Renal sympathetic denervation attenuates hypertension and vascular remodeling in renovascular hypertensive rats

Circulating interleukins concentrations and post-stroke depression: A systematic review and meta-analysis

Interleukins may play a role in supporting the diagnosis of post-stroke depression (PSD). Here, eight databases were employed to search for studies on circulating interleukins concentrations in patients with PSD. A total of 45 studies exploring circulating interleukins in PSD and stroke patients without depression (NPSD) were included in the retrieval database, including IL-1(5), IL-1β (10), IL-2(6), IL-6(35), IL-10(7), IL-17(5), IL-18(6). Then, the RevMan 5.4 software was used for meta-analysis. The results of the meta-analysis showed that the PSD patients have higher concentrations of IL-1, IL-4, IL-6, and lower concentrations of IL-10 than NPSD patients. Additionally, the circulating IL-1, IL-6, and IL-18 concentrations in PSD patients were significantly higher than those in NPSD patients in the acute phase; the circulating IL-6 and IL-17 concentrations in PSD patients were significantly higher than those in NPSD patients at discharge; the PSD patients have lower concentrations sin IL-2 but higher concentrations in IL-6 and IL-17 than NPSD patients at the 3rd and 6th month. Our research provides evidence that circulating interleukins may have clinical utility as a biomarker for identifying PSD.

Renal denervation restores biomechanics of carotid arteries in a rat model of hypertension

The prevalence of hypertension increases with aging and is associated with increased arterial stiffness. Resistant hypertension is presented when drug treatments fail to regulate a sustained increased blood pressure. Given that the mechanisms between the sympathetic nervous system and the kidney play an important role in blood regulation, renal denervation (RDN) has emerged as a therapeutic potential in resistant hypertension. In this study, we investigated the effects of RDN on the biomechanical response and microstructure of elastic arteries. Common carotid arteries (CCA) excised from 3-month, 8-month, and 8-month denervated rats were subjected to biaxial extension-inflation test. Our results showed that hypertension developed in the 8-month-old rats. The sustained elevated blood pressure resulted in arterial remodeling which was manifested as a significant stress increase in both axial and circumferential directions after 8 months. RDN had a favorable impact on CCAs with a restoration of stresses in values similar to control arteries at 3 months. After biomechanical testing, arteries were imaged under a multi-photon microscope to identify microstructural changes in extracellular matrix (ECM). Quantification of multi-photon images showed no significant alterations of the main ECM components, elastic and collagen fibers, indicating that arteries remained intact after RDN. Regardless of the experimental group, our microstructural analysis of the multi-photon images revealed that reorientation of the collagen fibers might be the main microstructural mechanism taking place during pressurization with their straightening happening during axial stretching.

Renal denervation restores biomechanics of carotid arteries in a rat model of hypertension

The prevalence of hypertension increases with aging and is associated with increased arterial stiffness. Resistant hypertension is presented when drug treatments fail to regulate a sustained increased blood pressure. Given that the mechanisms between the sympathetic nervous system and the kidney play an important role in blood regulation, renal denervation (RDN) has emerged as a therapeutic potential in resistant hypertension. In this study, we investigated the effects of RDN on the biomechanical response and microstructure of elastic arteries. Common carotid arteries (CCA) were excised from 3-, 8- and 8-month-old denervated rats, and subjected to biaxial extension-inflation test. Our results showed that hypertension developed in the 8-month-old rats. The sustained elevated blood pressure resulted in arterial remodeling which was manifested as a significant stress increase in both axial and circumferential directions after 8 months. RDN had a favorable impact on CCAs with a restoration of stresses in values similar to control arteries at 3 months. After biomechanical testing, arteries were imaged under a multi-photon microscope to identify microstructural changes in extracellular matrix (ECM). Quantification of multi-photon images showed no significant alterations of the main ECM components, elastic and collagen fibers, indicating that arteries remained intact after RDN. Regardless of the experimental group, our microstructural analysis of the multi-photon images revealed that reorientation of the collagen fibers might be the main microstructural mechanism taking place during pressurization with their straightening happening during axial stretching.

