Perivascular radiofrequency renal denervation lowers blood pressure and ameliorates cardiorenal fibrosis in spontaneously hypertensive rats

Figures

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  Fig 1. Radiofrequency-mediated perivascular renal denervation in rats. (A) a representative procedure photo. Red arrow, renal artery; black arrow, ablation catheter. (B-F) Hematoxylin & eosin-stained sections of WKY rat renal arteries after perivascular ablation with the radiofrequency power of 0- (B), 1- (C), 2- (D), 3- (E), and 4-watt (F) show that renal nerve bundles were disrupted by radiofrequency ablation with 2-, 3-, or 4-watt and that renal arteries got damaged and thinned after ablation with 3 or 4 watts. Black arrows, perivascular nerves; red arrows, damaged renal artery. Scale bar, 200 μm.

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  Fig 2. Blood pressure and heart rate after perivascular renal denervation. The systolic (A) and diastolic (B) blood pressure (BP) and heart rate (C) of spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats the day before radiofrequency ablation (RFA) or phenol-ethanol ablation (PEA) and on day 14 and 28 after the procedure. Data are mean ± SE (n = 10 in sham group and RFA group, n = 6 in PEA group at each time point) **P<0.01 vs. the same rat strain in sham group at the same time point. #P<0.05 vs. SHR in PEA group at the same time point. bpm, beat per minute.

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  Fig 3. Perivascular radiofrequency ablation destroys renal nerves. Hematoxylin & eosin-stained (A) and immunohistochemistry (anti-tyrosine hydroxylase (TH) antibody)-stained (B) sections of rat renal arteries of spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats sacrificed on day 14 after radiofrequency ablation (RFA) and on day 28 after sham procedure or RFA show that the renal nerve bundles were disrupted and the TH expression was diminished in RFA group compared to sham group. Arrows indicate perivascular nerves. (C) The percentage of TH-positive area in the entire sympathetic nerve area. Data are mean ± SE from 10 rats in each group at each time point. **P<0.01 vs. sham groups.

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  Fig 4. Perivascular radiofrequency ablation decreases plasma catecholamines. The plasma dopamine (A), epinephrine (B), and norepinephrine (C) of spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats the day before radiofrequency ablation (RFA) and day 14 and day 28 after the ablation. Data are mean ± SE from 10 rats in each group at each time point. **P<0.01 vs. sham groups.

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  Fig 5. Perivascular ablation attenuates cardiorenal fibrosis. Masson trichrome-stained sections of heart (A) and kidney (B) of spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats sacrificed on day 28 following sham procedure, radiofrequency ablation (RFA), or phenol-ethanol ablation (PEA). The quantification of fibrous area in heart (C) and kidney (D). Data are mean ± SE (n = 10 for sham and RFA groups and n = 6 for PEA group). **P<0.01 vs. sham groups.

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  Fig 6. Renal artery after perivascular ablation. Movat pentachrome-stained sections of renal arteries of spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats sacrificed on day 28 following sham procedure, radiofrequency ablation (RFA), or phenol-ethanol ablation (PEA).

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  Fig 7. Renal function and urinary excretions after perivascular ablation. The serum creatinine (A), blood urea nitrogen (BUN) (B), and urinary excretions of potassium (C), sodium (D), chloride (E), and protein (F) of spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats at 28 days after sham procedure, radiofrequency ablation (RFA), or phenol-ethanol ablation (PEA). Data are mean ± SE (n = 10 for sham and RFA groups and n = 6 for PEA group). **P<0.01 vs. sham group.