Renal and cardiac sympathetic baroreflexes in hypertensive rabbits
Renal and cardiac sympathetic baroreflexes in hypertensive rabbits
复制标题
DOI：
10.1046/j.1440-1681.2001.03567.x
复制
发表时间：
2001-12-01
影响因子：
2.9
通讯作者：
Burke, SL
中科院分区：
文献类型：
--
作者：
Head, GA;Burke, SL
1.本研究的目的是评估清醒兔肾夹闭后高血压发展过程中肾交感神经活动(RSNA)压力反射的变化。2．在兔子的右肾动脉上安装夹子或在氟烷麻醉下进行假手术。实验前1周、初次手术后3或6周将记录电极植入左肾神经。在实验过程中，药物引起的平均动脉压 (MAP) 的上升和下降被用来产生 RSNA 和心率 (HR) 压力反射曲线。每个实验的RSNA 都根据刺激独立于压力感受器的三叉神经传入引起的最大RSNA 进行校准。3．夹子植入后 3 周和 6 周，平均动脉压分别升高 20% 和 36%。肾交感神经活动压力反射曲线相应向右重置，但RSNA曲线形状受到不同程度的影响。 4．在两个高血压期，由于曲率减小，MAP-HR 压力反射增益显着降低。 HR压力反射范围增加。 RSNA 压力反射增益在第 3 周时减少，这是由于 RSNA 压力反射范围降低了 35%，但在 6 周时与假手术动物相似。5。结果表明，在已建立的两肾一夹高血压家兔中，交感压力反射保存较好，但心脏压力反射的敏感性减弱。因此，RSNA压力反射的短期抑制与血压水平或继发性变化（例如心脏或血管肥大）的发生无关，但可能与循环血管紧张素有关，已知此时血管紧张素会增加。
1. The purpose of the present study was to assess the changes to renal sympathetic nerve activity (RSNA) baroreflexes during the development of hypertension after renal clipping in conscious rabbits.2. Rabbits were fitted with a clip on the right renal artery or underwent a sham operation under halothane anaesthesia. A recording electrode was implanted on the left renal nerve 1 week before the experiment, 3 or 6 weeks after the initial operation. During the experiment, drug-induced ramp rises and falls in mean arterial pressure (MAP) were used to produce RSNA and heart rate (HR) baroreflex curves. The RSNA for each experiment was calibrated against maximum RSNA evoked by stimulation of baroreceptor-independent trigeminal afferents.3. Mean arterial pressure was 20 and 36% higher 3 and 6 weeks after clip implantation, respectively. Renal sympathetic nerve activity baroreflex curves were reset rightwards accordingly, but the shape of the RSNA curves was differentially affected.4. At both hypertensive periods, MAP-HR baroreflex gain was markedly reduced due to a reduction in curvature. The HR baroreflex range was increased. The RSNA baroreflex gain was reduced at 3 weeks, which was due to a 35% lower RSNA baroreflex range, but was similar to sham animals at 6 weeks.5. The results show that, in established two kidney, one clip hypertension in rabbits, the sympathetic baroreflex is relatively well preserved but sensitivity of cardiac baroreflexes is attenuated. Therefore, the short-term inhibition of RSNA baroreflexes is not related to the level of blood pressure or the development of secondary changes, such as cardiac or vascular hypertrophy, but may be related to circulating angiotensin, which is known to increase at this time.