Proposed mechanisms of hypertension and risk of adverse cardiovascular outcomes in LGBT communities

Hypertension (HTN), a highly prevalent public issue affecting one in two adults in the United States, has recently been shown to differentially burden individuals belonging to marginalized communities, such as the lesbian, gay, bisexual, and transgender (LGBT) communities. The minority stress theory posits that a unique combination of marginalization-related psychosocial stressors and coping behaviors may underlie the increased burden of diseases like HTN in LGBT populations. Uncontrolled or poorly managed HTN often leads to the development of adverse cardiovascular outcomes, such as heart failure (HF). Despite our understanding of minority stress theory and demonstrated associations between LGBT identities and HTN, the mechanisms whereby psychosocial stress drives HTN in LGBT populations remain unclear. This mini-review discusses the physiological systems governing blood pressure and the epidemiology of HTN across different subgroups of LGBT people. In addition, we propose mechanisms demonstrated in the general population whereby psychological stress has been implicated in elevating blood pressure that may be occurring in LGBT populations. Finally, we discuss the limitations of current studies and methodological frameworks to make suggestions for study designs to better delineate the mechanisms of psychosocial stress-related HTN in LGBT communities.

Involvement of Neuropeptide Y within Paraventricular Nucleus in Electroacupuncture Inhibiting Sympathetic Activities in Hypertensive Rats

Although electroacupuncture (EA) has been used to decrease the blood pressure (BP) clinically, the underlying mechanisms are not clearly clarified. This study aimed to assess the hypothesis that EA treatment exerts a hypotensive action via suppressing sympathetic activities and modulating neuropeptide Y (NPY) function within the paraventricular nucleus (PVN) of hypertensive rats. Male Sprague-Dawley rats were selected for the experiment, and the hypertensive models were established by the two-kidney, one-clip (2K1C) method. Then, the rats were randomly assigned to the sham group, 2K1C group, 2K1C plus EA group, and 2K1C plus sham EA group. EA treatment at the acupoints ST36 and ST40 overlying the peroneal nerves was given once a day for 30 days. The radiotelemetry system was applied to collect the arterial BP recordings. Power spectral analyses of BP variability, BP responses to ganglionic blockade, and plasma levels of norepinephrine and epinephrine were performed to assess the changes in sympathetic nerve activity. Real-time PCR and Western blots were carried out to examine the expression of NPY system in the PVN. The responses of PVN microinjection with NPY Y1R antagonist BIBO3304 were detected to check the endogenous NPY tone. The results showed that the enhanced arterial BP and sympathetic activities were effectively reduced by 30 days of EA treatment, and baroreflex sensitivity was improved in 2K1C hypertensive rats. The level of NPY mRNA and protein expression in the PVN was markedly upregulated by EA treatment in 2K1C rats. In addition, the pressor responses of PVN microinjection with NPY Y1R antagonist BIBO3304 in 2K1C models were remarkably augmented by the EA stimulation. Our results indicate that the increased NPY expression and function in the PVN induced by EA treatment contribute to antihypertensive and sympathetic suppression on hypertensive rats. The findings may elucidate the underlying mechanisms of the acupuncture to be a potential therapeutic strategy against hypertension.

Renal sympathetic activation triggered by the rostral ventrolateral medulla is dependent of spinal cord AT1 receptors in Goldblatt hypertensive rats

