This work was supported by the National Natural Science Foundation of China (81770420), Science and Technology Commission of Shanghai Municipality (20140900600), Shanghai Key Laboratory of Clinical Geriatric Medicine (13dz2260700), Shanghai Municipal Key Clinical Specialty (shslczdzk02801) and Center of geriatric coronary artery disease, Huadong Hospital Affiliated to Fudan University.

All animal experimental procedures complied with the relevant ethical Guide for the Care and Use of Laboratory Animals (NIH Publication no. 85-23, revised 2011) and were approved by the committees on animal research of Huadong Hospital affiliated to Fudan University. Fourteen-week-old male C57BL/6 mice (28-30g) were randomly divided into four groups: Sham group, Sham+Ang II group, RDN group, RDN+Ang II group, n = 6 in each group. All animals were maintained under specific closed pathogen-free conditions in a temperature-...

<ol>
	<li>Messerli, F. H., Rimoldi, S. F., Bangalore, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+transition+from+hypertension+to+heart+failure:+Contemporary+update.">The transition from hypertension to heart failure: Contemporary update.</a> JACC Heart Failure. 5 (8), 543-551 (2017).</li><li>Lackland, D. T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Implications+of+recent+clinical+trials+and+hypertension+guidelines+on+stroke+and+future+cerebrovascular+research.">Implications of recent clinical trials and hypertension guidelines on stroke and future cerebrovascular research.</a> Stroke. 49 (3), 772-779 (2018).</li><li>Rossignol, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+double+challenge+of+resistant+hypertension+and+chronic+kidney+disease.">The double challenge of resistant hypertension and chronic kidney disease.</a> The Lancet. 386 (10003), 1588-1598 (2015).</li><li>Du, X., Patel, A., Anderson, C. S., Dong, J., Ma, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Epidemiology+of+cardiovascular+disease+in+China+and+opportunities+for+improvement.">Epidemiology of cardiovascular disease in China and opportunities for improvement.</a> JACC International. Journal of the American College of Cardiology. 73 (24), 3135-3147 (2019).</li><li>Valenzuela, P. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lifestyle+interventions+for+the+prevention+and+treatment+of+hypertension.">Lifestyle interventions for the prevention and treatment of hypertension.</a> Nature Review Cardiology. 18 (4), 251-275 (2021).</li><li>Krum, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Catheter-based+renal+sympathetic+denervation+for+resistant+hypertension:+a+multicentre+safety+and+proof-of-principle+cohort+study.">Catheter-based renal sympathetic denervation for resistant hypertension: a multicentre safety and proof-of-principle cohort study.</a> The Lancet. 373 (9671), 1275-1281 (2009).</li><li>Bhatt, D. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+controlled+trial+of+renal+denervation+for+resistant+hypertension.">A controlled trial of renal denervation for resistant hypertension.</a> The New England Journal of Medicine. 370 (15), 1393-1401 (2014).</li><li>Kjeldsen, S. E., Narkiewicz, K., Burnier, M., Oparil, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Renal+denervation+achieved+by+endovascular+delivery+of+ultrasound+in+RADIANCE-HTN+SOLO+or+by+radiofrequency+energy+in+SPYRAL+HTN-OFF+and+SPYRAL-ON+lowers+blood+pressure.">Renal denervation achieved by endovascular delivery of ultrasound in RADIANCE-HTN SOLO or by radiofrequency energy in SPYRAL HTN-OFF and SPYRAL-ON lowers blood pressure.</a> Blood Press. 27 (4), 185-187 (2018).</li><li>B&#246;hm, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficacy+of+catheter-based+renal+denervation+in+the+absence+of+antihypertensive+medications+(SPYRAL+HTN-OFF+MED+Pivotal):+a+multicentre,+randomised,+sham-controlled+trial.">Efficacy of catheter-based renal denervation in the absence of antihypertensive medications (SPYRAL HTN-OFF MED Pivotal): a multicentre, randomised, sham-controlled trial.</a> The Lancet. 395 (10234), 1444-1451 (2020).</li><li>Azizi, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endovascular+ultrasound+renal+denervation+to+treat+hypertension+(RADIANCE-HTN+SOLO):+a+multicentre,+international,+single-blind,+randomised,+sham-controlled+trial.">Endovascular ultrasound renal denervation to treat hypertension (RADIANCE-HTN SOLO): a multicentre, international, single-blind, randomised, sham-controlled trial.</a> The Lancet. 391 (10137), 2335-2345 (2018).</li><li>Kandzari, D. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+renal+denervation+on+blood+pressure+in+the+presence+of+antihypertensive+drugs:+6-month+efficacy+and+safety+results+from+the+SPYRAL+HTN-ON+MED+proof-of-concept+randomised+trial.">Effect of renal denervation on blood pressure in the presence of antihypertensive drugs: 6-month efficacy and safety results from the SPYRAL HTN-ON MED proof-of-concept randomised trial.</a> The Lancet. 391 (10137), 2346-2355 (2018).</li><li>Townsend, R. R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Catheter-based+renal+denervation+in+patients+with+uncontrolled+hypertension+in+the+absence+of+antihypertensive+medications+(SPYRAL+HTN-OFF+MED):+a+randomised,+sham-controlled,+proof-of-concept+trial.">Catheter-based renal denervation in patients with uncontrolled hypertension in the absence of antihypertensive medications (SPYRAL HTN-OFF MED): a randomised, sham-controlled, proof-of-concept trial.</a> The Lancet. 