Acute renal denervation normalizes aortic function and decreases blood pressure in spontaneously hypertensive rats

Figure 1. Blood pressure 4 days after intervention. (a) Systolic blood pressure (SBP); (b) diastolic blood pressure (DBP); (c) mean blood pressure (MBP). Data were analyzed by two-way ANOVA followed by Tukey’s post hoc test. Values are mean ± SEM. ANOVA: Interaction factor (I); Blood pressure background factor (P); Denervation factor (D). **p < 0.01; ***p < 0.001 vs. hypertensive sham (HS).

Figure 2. Autonomic balance 4 days after intervention. (a) Heart rate (HR); (b) heart rate variance (HRVar); (c) square root of the sum of the squares of the consecutive pulse interval differences (RMSSD); (d) high frequency (HF) modulation; (e) low frequency (LF) modulation. (f) Alpha index (AI). Data were analyzed by two-way ANOVA followed by Tukey’s post hoc test. Values are mean ± SEM. ANOVA: Interaction factor (I); Blood pressure background factor (P); Denervation factor (D). *p < 0.05; **p < 0.01; ****p < 0.0001 vs. hypertensive sham (HS).

Figure 3. Metabolic parameters 72 h after intervention. (a) Water intake; (b) urinary volume; (c) hydric balance. Data were analyzed by two-way ANOVA followed by Tukey’s post hoc test. Values are mean ± SEM. ANOVA: interaction factor (I); blood pressure background factor (P); denervation factor (D). *p < 0.05; **p < 0.01 vs. hypertensive sham.

Figure 4. Aorta relaxation 7–10 days after renal denervation. (a) Concentration–response curve to sodium nitroprusside; (b) Concentration–response curve to Acetylcholine. NS: normotensive sham (n = 6); ND: denervated normotensive (n = 9), HS: SHR sham (n = 5); HD: denervated SHR (n = 4). Data were analyzed by two-way ANOVA followed by Fisher post hoc test. Values are mean ± SEM. ANOVA: Interaction factor (I); Concentration factor (C); Groups factor (G); Matching (M). #p < 0.05; ##p < 0.01; ####p < 0.0001 NS vs. ND; *p < 0.05 HS vs. HD.

Figure 5. Concentration–response curve to phenylephrine. NS: normotensive sham (n = 6); ND: denervated normotensive (n = 9), HS: SHR sham (n = 5); HD: denervated SHR (n = 4). Data were analyzed by two-way ANOVA followed by Fisher post hoc test. Values are mean ± SEM. ANOVA: Interaction factor (I); Concentration factor (C); Groups factor (G); Matching (M). ####p < 0.0001 NS vs. ND; *p < 0.05; ***p < 0.001 HS vs. HD.

Figure 6. Representative images obtained from picrosirius-stained transverse aortic tissue sections from normotensive rats submitted to sham surgery (NS) or to renal denervation (ND), sham-operated spontaneous hypertensive rats (HS) or spontaneous hypertensive rats undergoing renal denervation (HD). Picrosirius staining demonstrates collagen in red and shows the typical histological organization of a normal aorta in all sections. The tunica media (blue lines) shows thin collagenous fibers interspersed among organized layers of smooth muscle cells and elastic lamellae (arrowheads). The tunica adventitia (asterisks) typically display coarse collagen fibers. Note that there is no difference between the groups for aorta morphology. Scale bars represent 50 µm.

Figure 7. Schematic timeline protocol. RDN = renal denervation; h = hours.