Spinal cord neurons contribute to elevated sympathetic vasomotor activity in renovascular hypertension (2K1C), particularly, increased actions of angiotensin II. However, the origin of these spinal angiotensinergic inputs remains unclear. The present study aimed to investigate the role of spinal angiotensin II type 1 receptor (AT1) receptors in the sympathoexcitatory responses evoked by the activation of the rostral ventrolateral medulla (RVLM) in control and 2K1C Goldblatt rats. Hypertension was induced by clipping of the left renal artery. After 6 weeks, a catheter (PE-10) filled with losartan was inserted into the subarachnoid space and advanced to the T10-11 vertebral level in urethane-anesthetized rats. The effects of glutamate microinjection into the RVLM on blood pressure (BP), heart rate (HR), and renal and splanchnic sympathetic nerve activity (rSNA and sSNA, respectively) were evaluated in the presence or absence of spinal AT1 blockade. Tachycardic, pressor, and renal sympathoexcitatory effects caused by RVLM activation were significantly blunted by losartan in 2K1C rats, but not in control rats. However, no differences were found in the gene expression of angiotensin-converting enzyme, angiotensinogen, and renin in the spinal cord segments between the groups. In conclusion, acute sympathoexcitation induced by RVLM activation is dependent on the spinal AT1 receptor in Goldblatt, but not in control, rats. The involvement of other central cardiovascular nuclei in spinal angiotensinergic actions, as well as the source of angiotensin II, remains to be determined in the Goldblatt model.

Computed tomography-guided chemical renal sympathetic nerve modulation in the treatment of resistant hypertension: A case report

BACKGROUND

Resistant hypertension (RH) has always been a difficult problem in clinical diagnosis and treatment. At present, there is no recognized safe and effective minimally invasive treatment.

CASE SUMMARY

An 80-year-old woman was admitted to hospital due to trigeminal neuralgia (TN). The patient had a history of RH for more than 10 years and her blood pressure (BP) was not well-controlled. Before the treatment for TN, we decided to perform chemical renal sympathetic denervation with ethanol in the Pain Department of our hospital. One year after the operation, she stopped taking antihypertensive drugs, and her BP was satisfactorily controlled within 4 years after surgery.

CONCLUSION

Computed tomography-guided chemical renal sympathetic modulation may be a feasible method for the treatment of RH.

Responsiveness of afferent renal nerve units in renovascular hypertension in rats

Previous data suggest that renal afferent nerve activity is increased in hypertension exerting sympathoexcitatory effects. Hence, we wanted to test the hypothesis that in renovascular hypertension, the activity of dorsal root ganglion (DRG) neurons with afferent projections from the kidneys is augmented depending on the degree of intrarenal inflammation. For comparison, a nonhypertensive model of mesangioproliferative nephritis was investigated. Renovascular hypertension (2-kidney, 1-clip [2K1C]) was induced by unilateral clipping of the left renal artery and mesangioproliferative glomerulonephritis (anti-Thy1.1) by IV injection of a 1.75-mg/kg BW OX-7 antibody. Neuronal labeling (dicarbocyanine dye [DiI]) in all rats allowed identification of renal afferent dorsal root ganglion (DRG) neurons. A current clamp was used to characterize neurons as tonic (sustained action potential [AP] firing) or phasic (1–4 AP) upon stimulation by current injection. All kidneys were investigated using standard morphological techniques. DRG neurons exhibited less often tonic response if in vivo axonal input from clipped kidneys was received (30.4% vs. 61.2% control, p < 0.05). However, if the nerves to the left clipped kidneys were cut 7 days prior to investigation, the number of tonic renal neurons completely recovered to well above control levels. Interestingly, electrophysiological properties of neurons that had in vivo axons from the right non-clipped kidneys were not distinguishable from controls. Renal DRG neurons from nephritic rats also showed less often tonic activity upon current injection (43.4% vs. 64.8% control, p < 0.05). Putative sympathoexcitatory and impaired sympathoinhibitory renal afferent nerve fibers probably contribute to increased sympathetic activity in 2K1C hypertension.

Renal sympathetic denervation attenuates left ventricle hypertrophy in spontaneously hypertensive rats by suppressing the Raf/MEK/ERK signaling pathway

OBJECTIVE

To explore the effect of renal sympathetic denervation (RSD) on left ventricle hypertrophy and the Raf/MEK/ERK signaling pathway in spontaneously hypertensive rats (SHRs).

