3.Observe the result oftoluidine blue staining, observe mast cell degranulation degree, calculate the positive particlenumber, area, average optical density and integral optical density using ProPlus6.0imageanalysis system. Results:1.HE staining, observe pathological scar under the microscope,there are short columnar basal layer cells connected to dermal layer.The intercellularconnection is loose, a lot of deposition of collagen which is pink, darker, and more irregular,and there are few inflammatory cells near expanded capillary vessels. Fibroblast isrelatively developed, nuclear is small, deeper color, more weakly basophilic cytoplasm.2.NGF Immunohistochemical staining:pathological result: in scars with itching and painfulsymptom, the area, average optical density, integral optical density of the positive sanples ofNGF and its receptor Trka, p75number, was significantly higher than that of group withoutitching and pain symptoms, and there is statistical significance (p<0.05).3.In scar withitching and pain symptoms, the average area and amount.mean optical density, integraloptical density of mast cell degranulation positive sample was significantly higher than thescar without itching and pain, had statistical significance (p<0.05).Conclusion:1. the positive samples of NGF and its receptors exist in pathological scarswith or without pain and itching itch.2. In the scar with pain and itching symptom, NGF andits receptor Trka, p75positive sample amount is more, with higher density and deeper color,there is statistical significance.3. In scars with pathological itch and pain, mast cellderegulation phenomenon is obvious. There is statistical significance.With the further research on the role of NGF and its receptors in the non-central nervoussystem, clearing its formation in pathological scar and pathological itch and pain in the scar.Analyzing its mechanism with immunochemical technique, the research and thedevelopment of clinic medicine for pathological tiching and painful scar will be promotedgreatly. There will be a broader further for the application of NGF and its receptor.