| Research ObjectiveIn recent years,solid organ transplantation,cardiovascular interventional surgery and coronary artery bypass surgery have been widely carried out,these procedures have some common characteristics,whether it is the transplant organs,metal stents,or autologous vein graft,they are all cause a strong inflammatory response after surgery.Organ transplantation is an effective way to treat end-stage organ failure,but exotic grafts can cause a strong rejection and inflammatory response,and the grafts will also affect the state of the host;in interventional surgery,the implantation of metal stent won't cause a strong rejection,but will lead to aseptic inflammation;as for the coronary artery bypass surgery,although the bypass blood vessels are often taken from the autologous veins,the venous arterialization will still take place after the operation,and a complex inflammatory response are also involved.Therefore,people have been gradually pay attention to the various types of rejection and inflammatory responses in postoperative hosts on grafts and the various adverse effects of grafts on hosts.Whether the grafts can maintain a long-term stable function and the long-term quality of life of hosts have been a major clinical obstacle.Statins are currently used as a treatment for lowering blood lipids in clinical practice.In recent years,studies have found that statins have certain effects in anti-inflammatory,anti-oxidative,delaying atherosclerosis and even reversing atherosclerotic plaque.Therefore,it's a new idea that whether can we use statins as the resistance to the various adverse effects of grafts on hosts.It is necessary to establish an animal model to try to focus on the adverse effects of grafts on the hosts.We try to construct the model of allogeneic arterial transplantation in rats and try to explore the effects of atorvastatin as a resistant on the adverse effects of the grafts on recipient animals.And we hope our research may provide a certain theoretical basis to further researches and even more clinical applications of statins.Experimental Methods1.The Establishment of Animal Model:6-8 weeks old male SD rats and Wistar rats were selected as model animals.The rats were weighing 200-250g,SD rats were donors and Wistar rats were used as recipients.10%chloral hydrate with the dose of 0.004ml/g intraperitoneal injection anesthesia,SPF transplantation operating room,all the operations are right common carotid artery orthotopic transplantations.Surgeries are completed under microscope by single individual.2.The Evaluation of Animal Model:body weight of rats,serum inflammatory factors,serum lipid levels and transplanted arterial morphological changes were selected as observation targets.We established the transplantation group(n = 5)and control group(male Wistar rats,n = 5).In TO(preoperative or control observation day 0),T7(postoperative day 7 or control observation day 7),T30(postoperative day 30 or control observation day 30),T45(postoperative day 45 or control observation day 45)and T60(postoperative 60 days or control observation day 60),data were collected from the above observation targets.3.Formal Experiment:Group 1:select male Wistar rats body weight 200-250g in normal feeding as usual,set group 1 as Control Group(n = 4).Transplantations was still with clean male SD rats as donors,clean male Wistar rats as recipients.To prevent the bad influence of postoperative animals got accidental death,surgeries will undergo 12 pairs.Group 2:rats are all from post-operation animals,without the use of atorvastatin intervention,but with ultra-pure water gavage,which the capacity is equal to the drug suspension from group 3,set group 2 as the Transplant Control Group(n = 4).Group 3:rats are all from post-operation animals,with a high-dose atorvastatin treatment,drug dosage:10mg/kg/d,medication:atorvastatin and ultra-pure water suspension gavage,set group 3 as Transplant + Treatment Group(n =4).Similarly,data were collected from the above observation targets in T0,T7,T30,T45 and T60.4.Data Analysis:use the IBM statistical software SPSS 24.0 for corresponding statistical analysis,use the Graph Pad Prism 7.0 for statistical charts.Experimental Results1.Construction and evaluations of the animal model:in this part of the experiment we tried to construct an animal model of inflammation and dyslipidemia caused by transplantation,and the result was not bad.The data of body weight,serum inflammatory factors and blood lipid levels were all from T0,T7,T30,T45 and T60 these 5 different time points.Therefore,the Analysis of Variance of Repeated Measurement Data was selected as the statistical method.The changes of body weight in the two groups showed that the weight gain of the rats after transplantation was significantly higher than that of the control group,the comparison between groups was statistically significant(P<0.01).The results of inflammatory factors showed that the levels of TNF-a and IL-6 in the serum of the transplanted rats were significantly higher than those in the control group(P<0.01).Both serum TNF-a and IL-6 showed two growth peaks,the first one was seen within one week after surgery,which may reflect the graft-induced acute rejection,the second one was seen after a slow rising in two months,which may reflect the chronic rejection from host immune system on graft.The serum triglyceride(TG),total cholesterol(TC)and low density lipoprotein cholesterol(LDL-C)were significantly higher in the transplanted rats than those in the control group,showed a clear increasing trend.The changes of the above three in the control group were relatively gentle and maintained within the normal range,results of the comparison between groups were statistically significant(P<0.01).The result of high density lipoprotein cholesterol(HDL-C)showed no significant difference between the two groups(P>0.05).Specific reasons may be related to inflammation,immunological exclusion and still need more in-depth study.Morphological changes are also in line with expectations,although oil red O staining failed to show a clear atherosclerotic plaque,but the orange staining part of the arterial intima still showed the lipid deposition,and this change is basically consistent with changes in blood lipids.In this part of the experiment,we have successfully constructed a model for studying the adverse effects of grafts on recipient animals after transplantation.Although there was immune rejection,it does not affect the survival of recipient animals seriously.2.Results and evaluations of atorvastatin treatment:through high-dose atorvastatin for 60-day's gavage treatment of arterial transplantation rats,we found that high-dose statins not only have an effective lipid-lowering function,but also showed a great anti-inflammatory property,whether the inflammatory factors,or the morphological changes were all support this result.The levels of serum TNF-a and IL-6 in the Transplantation + Treatment Group were significantly lower than those in the control group(P<0.01),and the levels of blood lipids in this group was significantly lower than that in the control group(P<0.01).In this part of the experiment,we made it clear that statins played an important role in resisting the adverse effects of grafts on hosts besides the traditional strong lipid-lowering effect.Conclusion1.In this study,we have successfully constructed an animal model to study the adverse effects of grafts on hosts after transplantation.But the model still exists the following disadvantages:the skills of surgery is kind of hard to handle,the mortality rate is a little bit higher.2.Statins have an obvious effect in reducing the inflammatory response after transplantation and resisting the adverse effects from grafts on hosts.However,the results of animal experiments can only be used as a reference,the real clinical diseases are more complex,and we still need more extensive and in-depth studies to understand the exact mechanism of statins. |
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