METHODS

SHRs were divided into SHR, SHR + Sham, SHR + RSD and SHR + U0126 groups, with WKY rats as the baseline controls. The blood pressure of rats was observed, while myocardial fibrosis was evaluated through Masson staining. Thereafter, real-time quantitative polymerase chain reaction (qRT-PCR) was carried out to determine the levels of myocardial-hypertrophy-related markers, and Western blotting was used to measure the activity of the Raf/MEK/ERK signaling pathway.

RESULTS

In comparison with the WKY group, significant increases were observed in the systolic pressure and diastolic pressure of rats from the other four groups at different time points after surgery. In addition, rats in these groups had obvious increases in LVMI, renal NE and IVSd and decreases in LVEDd, LVEF and LVFS. In addition, the CVF of myocardial tissues was increased, with the upregulation of ANP, BNP and β-MHC and the downregulation of α-MHC. For the activity of the Raf/MEK/ERK signaling pathway, the levels of p-Raf/Raf, p-MEK/MEK and p-ERK1/2/ERK1/2 were all remarkably elevated (all P < .05). Further comparison with the SHR group showed that the above indexes in the rats were significantly improved in the RSD group and SHR + U0126 group (all P < .05).

CONCLUSION

RSD may decrease blood pressure, mitigate hypertension-induced left ventricle hypertrophy and improve cardiac function efficiently in SHRs via the suppression of the Raf/MEK/ERK signaling pathway.

Superoxide anions modulate the effects of alarin in the paraventricular nucleus on sympathetic activity and blood pressure in spontaneously hypertensive rats

Neuropeptides are involved in the regulation of the sympathetic activity and blood pressure in the paraventricular nucleus of the hypothalamus (PVN). The present study was designed to determine how alarin modulates the renal sympathetic nerve activity (RSNA), arterial blood pressure and mean arterial pressure (MAP) in the PVN, and whether superoxide anions regulate the effects of alarin in the PVN of spontaneously hypertensive rats (SHRs). Acute experiment was carried out with male Wistar-Kyoto rats (WKY) and SHRs under anesthesia. RSNA, systolic blood pressure (SBP), diastolic blood pressure (DBP), and MAP were measured. Alarin microinjection into the PVN increased RSNA (7.8 ± 1.8 vs. 14.8 ± 2.3%), SBP (5.9 ± 1.4 vs. 12.1 ± 1.6 mmHg), DBP (5.1 ± 0.8 vs. 10.0 ± 1.1 mmHg), and MAP (5.4 ± 1.2 vs. 10.7 ± 1.3 mmHg) in WKY rats and SHRs,. Alarin antagonist ala6-25 Cys decreased RSNA, SBP, DBP, and MAP in SHRs, and inhibited the effects of alarin. The alarin level was increased in the PVN of SHR compared to WKY rats. (29.7 ± 4.9 vs. 14.6 ± 2.4 pg/mg protein). PVN microinjection of superoxide anion scavengers tempol and tiron, or NAD(P)H oxidase inhibitor apocynin, decreased RSNA, SBP, DBP, and MAP in SHRs, and inhibited the effects of alarin, but the superoxide dismutase inhibitor diethyldithiocarbamic acid potentiated the effects of alarin. Superoxide anions and NAD(P)H oxidase activity levels in the PVN were increased by alarin, but decreased by alarin antagonist ala6-25 Cys. The alarin-induced increases in superoxide anions and NAD(P)H oxidase activity levels were abolished by pre-treatment with ala6-25 Cys. The results suggest that alarin in the PVN increases sympathetic outflow and blood pressure. The enhanced activity of endogenous alarin in the PVN contributes to sympathetic activation in hypertension, and the superoxide anion is involved in these alarin-mediated processes in the PVN.

