Becker Bryan K, Feagans Amanda C, Chen Daian, Kasztan Malgorzata, Jin Chunhua, Speed Joshua S, Pollock Jennifer S, Pollock David M
Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama.
Cardio-Renal Physiology and Medicine, Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
Am J Physiol Regul Integr Comp Physiol. 2017 Oct 1;313(4):R425-R437. doi: 10.1152/ajpregu.00174.2017. Epub 2017 Jul 12.
Hypertension is a prevalent pathology that increases risk for numerous cardiovascular diseases. Because the etiology of hypertension varies across patients, specific and effective therapeutic approaches are needed. The role of renal sympathetic nerves is established in numerous forms of hypertension, but their contribution to salt sensitivity and interaction with factors such as endothelin-1 are poorly understood. Rats deficient of functional ET receptors (ET-def) on all tissues except sympathetic nerves are hypertensive and exhibit salt-sensitive increases in blood pressure. We hypothesized that renal sympathetic nerves contribute to hypertension and salt sensitivity in ET-def rats. The hypothesis was tested through bilateral renal sympathetic nerve denervation and measuring blood pressure during normal salt (0.49% NaCl) and high-salt (4.0% NaCl) diets. Denervation reduced mean arterial pressure in ET-def rats compared with sham-operated controls by 12 ± 3 (SE) mmHg; however, denervation did not affect the increase in blood pressure after 2 wk of high-salt diet (+19 ± 3 vs. +16 ± 3 mmHg relative to normal salt diet; denervated vs. sham, respectively). Denervation reduced cardiac sympathetic-to-parasympathetic tone [low frequency-high frequency (LF/HF)] during normal salt diet and vasomotor LF/HF tone during high-salt diet in ET-def rats. We conclude that the renal sympathetic nerves contribute to the hypertension but not to salt sensitivity of ET-def rats.
高血压是一种常见的病理状态,会增加多种心血管疾病的风险。由于高血压的病因因患者而异,因此需要特定且有效的治疗方法。肾交感神经在多种形式的高血压中所起的作用已得到证实,但其对盐敏感性的影响以及与内皮素-1等因素的相互作用却知之甚少。除交感神经外,所有组织均缺乏功能性内皮素受体(ET缺陷)的大鼠患有高血压,且血压对盐敏感。我们假设肾交感神经在ET缺陷大鼠的高血压和盐敏感性中起作用。通过双侧肾交感神经去神经支配并在正常盐(0.49%氯化钠)和高盐(4.0%氯化钠)饮食期间测量血压来验证这一假设。与假手术对照组相比,去神经支配使ET缺陷大鼠的平均动脉压降低了12±3(标准误)mmHg;然而,去神经支配并未影响高盐饮食2周后血压的升高(相对于正常盐饮食分别为+19±3与+16±3 mmHg;去神经支配组与假手术组)。去神经支配降低了ET缺陷大鼠在正常盐饮食期间的心脏交感神经与副交感神经张力[低频-高频(LF/HF)]以及在高盐饮食期间的血管运动LF/HF张力。我们得出结论,肾交感神经在ET缺陷大鼠的高血压中起作用,但在盐敏感性方面不起作用。