Model Foundation Of Experimentally Induced Through Vascular Compression In Neurogenic Hypertension

Hypertension is a common cardiovascular disease and a major global public health problem,China's adult prevalence rate of hypertension was 18.8%according to surveys conducted in 2002,there are about 1.6 million patients with hypertension. Drug treatment can not cure the disease from the root,in other wise.Essential hypertension are frequently-occurring diseases, its complications such as cerebral hemorrhage,cerebral infarction, heart disease,such as a serious threat to human health.Objective:The purpose is to investigate a method of establishing an experimental animal model of neurogenic hypertension by compressing vagus nerve which will be more similar to clinical counterparts in morphology and pathology,so as to provide experimental foundation for the research on the formation and also to offer a reliable animal model.Methods:Fifty health SD rats weighting 280-300g were divided into two groups randomly.1.Surgery group,25 rats; 2.Sham group,25 rats,Allthe experimental animals were interaperitoneal injected by 10%chloral hydrate(5mg·kg^-1). After conventional disinfectant of skin,cutting in the middle of about 3cm by ophthalomology scissors.Then separate sternocleidomastoid by ophthalmic tweezers.According to the median strictly,we can see white thrachea,and go trough along the left side of muscle fiber,deep carotid sheath can be seen, which has fluctuating vascular,also the white vague nerve,then tear the fiber membrance and separate the artery and the paralled vague nerve about 2cm by tweeres.After this,place an absorbable haemostat at the bottom of the vague nerve,using 5-0 catguts of chrome,which were cut into pieces about l-2mm, fully place around the nerve.Then put a moist sponge and wrape it.We must attach the vague nerve to the vascular. Observe it without active bleeding about 2minutes,close it. After disinfectant by iodophor alcohol 2 times,then place the rats in the restore box and obserse the breath,waiting for clear awareness.We make reoperations on the surgery group after feeding them 3 weeks.First,found the nerve and vascular in the way of the first operation,we can see the sponge and catguts of chrome have been absorbed.and the light red,thicken nerve,put a small polyster film about 1.5×1.5cm around the nerve and fluctuating vascular.then fix the muscle on left side and make tightly compression between them.On this way,we make the operation of rat model of hypertension.We investigate the blood pressure of all the rats in 1,3,6 week after operations of the two groups.Measuring the blood pressure,pulse rate by instrument ML125/RMBP,save the average datas after consecutive measurements 10 times.And measuring the Renin (PRA)-Angiotensin(AngⅡ)-Aldosterone(ALD) system.All rats were expressly removed the left vague nerves about 2cm after 2 days of physcigical activity.Fix and cut into ultra-thin slives, observe them on electron microscope specimens of Hitachi H2500.Results:1 Blood Pressure(BP)In surgery group,there are no signifficant difference in the first week after operation(P＞0.05),and more or less higher than. pre-operation group in the third week,.but have no stastistic difference(P＞0.05),and have significant difference in the sixth week(P＜0.01).In sham-operation group,there are no significant differernce among pre-and post-operation in 1, 3,6weeks(P＞0.05).Between two groups,there are no significant difference in 1week(P＞0.05),3week,but have significant difference in the sixth week(P＜0.01).(Table 1,Fig.7)2 Pulse rate(PR)In surgery group there are no significant differernce among pre-and post-operation in 1,3,6weeks(P＞0.05).In sham-operation group,there are no significant differernce among pre-and post-operation in 1,3,6weeks(P＞0.05).Between two groups,there are no significant differernce among pre-and post-operation in 1,3,6weeks(P＞0.05).(Table2,Fig.8)3 Renin(PRA)-Angiotensin(AngⅡ)-Aldosterone(ALD)In surgery group,there have significant difference in the sixth week(P＜0.05).In sham-operation group,there are no significant difference among pre-and post-operation in 1,3, 6weeks(P＞0.05).(Table.3,Fig.9.10.11) 4 The Observation Result by ElectronmicroscopeIn vascular compression group,vague nerve was edema and disorder of lamellar,Schwann cell membrane localized defects, the disappearance of mitochondrial fusion,cytoplasmic edema; (Fig.l2.13.14).In sham-operation group were no obvious changes in vague nerve.(Fig.15)Conclusions:1 This mechanism to establish the animal model is similar to the demyelination and vascular compression in REZ by vascular compression of neurogenic hypertension2 This method can provide relia bleanimal model and experimental basis for diagnosing disease and exploring new therapeutic ways for neurogenic hypertension.3 The method of the animal model can increase blood pressure in 6 weeks,the detection of blood can also confirm that the effect is reliable,scientific and feasible.4 The method of the animal model take a new way for neurogenic hypertension in research etiology and clinical diagnosis.