390 (10108), 2160-2170 (2017).</li><li>Sun, X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Renal+denervation+restrains+the+inflammatory+response+in+myocardial+ischemia-reperfusion+injury.">Renal denervation restrains the inflammatory response in myocardial ischemia-reperfusion injury.</a> Basic Research in Cardiology. 115 (2), 15 (2020).</li><li>Sharp, T. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Renal+denervation+prevents+heart+failure+progression+via+inhibition+of+the+renin-angiotensin+system.">Renal denervation prevents heart failure progression via inhibition of the renin-angiotensin system.</a> Journal of the American College of Cardiology. 72 (21), 2609-2621 (2018).</li><li>Wang, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Renal+denervation+attenuates+progression+of+atherosclerosis+in+apolipoprotein+E-deficient+mice+independent+of+blood+pressure+lowering.">Renal denervation attenuates progression of atherosclerosis in apolipoprotein E-deficient mice independent of blood pressure lowering.</a> Hypertension. 65 (4), 758-765 (2015).</li><li>Chen, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Renal+denervation+mitigates+atherosclerosis+in+ApoE-/-+mice+via+the+suppression+of+inflammation.">Renal denervation mitigates atherosclerosis in ApoE-/- mice via the suppression of inflammation.</a> American Journal of Translational Research. 12 (9), 5362-5380 (2020).</li><li>Wang, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Renal+denervation+promotes+atherosclerosis+in+hypertensive+apolipoprotein+E-deficient+mice+infused+with+Angiotensin+II.">Renal denervation promotes atherosclerosis in hypertensive apolipoprotein E-deficient mice infused with Angiotensin II.</a> Frontiers in Physiology. 8, 215 (2017).</li><li>Eriguchi, M., Tsuruya, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Renal+sympathetic+denervation+in+rats.">Renal sympathetic denervation in rats.</a> Methods in Molecular Biology. 1397, 45-52 (2016).</li><li>Thukkani, A. K., Bhatt, D. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Renal+denervation+therapy+for+hypertension.">Renal denervation therapy for hypertension.</a> Circulation. 128 (20), 2251-2254 (2013).</li><li>Zhang, Y. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=NAD(+)+administration+decreases+microvascular+damage+following+cardiac+ischemia/reperfusion+by+restoring+autophagic+flux.">NAD(+) administration decreases microvascular damage following cardiac ischemia/reperfusion by restoring autophagic flux.</a> Basic Research in Cardiology. 115 (5), 57 (2020).</li><li>Wang, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Long-term+renal+sympathetic+denervation+ameliorates+renal+fibrosis+and+delays+the+onset+of+hypertension+in+spontaneously+hypertensive+rats.">Long-term renal sympathetic denervation ameliorates renal fibrosis and delays the onset of hypertension in spontaneously hypertensive rats.</a> American Journal of Translational Research. 10 (12), 4042-4053 (2018).</li><li>Lu, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Subcutaneous+Angiotensin+II+infusion+using+osmotic+pumps+induces+aortic+aneurysms+in+mice.">Subcutaneous Angiotensin II infusion using osmotic pumps induces aortic aneurysms in mice.</a> Journal of Visualized Experiments: JoVE. (103), e53191 (2015).</li><li>Wilde, E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tail-cuff+technique+and+its+influence+on+central+blood+pressure+in+the+mouse.">Tail-cuff technique and its influence on central blood pressure in the mouse.</a> Journal of the American Heart Association. 6 (6), 005204 (2017).</li><li>Daugherty, A., Rateri, D., Hong, L., Balakrishnan, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measuring+blood+pressure+in+mice+using+volume+pressure+recording,+a+tail-cuff+method.">Measuring blood pressure in mice using volume pressure recording, a tail-cuff method.</a> Journal of Visualized Experiments: JoVE. (27), e1291 (2009).</li><li>Esler, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Illusions+of+truths+in+the+Symplicity+HTN-3+trial:+generic+design+strengths+but+neuroscience+failings.">Illusions of truths in the Symplicity HTN-3 trial: generic design strengths but neuroscience failings.</a> Journal of the American Society of Hypertension. 8 (8), 593-598 (2014).</li><li>Han, W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Low-dose+sustained-release+deoxycorticosterone+acetate-induced+hypertension+in+Bama+miniature+pigs+for+renal+sympathetic+nerve+denervation.">Low-dose sustained-release deoxycorticosterone acetate-induced hypertension in Bama miniature pigs for renal sympathetic nerve denervation.</a> Journal of the American Society of Hypertension. 11 (5), 314-320 (2017).</li><li>Han, W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+safety+of+renal+denervation+as+assessed+by+optical+coherence+tomography:+pre-+and+post-procedure+comparison+with+multi-electrode+ablation+catheter+in+animal+experiment.">The safety of renal denervation as assessed by optical coherence tomography: pre- and post-procedure comparison with multi-electrode ablation catheter in animal experiment.</a> Hellenic Journal of Cardiology. 61 (3), 190-196 (2020).</li><li>Cai, X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Noninvasive+stereotactic+radiotherapy+for+renal+denervation+in+a+swine+model.">Noninvasive stereotactic radiotherapy for renal denervation in a swine model.</a> Journal of the American College of Cardiology. 74 (13), 1697-1709 (2019).</li></ol>

