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Singular and combined effects of nebivolol and lifestyle modification on large artery stiffness in hypertensive adults.
Werner, TJ, Boutagy, NE, Osterberg, KL, Rivero, JM, Davy, KP
Therapeutic advances in cardiovascular disease. 2013;(6):285-92
Abstract
BACKGROUND We hypothesized that the combination of nebivolol and lifestyle modification would reduce large artery stiffness in middle-aged and older hypertensive adults more than either intervention alone. METHODS To address this, 45 men and women (age 40-75 years) with stage I hypertension were randomized to receive either nebivolol (NB; forced titration to 10 mg OD; n = 15; age 57.2 ± 11.4 years; body mass index [BMI] 30.8 ± 5.8 kg/m(2)), lifestyle modification (LM; 5-10% weight loss via calorie restriction and physical activity; n = 15; age 52.7 ± 8.5 years; BMI 33.9 ± 7.2 kg/m(2)) or nebivolol plus lifestyle modification (NBLM; n = 15; age 58.9 ± 9.4 years; BMI 32.5 ± 4.9 kg/m(2)) for 12 weeks. β-stiffness index, a blood-pressure-independent measure of arterial stiffness, and arterial compliance were measured via high-resolution ultrasound and tonometry at baseline and after the 12-week intervention. There was no difference between groups in age, body weight or composition, blood pressure, or in β-stiffness index or arterial compliance at baseline (all p > 0.05). RESULTS Following the 12-week intervention, body weight decreased ~5% (p < 0.05) in the LM and NBLM groups but did not change from baseline in the NB group (p > 0.05). Supine brachial and carotid systolic and diastolic blood pressure declined following treatment in each of the groups (p < 0.05). However, the magnitude of reduction was not different (p < 0.05) between groups. β-stiffness index declined (-2.03 ± 0.60, -1.87 ± 0.83 and -2.51 ± 0.90 U) and arterial compliance increased similarly (both p > 0.05) in the NB, LM and NBLM groups, respectively. CONCLUSION In summary, our findings indicate that the combination of nebivolol and lifestyle modification reduced large artery stiffness to a similar degree as either intervention alone in middle-aged and older hypertensive adults.
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The effect of nebivolol treatment on oxidative stress and antioxidant status in patients with cardiac syndrome-X.
Erdamar, H, Sen, N, Tavil, Y, Yazici, HU, Turfan, M, Poyraz, F, Topal, S, Okuyan, H, Cemri, M, Cengel, A
Coronary artery disease. 2009;(3):238-4
Abstract
BACKGROUND Free radical-mediated oxidative stress has been implicated in the etiopathogenesis of several disorders. The aim of this study was to elucidate the effect of treatment with nebivolol on the metabolic state of oxidative stress, and antioxidant status markers in patients with cardiac syndrome-X (CSX), additionally, to compare with the effect of metoprolol treatment. METHODS Thirty patients, 17 female and 13 male, with CSX were enrolled in the study. Nebivolol (5 mg/day) or metoprolol (50 mg/day) was administrated for 12 weeks. Twelve hour fasting blood samples, taken at the initiation and on the third month of therapy, were analyzed for the levels of malondialdehyde (MDA), nitrite+nitrate (NOx), and the activity of myeloperoxidase (MPO), superoxide dismutase (SOD). No patient presented additional risk factors for increased reactive oxygen species levels. RESULTS Compared with sixteen control participants, patients with CSX had significantly higher activity of MPO and levels of MDA, but significantly lower SOD activity and levels of NOx before treatment. After treatment, MPO activity and MDA levels were significantly reduced; SOD activity and NOx levels were significantly increased with nebivolol but remained unchanged with metoprolol. CONCLUSION We have shown that patients with CSX who taken nebivolol have lower serum MPO activity, levels of MDA and higher serum SOD activity, NOx levels when compared with metoprolol treatment. Exercise stress test parameters were also ameliorated in patients who had taken nebivolol in contrast to metoprolol. Nebivolol treatment may be a novel treatment strategy in cases with CSX in the future.
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KATP channel openers of the benzopyran type reach their binding site via the cytosol.