Dietary capsaicin-mediated attenuation of hypertension in a rat model of renovascular hypertension

Background: Capsaicin, a pungent component of chili pepper, has been reported to decrease blood pressure (BP) and to cause vasorelaxation via nitric oxide (NO) production. However, it is still unclear how dietary capsaicin effects on renovascular hypertension. To examine this, we observed the effects of dietary capsaicin on BP in 2-kidney, 1-clip renovascular hypertension (2K1C) rats, and investigated the participation of NO in the mechanism.Methods: Rats with 2K1C or sham-operated rats (SHAM) were treated with 0.006% capsaicin diet (CAP) or control diet (CTL) for 6 weeks. Systolic BP (SBP) was measured by tail-cuff method once a week. In the end, mean arterial BP (MAP) was measured in the rats under anesthesia. These observations were performed also in the rats taking a NO synthase (NOS) inhibitor (LN). After rats were euthanized, thoracic aortas were collected and used for western blot analyses to evaluate the phosphorylated ratio of endothelial NOS (eNOS), protein kinase A (PKA) and B (Akt), in order to explore a mechanism of the effects on BP by dietary capsaicin.Results: SBP and MAP in 2K1C rats were significantly higher than in SHAM rats when fed CTL, but not when fed CAP. Those in 2K1C-CAP rats were significantly lower than in 2K1C-CTL rats. LN suppressed the effect of dietary capsaicin. The ratios of phosphorylated (p-) eNOS/eNOS and p-Akt/Akt, but not p-PKA/PKA, were significantly increased in rats fed CAP compared with rats fed CTL.Conclusion: Dietary capsaicin may alleviate 2K1C renovascular hypertension, probably via enhancing phosphorylation of Akt and eNOS.Abbreviations: 2K1C: 2-kidney, 1-clip hypertension model; Akt: protein kinase B; Ang II: angiotensin II; ANOVA: measures analysis of variance; BP: blood pressure; EC: endothelial cell; eNOS: endothelial nitric oxide synthase; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; L-NAME, LN: Nω-Nitro-L-arginine methyl ester hydrochloride; MA: mesenteric arteries; MAP: mean arterial blood pressure; NO: nitric oxide; PKA: protein kinase A; PVDF: polyvinylidene difluoride; SBP: Systolic blood pressure; SHR: spontaneously hypertensive rats; SN: sympathetic nervous; TRPV1: transient receptor potential vanilloid type 1; WKY: Wistar Kyoto rats.

Renal denervation improves sodium excretion in rats with chronic heart failure: effects on expression of renal ENaC and AQP2

Previously we have shown that increased expression of renal epithelial sodium channels (ENaC) may contribute to the renal sodium and water retention observed during chronic heart failure (CHF). The goal of this study was to examine whether renal denervation (RDN) changed the expressions of renal sodium transporters ENaC, sodium-hydrogen exchanger-3 proteins (NHE3), and water channel aquaporin 2 (AQP2) in rats with CHF. CHF was produced by left coronary artery ligation in rats. Four weeks after ligation surgery, surgical bilateral RDN was performed. The expression of ENaC, NHE3, and AQP2 in both renal cortex and medulla were measured. As a functional test for ENaC activation, diuretic and natriuretic responses to ENaC inhibitor benzamil were monitored in four groups of rats (Sham, Sham+RDN, CHF, CHF+RDN). Western blot analysis indicated that RDN (1 wk later) significantly reduced protein levels of α-ENaC, β-ENaC, γ-ENaC, and AQP2 in the renal cortex of CHF rats. RDN had no significant effects on the protein expression of kidney NHE3 in both Sham and CHF rats. Immunofluorescence studies of kidney sections confirmed the reduced signaling of ENaC and AQP2 in the CHF+RDN rats compared with the CHF rats. There were increases in diuretic and natriuretic responses to ENaC inhibitor benzamil in rats with CHF. RDN reduced the diuretic and natriuretic responses to benzamil in CHF rats. These findings suggest a critical role for renal nerves in the enhanced expression of ENaC and AQP2 and subsequent pathophysiology of renal sodium and water retention associated with CHF.NEW & NOTEWORTHY This is the first study to show in a comprehensive way that renal denervation initiated after a period of chronic heart failure reduces the expression of epithelial sodium channels and aquaporin 2 leading to reduced epithelial sodium channel function and sodium retention.

