| Background and objective:According to our researches atherosclerosis is the cardiovascular and cerebrovascular disease basis of pathogeny which is infringement of blood supply(such as atheromatous plaque)in arterial wall causing damage of it.Atherosclerosis is the number one killer of human health.At present,genetic,immune,inflammatory damage and infection are involved in the occurrence and development of AS,and the dysfunction of autonomic nervous system is closely related to the imbalance of vascular endothelial and immune function,which is a risk factor for AS.Some scholars have found that autonomic nervous dysfunction is earlier than vascular disease and the degree of disorder is positively correlated with the severity of the disease.However,the study also showed that the lesion was accompanied by the change of local nerve,but the specific mechanism is still not clarified.The current basic research showed that vascular intimal injury can lead to atherosclerosis has been confirmed,interestingly,recent research shows that lead to atherosclerosis and early in endometrial lesions can also be adventitial lesions.Research has revealed that early adventitial intervention contributes to delaying or terminating the process of AS.Therefore,in recent years,the basic research on AS disease is not only confined to the intima and media,but also gradually began to pay attention to the role of adventitia Barker et al.carried out a study on stripping rabbit carotid adventitia to induce intimal lesion,which had provided research thin Current basic research has suggested that vascular intimal injury can lead to AS;in addition,adventitial lesion can not only result in AS,but also precedes intimal lesion.Research has revealed that early adventitial intervention contributes to delaying or termineting the process of AS.Therefore,focus of basic research on AS has shifted from vascular intima and media to adventitia.Barker et al.carried out a study that vascular adventitial injury can lead to intimal hyperplasia lesions.Furthermore,basic immunohistochemical research has demonstrated that adventitia is dominated by noradrenergic fiber.Therefore,it is suggested in this research that influence of adventitial injury on sympathetic nerve may play an important role in the genesis and development of AS.The peripheral sympathetic nervous system can synthesize and secrete an enzyme activity product,tissue type plasminogen activator,and has a certain level of t-PA in circulating blood under physiological conditions.The damage of the nerve fibers and the damage of the peripheral sympathetic nervous system will affect the synthesis and release of t-PA.Therefore,in this study,we use the ApoE gene knockout mice to establish the model of carotid adventitia dissection,and t-PA was used as the research object to observe the role of vascular endothelial cells in intimal hyperplasia induced by adventitia injury.Carotid adventitia stripping model had been constructed in this research by virtue of ApoE knockout mouse.Meanwhile,intervention of injection of t-PA on mouse vascular adventitial injury-induced intimal hyperplasia lesion as well as expression of related proteins was observed.Methods:This experiment was constituted by experiment in vivo.ApoE knockout mice were treated as the objects of study in this experiment,model were randomly divided into 3 groups,which were normal control group,adventitial injury group and t-PA group(model group+ injection of t-PA at a dose of 156?g/day).To explore the feasibility of establishing the model of carotid adventitia dissection in mice,and to observe the effect of exogenous t-PA on intimal hyperplasia after sympathetic nerve and vascular injury.Carotid intimal hyperplasia in all experimental groups was observed.Carotid artery sections were stained with hematoxylin and eosin(HE),and observed under microscope.Expression level of tyrosinehydroxylase in tissue samples were detected by Western blot and fluorescent staining,vascular lesion composition were detected by immunohistochemistry staining.Results:(1)Collagenese digestion + micro-forceps dissection could damage mouse adventitia effectively.(2)Hyperplasia lesion could be seen in corresponding intima 2 weeks after adventitial injury,with the lesion component of smooth muscle cell.t-PA group could promote intima hyperplasia.(3)SM-a-actin immunohistochemical in control group results suggested that only positive expression could be seen in media,while no obvious positive expression region could be seen in adventitia and intima.Vascular intima and media in adventitia injury group and t-PA group were associated with positive expression.The main pathological component is smooth muscle cells.However,the lesion of t-PA group was significantly higher than that of adventitia injury group.(4)Compared with adventitia injury group,the fluorescence intensity of TH was increased in t-PA group.Compared with the control group,the fluorescence intensity of TH was increased in adventitia injury group.(5)The results of Western blot showed that the expression of TH protein was increased in the adventitia injury group compared with the control group,but the expression of TH protein in the t-PA group was weaker.Conclusions:(1)ApoE gene knockout mice were able to establish a model of atherosclerosis after adventitia dissection.(2)t-PA can promote the plaque area,as well as levels of norepinephrine in vivo,accelerate the progress of atherosclerosis. |
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