Protective actions of nebivolol on chronic nitric oxide synthase inhibition-induced hypertension and chronic kidney disease in the rat: a comparison with angiotensin II receptor blockade

Treatment with β-blocker nebivolol ameliorates oxidative stress and endothelial dysfunction in tenofovir-induced nephrotoxicity in rats

Background

Tenofovir disoproxil fumarate (TDF), a widely prescribed component in antiretroviral regimens, has been associated with nephrotoxicity. Nebivolol is a third generation selective β-1 adrenergic receptor blocker and may protect renal structure and function through the suppression of oxidative stress and enhancement of nitric oxide (NO) synthesis. We aimed to investigate whether nebivolol could be an effective therapeutic strategy to mitigate tenofovir-induced nephrotoxicity.

Methods

We allocated Wistar rats to four groups: control (C), received a standard diet for 30 days; NBV, received a standard diet for 30 days added with nebivolol (100 mg/kg food) in the last 15 days; TDF, received a standard diet added with tenofovir (300 mg/kg food) for 30 days; and TDF+NBV, received a standard diet added with tenofovir for 30 days and nebivolol in the last 15 days.

Results

Long-term exposure to tenofovir led to impaired renal function, induced hypertension, endothelial dysfunction and oxidative stress. Nebivolol treatment partially recovered glomerular filtration rate, improved renal injury, normalized blood pressure and attenuated renal vasoconstriction. Administration of nebivolol contributed to reductions in asymmetric dimethylarginine (ADMA) levels as well as increases in endothelial nitric oxide sintase (eNOS) accompanied by renin-angiotensin-aldosterone system downregulation and decreases in macrophage and T-cells infiltrate. Furthermore, nebivolol was responsible for the maintenance of the adequate balance of thiobarbituric acid reactive substances (TBARS) and glutathione (GSH) levels and it was associated with reductions in NADPH oxidase (NOX) subunits.

Conclusion

Nebivolol holds multifaceted actions that promote an advantageous option to slow the progression of kidney injury in tenofovir-induced nephrotoxicity.

Does nebivolol have renoprotective action in patients with chronic kidney disease conditions? An integrative review

Systemic arterial hypertension (SAH) is a chronic disease of multifactorial origin and one of the main risk factors for major adverse cardiovascular events (MACE), which are the leading causes of morbidity and mortality worldwide. The pharmacological treatment of SAH involves five main classes of drugs, and Nebivolol (NEB) is one of those drugs, belonging to the class of third generation β1-adrenoceptors selective blockers. NEB is composed of a racemic mixture of two enantiomers: d-nebivolol, which exerts antagonist effects on β₁-adrenoceptors, and l-nebivolol, a vascular β₃ receptor agonist. There are several studies that report different actions of NEB, not only for the treatment of SAH, but also as an antioxidant agent or even as a protector of renal damage. The aim of this systematic review was to investigate the available evidence regarding the effects of NEB on kidney diseases, evaluating its possible renoprotective action.

Endothelial Dysfunction in Chronic Kidney Disease, from Biology to Clinical Outcomes: A 2020 Update

The vascular endothelium is a dynamic, functionally complex organ, modulating multiple biological processes, including vascular tone and permeability, inflammatory responses, thrombosis, and angiogenesis. Endothelial dysfunction is a threat to the integrity of the vascular system, and it is pivotal in the pathogenesis of atherosclerosis and cardiovascular disease. Reduced nitric oxide (NO) bioavailability is a hallmark of chronic kidney disease (CKD), with this disturbance being almost universal in patients who reach the most advanced phase of CKD, end-stage kidney disease (ESKD). Low NO bioavailability in CKD depends on several mechanisms affecting the expression and the activity of endothelial NO synthase (eNOS). Accumulation of endogenous inhibitors of eNOS, inflammation and oxidative stress, advanced glycosylation products (AGEs), bone mineral balance disorders encompassing hyperphosphatemia, high levels of the phosphaturic hormone fibroblast growth factor 23 (FGF23), and low levels of the active form of vitamin D (1,25 vitamin D) and the anti-ageing vasculoprotective factor Klotho all impinge upon NO bioavailability and are critical to endothelial dysfunction in CKD. Wide-ranging multivariate interventions are needed to counter endothelial dysfunction in CKD, an alteration triggering arterial disease and cardiovascular complications in this high-risk population.

