The Empirical Study Of Changes Of NPY And NF-κB Following Fluid Percussion Brain Injury In Rat.

The trauma has already became the fourth death factor of mankind followed the cardiovascular disease,the malignant tumor,cerebral accident.The incidence rate of traumatic brain injury ranks first or second in all kinds of trauma,its lethality and mutilation rate is obviously higher than the wound of other body part.It is one of the primary causes which result the young people in disability and death.The mortality and mutilation rate of traumatic brain injury is high,resulting in the tremendous sufferings and economy bear for sufferer and their family,also bringing heavy burden for society.The thorough research the pathogenesis of craniocerebral trauma,inquire prevention and cure measure,there is important economic and social meaning.Neuropeptide Y(NPY) widely exists in the central nervous system,Neuropeptide Y is the important neuroendocrine modulato,participating various physiology functions to accommodate. NPY has direct constringency function to the blood vessel,it is the most vasoconstrictor effect polypeptide,results in the decline in cerebral blood flow,causes cerebral perfusion deficiency, further aggravates the brain tissue ischemia and hypoxia.Recent studies have shown that Nuclear Factor kappa Binding(NF-κB) closely related to traumatic brain injury,NF-κB activation is the committed step initiating cerebral trauma biochemical cascade,has the vital role in the physiopathologic developing process of traumatic brain injury.Objective The aim of this study was to explore the expression of neuropeptide Y as well as nuclear factor kappa binding in cerebral cortex and the change of neuropeptide Y in blood plasma,to investigate their roles in traumatic brain injury.Methods Observation of the fluid-percussion impact in brain injury model:168 adult Wistar rats were divided into two groups:experiment group(n =126) and control group(n=42). Experiment group is divided into 3 sub-groups,there are 42 rats in every group.The standard operating procedure was used in both experimental group and control group.For the control group we did not made fluid-percussion impact injury,the experiment made the rats into three types of traumatic brain injury models:mild,moderate and severe.The characteristics of general samples and pathology slice were observed.Blood plasma neuropeptide Y and Neuron-specific enolase concentrations were measured with enzyme-linked immunosorbentassay(ELISA) kit at 0.5,2,6,12,24,48 and 72h after brain injury.Cortex impingement of brain tissues were examined using immunohistochemical in order to study the distribution of NPY and NF-κB at the subcellar level.The data were analyzed by the SPSS for windows.Results(1) The traumatic brain injury models system above has the characteristics of precision of injury site,high stability of injury degree,better repeatability and little individual seldom error.The pathological change demonstrated that the higher hit intensity brings the more distinctive contusion,the more extent of subarachnoid and intracerebral hemorrhage,the more severe brain injury and edema,the high mortality.The brain injury and edema reach the fastigium in 24h and 48h.(2) The expressions of NPY in control group was at a low level,The expressions of NPY in the cortical injured region in experimental groups rats is higher than that of the corresponding period of the control group.NPY expression in the cortical injured region of experimental groups rats increases with the extent of damage increasing in 6h,12h,24h,48h and 72h.NPY expression of experimental groups rat start to increase significantly in 0.Sh.,in 2h, 6h andl2 h increases gradually,24h and 48h reach the peak,72h begin to decline.(3) The expressions of NF-κB in control group was at a low level,The expressions of NF-κB in the cortical injured region in experimental groups rats is higher than that of the corresponding period of the control group.NF-κB expression in the cortical injured region of experimental group rats increases with the extent of damage increasing in 24h and 48h.NF-κB expression of experimental groups rat start to increase significantly in 2h,in 6h andl2 h increases gradually, 24h and 48h reach the peak,72h begin to decline.(4) The concentrations of Blood plasma NPY in control group was at a low level,The concentration of NPY in blood plasma in experimental groups rats is higher than that of the corresponding period of the control group.The concentration of NPY in blood plasma in experimental groups rats increases with the extent of damage increasing in 6h,12h,24h,48h and 72h.The concentration of NPY in blood plasma s start to increase significantly in 0.5h,in 2h,6h,and12 h increases gradually,24h and 48h reach the peak,72h begin to decline.Conclusions(1) After the fluid percussion brain injury in rat,the pathological change demonstrated that the higher hit intensity brings the more distinctive contusion,the more extent of subarachnoid and Intracerebral hemorrhage,the more severe brain injury and edema, the high mortality.The brain injury and edema reach the fastigium in 24h and 48h.(2) The expression of NPY in the cortical injured region and the concentration of NPY in blood plasma in experimental groups rats increases synchronously after traumatic brain injury. The results suggest thai NPY increases with the extent of damage increasing in in the early stage after TBI,NPY may play an important role in the physiopathologic course after TBI.(3) The results suggest that NF-κB is up-regulated obviously in the early stage after traumatic brain injury,The expression of NF-κB in the cortical injured region of experimental groups rats increases with the extent of damage increasing in the crest-time of cerebral injury and edema.NF-κB may play an important role in the balance injury and anti-injury course after TBI.