Superoxide anions mediate the effects of angiotensin (1-7) analog, alamandine, on blood pressure and sympathetic activity in the paraventricular nucleus

Microinjection of alamandine into the hypothalamic paraventricular nucleus (PVN) increased blood pressure and enhanced sympathetic activity. The aim of this study was to determine if superoxide anions modulate alamandine's effects in the PVN. Mean arterial pressure (MAP) and renal sympathetic nerve activity (RSNA) were recorded in anaesthetized normotensive Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHRs). Microinjection of alamandine into the PVN increased MAP and RSNA in both WKY rats and SHRs, although to a greater extent in SHRs. These effects were blocked by pretreatment with an alamandine receptor (MrgD) antagonist D-Pro⁷-Ang-(1-7). Pretreatment with superoxide anion scavengers, tempol and tiron, and NADPH oxidase inhibitor apocynin (APO), also blocked the effects of alamandine on MAP and RSNA. In addition, pretreatment in the PVN with a superoxide dismutase (SOD) inhibitor diethyldithiocarbamic acid (DETC) potentiated the increases of MAP and RSNA induced by alamandine administration, with a greater response observed in SHRs. Superoxide anions and NADPH oxidase levels in the PVN were higher in SHRs than that in WKY rats. Alamandine treatment increased the levels of superoxide anions and NADPH oxidase in WKY and SHRs, however, with greater effect in SHRs. These alamandine-induced increases were inhibited by D-Pro⁷-Ang-(1-7) pretreatment in the PVN of both rats. These results demonstrate that superoxide anions in the PVN modulate alamandine-induced increases in blood pressure and sympathetic activity in both normotensive and hypertensive rats. Alamandine increases NADPH oxidase activity to induce superoxide anion production, which is mediated by the alamandine receptor.

Orexin Receptor-1 in the Rostral Ventrolateral Medulla Mediates the Antihypertensive Effects of Electroacupuncture

Electroacupuncture (EA) has been used to treat numerous diseases, including hypertension. This study aimed to investigate the long-term effect and underlying mechanisms of EA stimulation at the LI11 point on the hypertension and sympathetic nerve activity in two-kidney, one-clip (2K1C) hypertensive rats. EA (0.1–0.4 mA, 2 and 15 Hz) was applied to the acupoints LI11 overlying the deep radial nerve once a day for 6 weeks. The mean arterial pressure (MAP) and heart rate (HR) were determined by radiotelemetry, and the sympathetic nerve activity was evaluated by telemetric analyses of the low-frequency component of blood pressure (BP) and by plasma epinephrine and norepinephrine levels. The results showed 6 weeks of EA significantly lowered the increased BP effectively, inhibited the enhanced sympathetic nerve activities and attenuated cardiac hypertrophy in 2K1C hypertensive rats. The level of orexin receptor-1 (OX1R) in the rostral ventrolateral medulla (RVLM) after EA treatment was markedly reduced in 2K1C rats, while there was no difference in the RVLM expression of orexin receptor-2 (OX2R) in 2K1C and 2K1C+EA rats. Moreover, the increased pressor and depressor responses to microinjection of orexin A or OX1R antagonist SB408124 into the RVLM of 2K1C rats were significantly blunted by the EA treatment. These findings suggest that BP-lowering effect of EA on renovascular hypertension may be through inhibition of central sympathetic activities and modulation of functional orexin receptors in the RVLM.

Vaccarin alleviates hypertension and nephropathy in renovascular hypertensive rats