There are no conflicts of interest, financial or otherwise, as declared by the authors.

Whether RDN could lower blood pressure has become controversial since the publication of the negative result of the symplicity HTN-3 trial7,25. However, the several clinical trials and animal experiments have demonstrated positive and effective results of RDN on hypertensive humans and animals9,10,11,12,13</...

Hypertension is a major chronic cardiovascular disease around the world. Uncontrolled hypertension could damage target organs and contribute to heart failure, stroke, and chronic kidney diseases1,2,3. The prevalence of hypertension has increased from 20% to 31% between 1991 and 2007 in China. The number of adults with hypertension in China could double following a recent revision of the diagnostic criteria for hypertension (130/80 mmHg)4. Hypertension can be controlled by medicine, however, approximately 20% of patients are unable to control their hypertension, even when receiving at least three antihypertensive drugs (including one diuretic) at maximally tolerated dose, which may lead to the development of drug-resistant hypertension5.
Renal sympathetic denervation (RDN) has been proven to be a potential treatment for hypertension. In 2009, Krum and colleagues reported resistant hypertension treatment using RDN for the first time. It was found that percutaneous renal artery ablation can effectively cause persistent blood pressure reduction in patients6. However, the failure of the Symplicity Hypertension 3 (HTN-3) trial impeded the application of RDN7, turning RDN into a controversial therapy. Nevertheless, the prospect of RDN have not yet been ruled out. Recent clinical trials, including RADIANCE-HTN SOLO, SPYRAL HTN-OFF MED/ON MED, and SPYRAL HTN-OFF MED Pivotal have confirmed the efficacy of RDN on hypertension8,9,10,11,12. Thus, more detailed mechanistic research needs to be performed to explore the effects of RDN.
The overall purpose of this study is to demonstrate how RDN in mice can be modified to produce a simpler and more stable surgery. A large number of experiments have studied various approaches of RDN, such as intravascular cryoablation, extracorporeal ultrasound and local application of a chemical or neurotoxin in different animal models13,14,15,16,17. The RDN model generated using chemical ablation with phenol is a well-established experimental model to study the pathogenesis of sympathetic activation on hypertension. This model is generated by chemical corrosion of the renal sympathetic nerves with 10% phenol/ethanol solution using a cotton swab18. On one hand, the conventional RDN potentially inhibit renal sympathetic activity, which then decreases renin secretion and sodium reabsorption, and increases renal blood flow. On the other hand, it suppresses renin-angiotensin-aldosterone system19. Thereby, RDN has a beneficial effect on hypertension. However, the chemical ablation generated RDN model lacks ablation criteria and ablation time and the details of the experimental procedure are yet unclear. Also, there are no technical reports available. In this report, we describe a surgical protocol for the generation of RDN model with phenol using weigh paper in Angiotensin II (Ang II) induced hypertension in C57BL/6 mice. We wrap the renal artery with weighing paper containing phenol and unify the ablation time, which helps to establish a more reproducible, reliable RDN model. This experimental model is aimed to evaluate the effect of RDN on hypertension.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Angiotensin II</td>
			<td>Sangon Biotech</td>
			<td>CAS:4474-91-3</td>
			<td>To make a hypertensive animol model</td>
		</tr>
		<tr>
			<td>Anti-Tyrosine Hydroxylase antibody</td>
			<td>Abcam</td>
			<td>ab137869</td>
			<td>To evaluate the expression of TH of renal nerves</td>
		</tr>
		<tr>
			<td>Blood Pressure Analysis</td>
			<td>Visitech Systems</td>
			<td>BP-2000</td>
			<td>Measure the blood pressure of mice</td>
		</tr>
		<tr>
			<td>Mini-osmotic pump</td>
			<td>DURECT Corporation</td>
			<td>CA 95014</td>
			<td>To fill with Angiotensin II</td>
		</tr>
		<tr>
			<td>Norepinephrine ELISA Kit</td>
			<td>Abcam</td>
			<td>ab287789</td>
			<td>to measure renal norepinephrine levels</td>
		</tr>
		<tr>
			<td>Phenol</td>
			<td>Sangon Biotech</td>
			<td>CAS:108-95-2</td>
			<td>Damage the renal sympathetic nerve</td>
		</tr>
		<tr>
			<td>Weighing paper</td>
			<td>Sangon Biotech</td>
			<td>F512112</td>
			<td>To destroy renal nerve with weighing paper immersed with phenol; https://www.sangon.com/productDetail?productInfo.code=F512112.&#160;</td>
		</tr>
	</tbody>
</table>

