The Experimental Study On Therapeutic Efficacy Of Focal Irrigation By ACSF On Severe Traumatic Brain Injury In Rats

Background and objective:In the published experimental results of our research group have showed that the effects of focal irrigation by ACSF and focal mild hypothermia on brain edema and apoptosis after traumatic brain injury.But,if there is any injury in normal brain tissue after focal irrigation by ACSF,the effect of time in focal irrigation,the specific regulating mechanism of nerve cell apoptosis by ACSF'S irrigation,are unclear.Furthermore,the curative effect still have not confirm in the animal clinical level.Through detecting the content of water,Na⁺,K⁺,EB,the apoptosis of nerve cell,the expression of VEGF,P-ERK,TNF-a and the oberservation of electron microscope afer intervention in STBI;the aims of this expriment are following:â‘ If there is any injury in normal brain tissue after focal irrigation by ACSF.â‘¡the effect of focal irrigation's time in TBI.â‘¢The possbile regulating mechanism of nerve cell apoptosis by ACSF'S irrigation.â‘£To affect the rat's fatality rate and Neurological dysfunction after focal irrigation by ACSF.TO provide more useful clues for the clinical application of ACSF. The partâ… :The empirical study about if there is any injury in normal brain tissue after focal irrigation by ACSF.Methods:Seventy seven healthy adult Sprague-Dawley rats were randomly separated to normal group(N group),sham operation group(SO group),Focal irrigation by normal saline(NS group),Focal irrigation by ACSF(ACF group).Groups were divided into 2 subgroups in different time points(12h,3d).Every subgroup and normal group have six rats.Each subgroup was measured for the content of water,Sodium,Potassium and examined with electron- microscopy.Other 5 rats in each subgroup were measured EB-content.Result:1.The content of water,EB and ion in brain tissue:The content of water,Sodium,Potassium and EB in brain tissue at 12 hr,3d after focal irrigation by ACSF comparing with N group and SO group has no significantly difference(P＞0.05).The content of water,Sodium and EB in brain tissue after focal irrigation by NS was significantly higher than N group,SO group and ACF group at 12h,3d.The changes of Potassium content was reverse.2.Pathological changes:SO group and ACF group have no obvious edema in periphery of blood capillary,no abnormalty in neurn and glial cell.but NS group has mild changes in those cytoarchitectonics mentioned above.Conclusion:1.Focal irrigation by ACSF has no damage to normal brain tissue.2.Focal irrigation by NS has some damage to normal brain tissue. The partâ…¡The influence of curative effect about the time for focal irrigation by ACSF in TBI.Methods:Two hundred and forty healthy adult Sprague-Dawley rats were randomly separated to sham operation group(SO group),traumatic brain injury animal model group(TBI group),focal irrigation by ACSF for 3hr(FI_3h group),focal irrigation by ACSF for 6hr(FI_6h group),focal irrigation by ACSF for 9hr(FI_9h group).The animals were sacrificed at 12hrs and 1,3,7 days posttrauma.Groups were divided into four subgroups according to the four time points(n=12 in each subgroup).Each subgroup(n=6) was measured for the content of water, Sodium,Potassium and examined with electron- microscopy.Moreover, the protein expression of VEGF was detected by Immunohistochemisty in each subgoup(n=6).Results:1.water and ion content,the protein expression of VEGF:Water content of TBI group,FI_3h group,FI_6h group and FI_9h group was increased at the 12h,the peak value appeared at 1-3d after TBI,that compared with SO group have obvious difference at 12h,1d,3d(P＜0.05);then,went back to normal levels at 7d compared with SO group(P＞0.05).At 12h,1d and 3d after cerebral trauma,the water contents of FI_3h group,FI_6h group and FI_9h group were all lower than TBI group(P＜0.05);FI_6h group was lower than FI_3h group(P＜0.05),FI_9h group was lower than FI_6h group(P＜0.05).The changes of sodium content and protein expression of VEGF were in parallel with the content of water.but the change of Potassium content was reverse.2. Pathoiogieal changes:In terms of damaged neurons and destroyed BBB,TBI group was more obvious than FI_3h group,FI_6h group and FI_9h group.Conclusion:1.Irrigation by ACSF can inhibit the protein expression of VEGF.2.To extent the time of focal irrigation by ACSF can lessen brain edema.The partâ…¢Irrigation by ACSF affect the apoptosis of nerve cell by the path of ERK after TBIMethods:One hundred and ninety two healthy adult Sprague-Dawley rats were randomly separated to sham operation group(SO group),traumatic brain injury animal model group(TBI group),focal irrigation by ACSF group(ACF group),focal irrigation by normal saline(NS group).The animals were sacrificed at 6,12hrs and 1,3days posttrauma.Groups were divided into four subgroups according to the four time points(n=12 in each subgroup).The protein expression of P-ERK2 was detected by western blot in each subgroup(n=6).Moreover,the protein expression of VEGF was detected by Immunohistochemisty, Apoptosis in impact site were detected by terminal deoxynucleotidyl transferase-mediated nick end labeling(TUNEL). Relsult:1.The protein expression of p-ERK2:The expression increased at 6hr in TBI group,ACF group and NS group,got the peak value at 12hr,and decent at 1d,but still higher than SO group at 3d(P＜0.05).The relations of the protein expression of P-ERK2 at all time points:ACF group＜NS group＜TBI group(P＜0.05).2.The protein expression of TNF-a:The expression increased at 6h in TBI group,ACF group and NS group,got the peak value at 1d,was higher than SO group at 3d(P＜0.05).The relations of expression at each time point:ACF group＜NS group＜TBI group(P＜0.05).3.TUNEL-positive cells in injured brain tissue:TUNEL-positive cells were seldom in SO group, TUNEL-positive cells in other groups were significantly higher than SO group at 6h,12h,ld and 3d posttrauma(P＜0.05),and the peak value appeared at 1d posttrauma.The relations of TUNEL-positive cells in groups:ACF group＜NS group＜TBI group(P＜0.05).Concision:1.Focal irrigation by ACSF can inhibit apoptosis of nerve cells by the path of ERK.2.The effect of inhibitting apoptosis by focal irrigation by ACSF was stronger than NS.The partâ…£:Irrigation by ACSF affect mortality and neurological Severity of rat after TBIMethods:Thirty six healthy adult Sprague-Dawley rats were randomly separated to sham operation group(SO group),traumatic brain injury animal model group(TBI group),focal irrigation by ACSF group(ACF group),n=12 in each group,Modified neurological Severity Scores(mNSS) and Beam walking test(BWY) was measured at 1d,3d,7d,14d,28d,The mortality was added up at 7d after TBI.Result:1.Modified neurological Severity Scores:The score was high at 1d posttrauma and then gradually degraded, The score of ACSF group was lower than TBI group at 3d,7d posttrauma(P＜0.05);but has no obvious difference at 1d,14d,28d(P＞0.05).2.The times of beam walking test:The times of TBI group and ACF group were longer than SO group and preoperation(P＜0.05) and have no obvious difference at 28d posttrauma(P＞0.05).The time of TBI group was longer than ACF group at 3d,7d,14d(P＜0.05).but has no obvious difference at 1d,28d.3.The angles of angling test:The angles of TBI group and ACF group were smaller than SO group and preoperation(P＜0.05) and have no obvious difference at 28d posttrauma(P＞0.05).The angle of TBI group was smaller than ACF group at 3d,7d,14d(P＜0.05).but has no obvious difference at 1d,28d 4.mortality:The mortality of ACF group has no obvious diffierence than TBI group.Conclusion:Focal irrigation by ACSF can facil recovery of neurological dificiency of rat after TBI.