The kidney is an important organ in the regulation of blood pressure, and it is also one of the primary target organs of hypertension. Kidney damage in response to hypertension eventually leads to renal insufficiency. The authors previously demonstrated that vaccarin exhibits a protective role in endothelial injury. However, the effects of vaccarin on the two-kidney, one clip (2K1C) renovascular hypertension model and subsequent kidney injury have yet to be fully elucidated. The present study was designed to investigate the roles and mechanisms of vaccarin in attenuating hypertension and whether vaccarin had beneficial effects on kidney injury. The 2K1C rats had greater fibrosis, apoptosis, reactive oxygen species production, inflammation, angiotensin II (Ang II) and angiotensin type 1 (AT1) receptors in the right kidney compared with normotensive rats, which were alleviated by a high dose of vaccarin and captopril. Vaccarin treatment attenuated hypertension, reduced fibrosis markers, NADPH oxidase (NOX)-2, NOX-4, 3-nitrotyrosine, tumor necrosis factor-α, interleukin 1β (IL-1β), and IL-6 protein levels and altered pro-apoptotic protein levels including caspase-3, anti-apoptosis protein B cell lymphoma (Bcl)-2 and Bcl-2 associated X, apoptosis regulator in the right kidney of 2K1C rats. These findings suggest that the protective effects of vaccarin on the right kidney in renovascular hypertension are possibly due to downregulation of fibrosis, inflammatory molecules, oxidative stress, Ang II, and AT1 receptor levels.

Bilateral superior cervical ganglionectomy attenuates the progression of β-aminopropionitrile-induced aortic dissection in rats

AIMS

Aortic dissection (AD) represents one of the most common aortic emergencies with high incidence of morbidity and mortality. Clinical studies have shown that the increased excitability of the sympathetic nerve may be associated with the formation of AD. In this study, we examined the effects of bilateral superior cervical sympathectomy (SCGx) on the progression of β-aminopropionitrile (BAPN)-induced AD in rats.

MAIN METHODS

Sprague-Dawley rats were randomly divided into three groups, including BAPN, BAPN+SCGx and control groups. For terminal measurements, the mean arterial pressure (MAP) and heart rate (HR) were monitored and the basal sympathetic nerve activity (SNA) was assessed through recording the variation in arterial pressure in response to hexamethonium application. Pathological changes in the aortic wall were observed by histological staining. Matrix metalloproteinase-2 (MMP-2) and MMP-9 concentrations within the aortic wall were analyzed by western blot.

KEY FINDINGS

The results show that BAPN administration could elevate SNA and cause the formation of AD in rats with a high incidence (67.7%), while SCGx treatment inhibited the elevation of SNA and significantly reduced the incidence (20%). SCGx may suppress the formation of BAPN-induced AD via restraining the rise of HR and reducing the MMP-9 concentration in aortic wall.

SIGNIFICANCE

These results indicate that surgical techniques such as sympathetic nerve block may be a potentially useful therapy for the prevention of AD.

Vaccarin administration ameliorates hypertension and cardiovascular remodeling in renovascular hypertensive rats

Sympathetic overdrive, activation of renin angiotensin systems (RAS), and oxidative stress are vitally involved in the pathogenesis of hypertension and cardiovascular remodeling. We recently identified that vaccarin protected endothelial cell function from oxidative stress or high glucose. In this study, we aimed to investigate whether vaccarin attenuated hypertension and cardiovascular remodeling. Two-kidney one-clip (2K1C) model rats were used, and low dose of vaccarin (10 mg/kg), high dose of vaccarin (30 mg/kg), captopril (30 mg/kg) were intraperitoneally administrated. Herein, we showed that 2K1C rats exhibited higher systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), left ventricular mass/body weight ratio, myocardial hypertrophy or fibrosis, media thickness, and media thickness to lumen diameter, which were obviously alleviated by vaccarin and captopril. In addition, both vaccarin and captopril abrogated the increased plasma renin, angiotensin II (Ang II), norepinephrine (NE), and the basal sympathetic activity. The AT1R protein expressions, NADPH oxidase subunit NOX-2 protein levels and malondialdehyde (MDA) content were significantly increased, whereas superoxide dismutase (SOD) and catalase (CAT) activities were decreased in myocardium, aorta, and mesenteric artery of 2K1C rats, both vaccarin and captopril treatment counteracted these changes in renovascular hypertensive rats. Collectively, we concluded that vaccarin may be a novel complementary therapeutic medicine for the prevention and treatment of hypertension. The mechanisms for antihypertensive effects of vaccarin may be associated with inhibition of sympathetic activity, RAS, and oxidative stress.