Stephan, D, Salamon, E, Weber, H, Russ, U, Lemoine, H, Quast, U
British journal of pharmacology. 2006;(2):199-205
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Abstract
BACKGROUND AND PURPOSE ATP-sensitive K+ (KATP) channels are composed of pore-forming subunits (Kir6.x) and of sulphonylurea receptors (SUR). Both sulphonylureas and K(ATP) channel openers act by binding to SUR. Sulphonylureas reach their binding site from the cytosol but it remains unknown whether this holds for openers too. EXPERIMENTAL APPROACH A poorly membrane-permeant sulphonic acid derivative of the benzopyran-type opener, bimakalim, was synthesized, descyano-bimakalim-6-sulphonic acid (BMSA). Binding of BMSA and bimakalim was compared in membranes and intact cells expressing the Kir6.2/SUR2B channel and channel opening was compared in inside-out patches and whole cells. KEY RESULTS In membranes, bimakalim and BMSA bound to Kir6.2/SUR2B with Ki values of 61 nM and 4.3 microM, showing that the negative charge decreased affinity 69-fold. In intact cells, however, binding of BMSA was much weaker than in membranes (75-fold) whereas that of bimakalim was unchanged. The Ki value of BMSA decreased with increasing incubation time. In inside-out patches, bimakalim (1 microM) and BMSA (100 microM) opened the Kir6.2/SUR2B channel closed by MgATP to a similar degree whereas in whole-cell experiments, only bimakalim was effective. CONCLUSIONS AND IMPLICATIONS Despite its negative charge, BMSA is an effective channel opener. The fact that BMSA binds and acts more effectively when applied to the inner side of the cell membrane shows that benzopyran openers reach their binding site at SUR from the cytosol. This suggests that the binding pocket of SUR is only open on the cytoplasmic side.
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A comparison of the beta1-selectivity of three beta1-selective beta-blockers.
Nuttall, SL, Routledge, HC, Kendall, MJ
Journal of clinical pharmacy and therapeutics. 2003;(3):179-86
Abstract
OBJECTIVE To determine the relative beta1-selectivity of three beta-blockers (nebivolol, bisoprolol and atenolol), administered orally at normal therapeutic doses, by assessing their impact on the beta2-mediated, haemodynamic and biochemical responses to a terbutaline infusion, which decreases serum potassium and increases serum glucose and insulin. METHODS Twenty-four healthy volunteers (14 men, 10 women), with no history of respiratory disease, attended on five separate occasions; beta-blockers (nebivolol 5 mg, bisoprolol 10 mg, atenolol 50 and 100 mg) or placebo were supplied in random order. Three baseline blood samples were collected at 65-85 min post-beta-blocker. A 60-min terbutaline infusion was started 90 min after taking the beta-blocker. Blood samples were taken and blood pressure and heart rate recorded at 15 min intervals up to 30-min post-infusion. Blood samples were analysed for serum potassium, glucose and insulin concentrations. RESULTS Terbutaline increased heart rate. Pretreatment with nebivolol caused a modest and non-significant reduction in terbutaline-induced tachycardia whilst bisoprolol produced a more marked effect. Atenolol at both 50 and 100 mg doses caused a highly significant reduction in terbutaline-induced tachycardia. All active preparations had a comparable impact on the terbutaline-induced increase in systolic blood pressure, but the drugs had no impact on the changes produced in diastolic blood pressure. After pretreatment with placebo, the terbutaline infusion caused a significant decrease in serum potassium and increases in serum glucose and insulin. Pretreatment with nebivolol had no discernible effect on potassium compared with placebo. In contrast, when compared with either placebo or nebivolol, bisoprolol (P < 0.01) and both doses of atenolol (P < 0.001) significantly attenuated the hypokalaemic effect of terbutaline. Treatment with nebivolol and bisoprolol modestly but significantly reduced the terbutaline-induced increases in glucose (P < 0.05). The blocking effects of both doses of atenolol were highly significant (P < 0.001) when compared with placebo and also significant (P < 0.05 and P < 0.01, respectively) when compared with nebivolol and bisoprolol. A similar pattern of responses with the different beta-blocker treatments was observed for the effects on insulin concentrations during the terbutaline infusion. CONCLUSION The beta1-selectivity of three different beta1-blockers has been demonstrated in healthy volunteers using the blocking of biochemical and haemodynamic responses to a beta2 stimulus. Terbutaline alone caused an increase in heart rate, a rise in systolic blood pressure, a fall in serum potassium and a rise in both serum glucose and insulin. In this study, for both haemodynamic and biochemical responses, atenolol 100 mg had the greatest beta2-blocking effect, nebivolol 5 mg the least. Bisoprolol 10 mg and atenolol 50 mg had intermediate effects; bisoprolol was the more beta1-selective of these two.