Phenyl sulfate, indoxyl sulfate and p-cresyl sulfate decrease glutathione level to render cells vulnerable to oxidative stress in renal tubular cells

In chronic kidney disease patients, oxidative stress is generally associated with disease progression and pathogenesis of its comorbidities. Phenyl sulfate is a protein-bound uremic solute, which accumulates in chronic kidney disease patients, but little is known about its nature. Although many reports revealed that protein-bound uremic solutes induce reactive oxygen species production, the effects of these solutes on anti-oxidant level have not been well studied. Therefore, we examined the effects of protein-bound uremic solutes on glutathione levels. As a result, indoxyl sulfate, phenyl sulfate, and p-cresyl sulfate decreased glutathione levels in porcine renal tubular cells. Next we examined whether phenyl sulfate-treated cells becomes vulnerable to oxidative stress. In phenyl sulfate-treated cells, hydrogen peroxide induced higher rates of cell death than in control cells. Buthionine sulfoximine, which is known to decrease glutathione level, well mimicked the effect of phenyl sulfate. Finally, we evaluated a mixture of indoxyl sulfate, phenyl sulfate, and p-cresyl sulfate at concentrations comparable to the serum concentrations of hemodialysis patients, and we confirmed its decreasing effect on glutathione level. In conclusion, indoxyl sulfate, phenyl sulfate, and p-cresyl sulfate decrease glutathione levels, rendering the cells vulnerable to oxidative stress.

Protective Effects of the Third Generation Vasodilatory Βeta - Blocker Nebivolol against D-Galactosamine - Induced Hepatorenal Syndrome in Rats

BACKGROUND:

Renal dysfunction is very common in patients with advanced liver cirrhosis and portal hypertension. The development of renal failure in the absence of clinical, anatomical or pathological causes renal of failure is termed hepatorenal syndrome (HRS).

AIM:

The present study was constructed to investigate the possible protective effects of nebivolol (Nebi) against D-galactosamine (Gal)-induced HRS in rats.

MATERIAL AND METHODS:

Rats were treated with Nebi for ten successive days. On the 8th day of the experiment, they received a single dose of Gal. Serum levels of Cr, BUN, Na+ and K+ as well as AST, ALT, total bilirubin (TB), NH3 and endothelin-1 (ET-1) were determined following Gal administration. Moreover, renal and liver contents of MDA, GSH, F2-isoprostanes (F2-IPs), tumor necrosis factor-alpha (TNF-α), nuclear factor kappa-B (NF-κB), total nitric oxide (NO), in addition to activities of caspase-3 (Cas-3), heme oxygenase-1 (HO-1), inducible and endothelial NO synthase (iNOS and eNOS) enzymes were also assessed. Finally, histopathological examination was performed.

RESULTS:

Nebi attenuated Gal-induced renal and hepatic dysfunction. It also decreased the Gal-induced oxidative stress and inflammatory recruitment.

CONCLUSION:

Results demonstrated both nephroprotective and hepatoprotective effects of Nebi against HRS and suggested a role of its antioxidant, anti-inflammatory, anti-apoptotic and NO-releasing properties.

Angiotensin II type 1 receptor antagonists in animal models of vascular, cardiac, metabolic and renal disease

We have reviewed the effects of angiotensin II type 1 receptor antagonists (ARBs) in various animal models of hypertension, atherosclerosis, cardiac function, hypertrophy and fibrosis, glucose and lipid metabolism, and renal function and morphology. Those of azilsartan and telmisartan have been included comprehensively whereas those of other ARBs have been included systematically but without intention of completeness. ARBs as a class lower blood pressure in established hypertension and prevent hypertension development in all applicable animal models except those with a markedly suppressed renin-angiotensin system; blood pressure lowering even persists for a considerable time after discontinuation of treatment. This translates into a reduced mortality, particularly in models exhibiting marked hypertension. The retrieved data on vascular, cardiac and renal function and morphology as well as on glucose and lipid metabolism are discussed to address three main questions: 1. Can ARB effects on blood vessels, heart, kidney and metabolic function be explained by blood pressure lowering alone or are they additionally directly related to blockade of the renin-angiotensin system? 2. Are they shared by other inhibitors of the renin-angiotensin system, e.g. angiotensin converting enzyme inhibitors? 3. Are some effects specific for one or more compounds within the ARB class? Taken together these data profile ARBs as a drug class with unique properties that have beneficial effects far beyond those on blood pressure reduction and, in some cases distinct from those of angiotensin converting enzyme inhibitors. The clinical relevance of angiotensin receptor-independent effects of some ARBs remains to be determined.

