一种新的高盐致高血压动物模型及其血管重构改变

Establishment of new hypertensive rat model induced by high salt diet and research on changes of arterial remodeling in model

目的 :研究单纯高盐饲养对正常Wistar大鼠血压及血管结构的影响 ,并建立一种新的高盐致高血压大鼠模型。方法 :雄性Wistar大鼠 ,于哺乳期 (3周龄 )后 ,随机分成 2组 :正常盐 (含 0 .5 %NaCl饲料 )饲养组和高盐 (含 4 %NaCl饲料 )饲养组 ,持续饲养 18周 ,定期测量鼠尾收缩压和体重。实验结束时 ,经右颈动脉插管测平均动脉压。在血管灌注固定后 ,胸主动脉、肾动脉及肠系膜小动脉作形态学测量。结果 :高盐与正常盐饲养组间 ,大鼠体重在分组前后均无区别。高盐饲料饲养后第 8周起 ,高盐组鼠尾血压明显高于正常盐饲养组 ,并持续至实验结束 ,且随时间增加 ,血压增高更明显。颈动脉平均压测量结果进一步证实高盐饲养组血压明显高于正常盐饲养组。检测大、中、小血管的血管中层厚度、中层厚度与管腔比率、血管壁横截面积 ,高盐饲养组均明显较正常盐饲养组增大 ,但两组间血管腔径无区别。高盐饲养组左心室重量指数明显高于正常盐饲养组。结论 :长期高盐饲养可致正常Wistar大鼠血压升高。故单纯高盐饮食在正常生理状态下的Wistar大鼠可形成一种新的高血压模型 ,且高血压形成同时伴随有循环系统心脏和血管的重构现象。该高血压模型可能较盐敏感性高血压模型更接近人类的高盐摄入与高血压病的实际情况。

AIM : To establish a new salt hypertensive rat model and to investigate the effects of high salt diet on changes of blood pressure and arterial structural in normal Wistar rats. METHODS : 27 male Wistar rats were randomly divided into two groups after weaning (3 weeks): normal salt diet group and high salt diet group which were given normal ( 0.5 % NaCl) or high (4% NaCl) salt diet for 18 weeks. Tail cuff systolic blood pressure and body weight were examined. At the end of the treatment, arterial vessels were prepared by perfusion fixation. Vascular dimension in thoracic artery, renal artery and small mesenteric artery were measured. RESULTS : There was no significant difference in body weights between two groups before and after feeding. After eight weeks high salt diet treatment, tail cuff systolic blood pressure was significantly higher than that in normal salt diet group, and the difference became more significant in the following day. Direct measurement of mean blood pressure in right carotid artery at the end of the experiment confirmed the results obtained by the tail cuff method. The media thickness, media thickness to lumen diameter ratios and cross section area in aorta, renal artery and small mesenteric artery were significantly higher in high salt diet group than that in the normal salt diet group. But there was no significant difference in lumen diameters in any of the arteries among two groups. Heart weight index was significantly higher in high salt diet group than that in normal salt diet group. CONCLUSION : Long term high salt diet can induce hypertension in normal Wistar rats. The increased blood pressure is associated with the hypertrophy of heart and arteries in this new hypertension model. This model is similar to human hypertension induced by high salt diet.