Study On Dopamine Transmitter Content Change In Brain Paraventricular Nucleus And The Relation Between Renal Nerve And Renal Hypertension

Objective: establishment of renal typertension model; adopting rats brain orientation, microdialysis and electrochemical measuring technique were used to establish brain nuclei nerve transmitter content measurement method. Comparing the artery blood pressure change and dopamine content in brain paraventricular nucleus of rats renal hypertension model between renal nerve retaining group and renal nerve removing group, to make clear the effect of renal nerve in the occurring process of renal hypertension and the relation of dopamine content in paraventricular nucleus and renal hypertension occurrence, so as to provide basis for clarifying the effect of heart-renal reflection in the occurring development of renal hypertension. Method:(1) establishment of renal hypertension rats model: a 0.25 mm acupuncture needle was selected and placed in left renal artery, ligatured with it. After that, the needle was drew out to cause left renal arterial stenosis. After operation, the arterial blood pressure of rats was monitored for 4-6 weeks, and when diastolic pressure was higher than 100 mm Hg, it indicated that the establishment of renal hypertension rats model was successful.(2) Study on effect of renal nerve in renal hypertension rats model: 18 SD rats were grouped into three groups randomly:①Renal nerve removing group: the left renal artery was separated and contracted, and then theleft renal nerve was clipped. After operation, caudal artery noninvasive blood pressure measurement instrument was adopted to observe dynamic change of rats artery blood pressure. ②Renal nerve retaining group: the left renal artery was separated and contracted, but left renal nerve was retained. After operation, caudal artery noninvasive blood pressure measurement instrument was adopted to observe dynamic change of rats artery blood pressure. ③Blank control group: simulate operation process and the rest observation was the same with experiment group.(3) Measurement of dopamine transmitter content in paraventricular nucleus of rats: a needle cannula was embedded in paraventricular nucleus of anesthetized rats. Under waking state, microdialysis technique was adopted to collect extracellular fluid dialyzatein in paraventricular nucleus of rats. High performance liquid chromatographyelectro- chemical detection(HPLC-ECD) was used to detect dopamine content in dialyzate of paraventricular nucleus of renal hypertension rats. All the data were presented in mean±standard deviation(x ± S), variance analysis and pairing t-testing, it had statistical significance when P﹤0.05. Result:(1) establishment of renal hypertension rat model: 0.25 mm silver needle making left renal artery stenosis can well copy renal hypertension model. Its arterial blood pressure was still presenting a high level state, with systolic pressure reaching 152.33 mm Hg, diastolic pressure reaching 119.05 mm Hg. No calcification, atrophy or necrosis was found in the renal during dissection.(2)The effect of renal nerve on blood pressure of renal hypertension rat model:atfirst week, the blood pressure of rats in the experiment group and the control group increased; compared with that of the blank control group, the blood pressure of removing renal nerve model group and retaining renal nerve model group increased evidently and the difference had significance; the blood pressure of retaining nerve group was more evident than that of removing renal nerve group; two weeks after operation, the blood pressure of the blank control group recovered to that level before operation; compared to that of blank control group, the blood pressure of removing renal nerve model group and retaining renal nerve model group increased continuously, and the difference had significance.(3) Measurement of dopamine transmitter content in paraventricular nucleus dialyzate of rats: dopamine transmitter content in paraventricular nucleus dialyzate of rats; dopamine transmitter content in paraventricular nucleus of renal hypertension model rats in renal nerve removing group and retaining group decreased evidently, and the difference had statistical significance. Dopamine transmitter content was negatively related to hypertension rats model level. Conclusion: a certain degree of renal artery stenosis can establish steady renal hypertension model. Removing renal nerves can decrease blood pressure level of renal hypertension. Paraventricular nucleus dopamine transmitter system can directly or indirectly participate in blood pressure regulation of renal hypertension and is related to renal nerve activities.