| Erythropoietin (EPO) is a acidic glycoprotein containing sialic acid, with water-soluble, consists of165amino acids. Is a cytokines to regulate blood cell production and differentiation, mainly from the kidney and fetal liver; Only the role of precursor cells in bone marrow megakaryocytes, stimulating the red progenitor cells and the early erythroblast formation of mature red blood cell colony. The bioiogical role of erythropoietin (EPO) is mediated through the surface receptor of the target cell membrane. Recent studies show that erythropoietin (EPO) as a novel multifunctional neuroprotective agent, with significant neurotrophic, neuroprotective and to promote the growth and development of nerve. Spinal ganglion is the accumulation area of Sensory nerve cell bodies, consisting of false unipolar neurons and a direct relationship with limbs feeling function.The repairation of dorsal root ganglion(DRG), has been the very difficult problem of medical profession. When peripheral nerve injury how to promote repairation and regeneration of peripheral nerve, improving neurological function, has been the goal of basic and clinical research. The aims of this experiment is to explain the function of recombinant human erythropoietin (rhu-EPO) to repair the lumbar ganglion damagation. To provide new treatments for clinical that promote the recovery of the peripheral nervous system. Provide a theoretical basis for the exogenous rhu-EPO to treat lumbar ganglion injury.Methods:Forty-five healthy SD rats were used, weighing200to250g, either male or female, were divided randomly into sham operation group, control group and rhu-EPO treatment group (n=15). Sham operation group only exposure the sciatic nerve; control group off the sciatic nerve in the piriform10mm, with the same volume of0.9%saline injection daily; rhu-EPO treatment group off the sciatic nerve and inject rhu-EPO (recombinant human erythropoietin)3000IU/kg every day. After one week, two weeks, three weeks intubating through left ventricle to the ascending aorta to perfusion-fixed. To the the foraminal direction of retrograde tracing along the sciatic nerve, opening the lamina. Spinal nerve roots can be determined and the spinal ganglion which is swelling. Take the general observation,toluidine blue staining, hematoxylin-eosin staining of DRQto observe pathological changes, local inflammatory reaction and Caspase-3-positive rate measurement and the detection of apoptosis.Results:After sciatic nerve of rat was transected, the lower limb of operative side lost the function of motor, obvious limp;the phenomenon of swelling、spreading out、 thinning of skin、 smooth,etc,emergenced during one week. The above phenomenon was gradually increased.The phenomenon of ulcers and clear exudate in foot appeared during the next week, rats chewing on their own toes and part of the toes missing During the third week the foot ulcers aggravated with clear exudate, the rat paw, together with the distal leg missing, local muscle atrophy, toe swelling obviously; After the secend and the third week, the rhu-EPO treatment group’s neurogenesis diameter of proximal nerve was thick compared with the control group. Foot ulcers in rats slightly alleviate than in the control group in toes missing and there is not significant improvement.1. Nissl stainingThe neurons of Normal control group stained deep;the outline of the cell is clearly;cell bodies are filled with fine sand and granular Nissl bodies; After sciatic nerve is transected the spinal ganglion neurons darkly stained in the control group; Compared with the sham group the number of neurons is reduced, some neurons stained contour unclear and turn pale; dorsal root ganglion neurons in rhu-EPO treatment group stained paler than in the sham group, pathological of spinal ganglion neurons changes significantly.At the second week and the third week pathological changes significantly improved in the spinal ganglion neurons compared with the untreated group.2. HE stainingThe sham operation group is no abnormalities. In the control group neuronal cell bodies of dorsal root ganglion is extensive edema and vacuolar changes significantly;the number of neurons is also reduced, lightly staining. Neurons that individual typical apoptosis exist in isolation occasional with the condensation state: concentrated cytoplasm, nucleus shrinkage, nuclear chromatin and higher density concentrated into a dense granular cohesion in the nuclear membrane, the axon is not obvious, but the membrane integrity, cytoplasm orange clearly and deeply stained, the volume of the cell body shrinkaged and deformated, halo around the cells, at the first week, the second week, and the third week the phenomenon became clearly and the injury severly; spinal ganglion neuron cell body edemas in rhu-EPO treatment group mitigate compared with the control group, at the first week, cell swelling, cell body shrinkage deformation and the cell body halo obvious, apoptotic cells exist occasionally., after the second and the third week, edema and vacuolar changes significantly reduced and the neurons deeply stained, positive cells reduced.3. Test results of Caspase-3The test results of control group show that caspase-3positive staining is brown, glial cells take the large part, spinal ganglion neuron cell bodies are also positive cells. Sham operation group, no or only see a small number of positive cells.rhu-EPO treatment group casepase-3positive cells were significantly lower than the control group (P<0.05). The positive rate is higher in with rhu-EPO treatment at the first week and cells withered obviously, at the second week the positive expression of the cells is reduced significantly, at the third week only see a few positive cells and lighter staining; The control group deeply stained and the number of caspase-3positive cell was gradually increased over time, indicating that the injuries were aggravated. Rhu-EPO can inhibit the apoptosis of dorsal root ganglion neurons and promote the recovery of neurological functConclusions:(1)The transection of Sciatic nerve can cause retrograde degeneration of spinal ganglion neuron; It is the peak of apoptosis at one week and can be detected at different stages of the apoptotic cells and typical apoptotic bodies.(2)The recombinant human erythropoietin (rhu-EPO) has an important neurotrophic role on inhibitting apoptosis and promoting the recovery of neurological function of the lumbar ganglion neurons.(3)Suggesting that the early application of erythropoietin (EPO) is essential to restore nervous system function after peripheral nerve injuried... |
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