Hypoxia: The Force that Drives Chronic Kidney Disease

In the United States the prevalence of end-stage renal disease (ESRD) reached epidemic proportions in 2012 with over 600,000 patients being treated. The rates of ESRD among the elderly are disproportionally high. Consequently, as life expectancy increases and the baby-boom generation reaches retirement age, the already heavy burden imposed by ESRD on the US health care system is set to increase dramatically. ESRD represents the terminal stage of chronic kidney disease (CKD). A large body of evidence indicating that CKD is driven by renal tissue hypoxia has led to the development of therapeutic strategies that increase kidney oxygenation and the contention that chronic hypoxia is the final common pathway to end-stage renal failure. Numerous studies have demonstrated that one of the most potent means by which hypoxic conditions within the kidney produce CKD is by inducing a sustained inflammatory attack by infiltrating leukocytes. Indispensable to this attack is the acquisition by leukocytes of an adhesive phenotype. It was thought that this process resulted exclusively from leukocytes responding to cytokines released from ischemic renal endothelium. However, recently it has been demonstrated that leukocytes also become activated independent of the hypoxic response of endothelial cells. It was found that this endothelium-independent mechanism involves leukocytes directly sensing hypoxia and responding by transcriptional induction of the genes that encode the β2-integrin family of adhesion molecules. This induction likely maintains the long-term inflammation by which hypoxia drives the pathogenesis of CKD. Consequently, targeting these transcriptional mechanisms would appear to represent a promising new therapeutic strategy.

Nebivolol Ameliorates Cisplatin-Induced Nephrotoxicity in Rats

Treatment with cisplatin is associated with dose-limiting side effects, mainly nephrotoxicity. On the other hand, nebivolol, a β1 -adrenoceptor antagonist, exhibits vasodilatory and antioxidative properties. This study aimed to determine whether nebivolol possesses a protective effect against cisplatin nephrotoxicity and explore many mechanisms underlying this potential effect. Nephrotoxicity was induced in Wistar rats by a single intraperitoneal injection of cisplatin (6 mg/kg) on day 2. Nebivolol (10 mg/kg) was administered orally for 7 consecutive days. Nebivolol showed a nephroprotective effect as demonstrated by the significant reduction in the elevated levels of serum creatinine and urea as well as renal levels of malondialdehyde, nitric oxide products (nitrite/nitrate), inducible nitric oxide synthase, tumour necrosis factor-alpha, caspase-3, angiotensin II and endothelin-1 with a concurrent increase in renal levels of reduced glutathione and endothelial nitric oxide synthase compared to untreated rats. Histopathological examination confirmed the nephroprotective effect of nebivolol. Pre-treatment with Nω -nitro-L-arginine methyl ester, the non-specific nitric oxide synthase inhibitor, partially altered the protection afforded by nebivolol. In conclusion, nebivolol protects rats against cisplatin-induced nephrotoxicity that is most likely through its antioxidant, anti-inflammatory and antiapoptotic effects as well as by abrogation of the augmented angiotensin II and endothelin-1 levels.

Correlation between endothelial dysfunction and left ventricular remodeling in patients with chronic kidney disease

BACKGROUND/AIMS

To investigate the role of endothelial dysfunction on left ventricular remodeling in patients with chronic kidney disease and to evaluate the correlation between endothelial dysfunction and left ventricular remodeling.

METHODS

Seventy-three patients with chronic kidney disease as study-group and thirty healthy volunteers as control-group were enrolled in the present study. All patients in both groups had echocardiography examination. The concentration of endothelin-1, nitric oxide, and inducible nitric oxide synthase of serum of all patients and healthy volunteers was measured. The incidence of cardiac structural abnormalities in patients with chronic kidney disease, and the relationship between endothelial dysfunction and cardiac structural abnormalities were analyzed.

RESULTS

The incidence of left ventricular hypertrophy, left ventricular concentric remodeling, and left ventricular systolic dysfunction was 65%, 8.33%, and 16.67%, respectively. The level of endothelin-1 and nitric oxide increased in study-group, and the concentration of inducible nitric oxide synthase decreased. There was significant positively relationship between plasma endothelin-1 and left ventricular mass index, interventricular septal thickness, left ventricular diastolic diameter. There was negatively relationship between the level of serum nitric oxide and the maximum flow velocity at the mitral in left ventricular diastolic stage. There was not any correlation between inducible nitric oxide synthase with left ventricular remodeling.

CONCLUSIONS

The results showed that there was a higher incidence of left ventricular hypertrophy in patients with chronic kidney disease. Endothelin-1 and nitric oxide played an important role on the development of left ventricular hypertrophy.

No evidence of nitrate tolerance caused by nebivolol

BACKGROUND

Continuous long-term treatment with nitrates may cause nitrate tolerance. Nebivolol is a highly selective beta1-adrenergic antagonist with additional nitric oxide (NO)-mediated vasodilatory effects. However, there have been no investigations into whether or not the long-term administration of nebivolol might cause nitrate tolerance.

