| Background:Chronic cerebral underperfusion,as a result of multiple diseases and as a cause of other diseases,is often impossible to intervene at the root of its onset and progressive exacerbation.Current conventional treatment is based on intervention of risk factors,treatment of the cause,improvement of cerebral circulation through medication,and increased cerebral perfusion through cerebral revascularisation.Cerebral revascularisation can effectively establish collateral circulation,improve cerebral tissue perfusion,prevent stroke and improve long-term neurological function,but the quantity and quality of postoperative vascular network construction is often inadequate.In order to effectively establish collateral circulation and explore new ways of treating cerebral ischaemia,various interventions and neuroprotective studies are gradually being carried out,but they are all in the experimental stage.Studies at home and abroad have shown that stem cells and vascular growth factors play a key role in promoting vascular renewal,among which platelet-rich plasma is a current research hotspot,but it is mostly focused on the field of orthopaedics and soft tissue repair,with less research in the treatment of cerebral ischaemic diseases.Objective:To investigate the safety and efficacy of platelet-rich plasma in SD rats with chronic cerebral ischaemia and to provide an experimental basis for the clinical treatment of chronic cerebral ischaemic diseases.Methods:1.The platelet-rich plasma was obtained by secondary centrifugation of rat peripheral blood using the"Landesberg"method.2.The SD rat model of chronic cerebral ischemia was prepared by a modified bilateral common carotid artery ligation method,and 2%TTC staining was used to determine whether the rat cerebral ischemia model was successfully prepared.3.After 3 weeks of model preparation,SD rats with chronic cerebral ischaemia were randomly divided into 4 groups(Group A:Sham group,Group B:Encephalo-myo-synangiosis group,Group C:Platelet-rich plasma group,Group D:Encephalo-myo-synangiosis+Platelet-rich plasma group)according to the Zea Longa neurological function score and Berderson score to assess the neurological function score of SD rats.4.Platelet-rich plasma or combined with Encephalo-myo-synangiosis was given after craniotomy to intervene in each group of rats with chronic cerebral ischaemia.5.The survival of each group of rats was recorded in detail,and SD rats in each subgroup were scored for neurological deficits according to the Neurological Impairment Scale(m NSS)method preoperatively and on days 7,14 and 21 postoperatively.6.On the 21st day after surgery,the brains of the rats were cut off and the concentrations of VEGF and FGF growth factor were measured by enzyme-linked immunosorbent assay,and the expression of CD31 was measured by immunohistochemistry to calculate the microvascular density.7.Using Image J software,the images were processed,the data analysed and plotted using SPSS 26.0and Graphpad Prism 8,and compared by statistical analysis to draw relevant conclusions.Results:1.The concentration of platelets in the peripheral blood of rats was 510.63±36.16×109/L as determined by the automatic hematocrit analyzer,and the concentration of platelets in the rat PRP obtained by the"Landesberg"secondary centrifugation method was 2602.41±86.18×10~9/L.The platelet enrichment ratio was greater than 5 times.The difference was statistically significant(P<0.001)and met the requirement of platelet enrichment,indicating that the"Landesberg"secondary centrifugation method could successfully obtain the desired concentration of PRP.2.A modified bilateral common carotid artery ligation method was used to successfully establish a model of chronic cerebral ischaemia in rats.After surgery,the rats showed various degrees of neurological deficits.1%TTC staining showed that the cortical and deep staining in the brain tissue of the model rats was between red pale and red,indicating that the brain tissue was ischemic and the modeling was successful.3.After the administration of PRP and temporalis muscle patching or combined intervention in randomly grouped SD rats that met the scoring requirements after moulding,survival analysis of the rats in each group suggested no significant difference by Log Rank(Mantel-Cox)comparison(χ~2=2.967,P=0.397).The neurological deficit scores showed that the neurological function scores improved in all groups at 7,14 and21 days after the intervention,with a statistically significant difference(P<0.05)between the m NSS scores of the EMS and EMS+PRP groups compared to the Sham group at postoperative day 7.At postoperative day14,the difference in m NSS scores between the EMS group and the Sham group was statistically significant(P<0.01),and the difference in m NSS scores between the PRP group and the EMS+PRP group was even more significant(P<0.001)compared with the Sham group.On postoperative day 21,the m NSS scores in the EMS and PRP groups were statistically significant(P<0.01)compared to the Sham group,and the differences in the EMS+PRP group were statistically significant(P<0.05)compared to the Sham,PRP and EMS groups,and the differences were significant(P<0.001)compared to the Sham group.4.The ELISA results showed that the VEGF expression in the EMS+PRP group was significantly higher than that in the Sham,EMS and PRP groups,and the difference was statistically significant(P<0.001),with the VEGF expression in the PRP group also statistically significant compared to the EMS and Sham groups(P<0.01).The difference was statistically significant(P<0.001)in the expression of FGF in the EMS+PRP group compared to the Sham group,and the difference was also statistically significant(P<0.05)compared to the PRP and EMS groups.The difference was also statistically significant(P<0.05)in the EMS and PRP groups compared to the Sham group.In the microvascular density by immunohistochemical CD31 staining,the EMS,PRP and EMS+PRP groups were all higher than the Sham group,and the difference was statistically significant(P<0.01).The EMS+PRP group was significantly higher than the EMS and PRP groups,and the difference was statistically significant(P<0.01).The difference was also statistically significant(P<0.05).Conclusion:PRP can safely and effectively improve neurological deficits in rats with chronic cerebral ischemia,and promote the expression of VEGF and FGF in brain tissue,which is conducive to neovascularization,and the effect is more obvious when combined with encephalo-myo-synangiosis. |
