Angiotensin II acts at AT1 receptors in the nucleus of the solitary tract to attenuate the baroreceptor reflex
Angiotensin II acts at AT1 receptors in the nucleus of the solitary tract to attenuate the baroreceptor reflex
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DOI：
10.1152/ajpregu.1998.275.5.r1611
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发表时间：
1998-11-01
影响因子：
2.8
通讯作者：
Ferrario, CM
中科院分区：
文献类型：
--
作者：
Matsumura, K;Averill, DB;Ferrario, CM
本研究的目的是确定ANG II：是否作用于孤束核（NTS）中的1型（AT（1））或2型（AT（2））受体，以减少肾交感神经活动（RSNA）和心率（HR）的压力感受器反射控制。实验在麻醉的Wistar-Kyoto（WKY）和自发性高血压大鼠（SKR）中进行。在NTS中双侧微量注射CV-11974（AT 1受体拮抗剂，10 pmol）、PD-123319（AT（2）受体拮抗剂，100 pmol）或人工脑脊液（aCSF，50 nl）之前和之后，通过静脉输注苯肾上腺素或硝普钠引起RSNA和HR的反射变化。平均动脉压（MAP）-RSNA和MAP-MR数据拟合Logistic函数分析压力感受性反射。与WKY大鼠相比，SHR对RSNA和MR的压力感受器反射敏感性减弱。在任一品系的NTS中双侧注射CV-11974、PD-123319或aCSF对基线动脉压、HR或RSNA均无影响。孤束核注射CV-11974可显著增加SHR和WKY大鼠RSNA和MR的压力感受性反射控制敏感性（P < 0.01）。PD-123319和aCSF均未改变SHR或WKY大鼠RSNA和HR的压力感受性反射控制。这些结果表明，内源性ANG II作用于NTS的ATI受体，减弱SHR和WKY大鼠的压力感受性反射。
The object of the current study was to determine if ANG II: acts at type 1 (AT(1)) or type 2 (AT(2)) receptors in the nucleus of the solitary tract (NTS) to reduce baroreceptor reflex control of renal sympathetic nerve activity (RSNA) and heart rate (HR). Experiments were carried out in urethan-anesthetized Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SKR). Reflex changes in RSNA and HR were elicited by intravenous infusion of either phenylephrine or sodium nitroprusside before and after bilateral microinjection of CV-11974 (AT1 receptor antagonist, 10 pmol), PD-123319 (AT(2) receptor antagonist, 100 pmol), or artificial cerebrospinal fluid (aCSF, 50 nl) in the NTS. Mean arterial pressure (MAP)-RSNA and MAP-MR data were fit to logistic functions to analyze the baroreceptor reflex. Baroreceptor reflex sensitivities for RSNA and MR were attenuated in SHR compared with those in WKY rats. Bilateral injection of CV-11974, PD-123319, or aCSF in the NTS of either strain had no effect on baseline arterial pressure, HR, or RSNA. However, CV-11974 injected in the NTS increased significantly (P < 0.01) the sensitivities for baroreceptor reflex control of RSNA and MR in SHR and WKY rats. Neither PD-123319 nor aCSF altered baroreceptor reflex control of RSNA and HR in either SHR or WKY rats. These results demonstrate that endogenous ANG Il acts at ATI receptors of the NTS to attenuate the baroreceptor reflex in SHR as well as in WKY rats.