improved renal denervation mitigated hypertension induced by angiotensin ii infusion

The benefits of renal sympathetic denervation (RDN) on blood pressure have been proved in a large number of clinical trials in recent years. However, the regulatory mechanism of RDN on hypertension remains elusive. Thus, it&#39;s essential to establish a simpler RDN model in mice. In this study, osmotic mini pumps filled with Angiotensin II were implanted in 14-week-old C57BL/6 mice. One week after the implantation of the mini-osmotic pump, a modified RDN procedure was performed on bilateral renal arteries of the mice using phenol. Age-sex-matched mice were given saline and served as sham group. Blood pressure was measured at baseline and every week subsequently for 21 days. Then, renal artery, abdominal aorta and heart were collected for histological examination using H&#38;E and Masson staining. In this study, we present a simple, practical, repeatable, and standardized RDN model, which can control hypertension and alleviate cardiac hypertrophy. The technique can denervate peripheral renal sympathetic nerves without renal artery damage. Compared to previous models, the modified RDN facilitates the study of the pathobiology and pathophysiology of hypertension.

Statistics 
All data are expressed as mean &#177; standard deviation. One-way ANOVA was used for experiments with three or more conditions followed by Bonferroni posthoc tests for comparisons between individual groups. Consider a p-value equal or less than 0.05 as significant. A commercial software was used to perform all statistical analysis.
Increase in blood pressure induced by Ang II was attenuated after RDN 
Significant increase in systolic BP (...

Watch this Scientific Journal Video about Improved Renal Denervation Mitigated Hypertension Induced by Angiotensin II Infusion at JoVE.com

Improved Renal Denervation Mitigated Hypertension Induced by Angiotensin II Infusion

Here, we present a protocol for renal sympathetic denervation (RDN) in mice with hypertension induced by Angiotensin II infusion. The procedure is repeatable, convenient and allows to study the regulatory mechanisms of RDN on hypertension and cardiac hypertrophy.

The benefits of renal sympathetic denervation (RDN) on blood pressure have been proved in a large number of clinical trials in recent years. However, the ...

improved-renal-denervation-mitigated-hypertension-induced-angiotensin

Research

Education

JoVE Journal

JoVE Core

Anatomy and Physiology

Pharmacology

Medicine

Unit 1

Blood Vessels and Circulation

Cardiovascular Drugs: Antihypertensive Drugs

SCIENTISTS IN ACTION

2.8K Views.  Huadong Hospital Affiliated to Fudan University. Here, we present a protocol for renal sympathetic denervation (RDN) in mice with hypertension induced by Angiotensin II infusion. The procedure is repeatable, convenient and allows to study the regulatory mechanisms of RDN on hypertension and cardiac hypertrophy.