METHODS

We performed a randomized, double-blind, placebo-controlled, cross-over study in 16 healthy men. Subjects received 5 mg nebivolol or placebo once daily for 8 days in random order divided by a drug-free interval of 2 weeks. Forearm blood flow (FBF) was measured by venous occlusion plethysmography 3 h after oral intake of the first and last doses of nebivolol and placebo, respectively. FBF was measured again following the intravenous administration of 4 μg nitroglycerin/kg body weight/min for 5 min.

RESULTS

Following 8 days of continuous intake of placebo, nitroglycerin increased FBF by 54% (p < 0.05), whereas nitroglycerin increased FBF by 96% (p < 0.01) following 8 days of continuous intake of nebivolol, and the increase after 8 days of nebivolol was significantly (p < 0.05) more pronounced than after 8 days of placebo.

CONCLUSIONS

These findings indicate no evidence of nitrate tolerance caused by long-term administration of nebivolol. On the contrary, long-term intake of nebivolol increases rather than decreases the NO-mediated vasodilating effects.

Effects of voluntary wheel running on the kidney at baseline and after ischaemia-reperfusion-induced acute kidney injury: a strain difference comparison

Exercise-induced vascular endothelial adaptations in the kidney are not well understood. Therefore, we investigated the impact of voluntary wheel running (VWR) on the abundance of endothelial nitric oxide synthase (eNOS) and extracellular superoxide dismutase (EC SOD), in kidney and lung, and other SOD isoforms and total antioxidant capacity (TAC), in kidney. We also determined whether VWR influences susceptibility to acute kidney injury (AKI). Male Sprague-Dawley and Fisher 344 rats, VWR or sedentary for 12 weeks, were subjected to AKI (uninephrectomy (UNX) and 35 min of left kidney ischaemia-24 h reperfusion, IR). We measured glomerular filtration rate (GFR) and renal plasma flow (RPF), and analysed renal structural injury. Running was comparable between strains and VWR reduced body weight. In Sprague-Dawley rats, VWR reduced eNOS and EC SOD, but increased Mn SOD in kidney. Similar changes were seen after 6 weeks of VWR in Sprague-Dawley rats. In Fisher 344 rats, VWR increased eNOS, all SOD isoforms and TAC in kidney. Both strains increased eNOS and EC SOD in lung with VWR. Compared to UNX alone, UNX-IR injury markedly reduced renal function for both strains; however, in the Sprague-Dawley rats, VWR exacerbated falls in GFR and RPF due to UNX-IR, whereas in the Fisher 344 rats, GFR was unaffected by VWR. Some indices of renal structural injury due to UNX-IR tended to be worse in SD vs. F344. Our study demonstrates that genetic background influences the effect of exercise on kidney eNOS and EC SOD, which in turn influence the susceptibility to AKI.

Nebivolol does not protect against 5/6 ablation/infarction induced chronic kidney disease in rats - comparison with angiotensin II receptor blockade

AIMS

Nitric oxide (NO) deficiency contributes to chronic kidney disease progression. Nebivolol, a beta adrenergic receptor antagonist, may enhance endogenous NO. Here, we investigated whether Nebivolol attenuates hypertension and renal injury after 5/6 ablation/infarction (A/I). Efficacy was compared to the AT1 receptor antagonist Olmesartan.

MAIN METHODS

Kidney disease and hypertension were induced by right kidney ablation and ~2/3 infarction of the left kidney. Rats were treated orally with vehicle (placebo), Nebivolol (5mg/kg b.i.d.), or Olmesartan (2.5mg/kg/day) for 6 weeks after A/I.

KEY FINDINGS

With placebo, glomerular sclerosis and tubulointersititial fibrosis developed with increased blood pressure and proteinuria, and a fall in NO(x) excretion. Olmesartan prevented these changes, but Nebivolol had no effect on these measures but lowered heart rate. Neither treatment reduced systemic oxidative stress (urinary hydrogen peroxide and TBARS). Compared to controls, renal cortex abundance of nNOSα decreased and nNOSβ increased in rats after 5/6 A/I, with no changes in eNOS. Neither treatment restored nNOSα; however, both reduced nNOSβ. Activity of DDAH was decreased by 5/6 A/I but restored by both treatments despite no increase in DDAH protein abundance. Kidney cortex abundance of manganese SOD fell after 5/6 A/I and was restored by treatment with Olmesartan but not Nebivolol. Extracellular and copper/zinc SOD abundances were not changed.

SIGNIFICANCE

In conclusion, Nebivolol showed no benefit after 6 weeks in rapidly progressing, ANG II-dependent 5/6 A/I model of chronic kidney disease. This contrasts to the protection seen with 6 month treatment of Nebivolol in the slowly progressing 5/6 ablation model.