| 1. |
- Henrohn, Dan, et al.
(författare)
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Changes in plasma levels of asymmetric dimethylarginine, symmetric dimethylarginine, and arginine after a single dose of vardenafil in patients with pulmonary hypertension
- 2015
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Ingår i: Vascular pharmacology. - : Elsevier BV. - 1537-1891 .- 1879-3649. ; 73, s. 71-77
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: We investigated whether vardenafil, a phosphodiesterase-5 inhibitor, alters plasma levels of asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA), and arginine.PATIENTS AND METHODS: ADMA, SDMA, and arginine were measured (0-540min) in 12 patients with pulmonary hypertension after a single oral dose of vardenafil. Invasive hemodynamic data were collected at baseline and after 60min.RESULTS: A reduction in ADMA was observed at 30 and 45min with a median change of -11.1% (P=0.021) and -12.5% (P=0.002). SDMA decreased with a median -5.3% change (P=0.032) at 45min. An increase in arginine, median 40.3% (P=0.002), 45.0% (P=0.010), and 77.1% (P=0.008) was observed at 120, 300, and 540min respectively. An increase in the arginine/ADMA ratio, median 11.7% (P=0.012), 32.5% (P=0.003), 26.5% (P=0.021), 33% (P=0.007), 48.5% (P=0.007), and 63.1% (P=0.008) was observed at 15, 45, 60, 120, 300, and 540min respectively. There was a positive correlation between vardenafil exposure and the percent change in the arginine/ADMA ratio from baseline to 540min (r=0.80; P=0.01). A correlation between baseline mean right atrial pressure (mRAP) and baseline ADMA (r=0.65; P=0.023), and baseline SDMA (r=0.61; P=0.035) was observed. A correlation between the baseline arginine/ADMA ratio and baseline cardiac output (CO) (r=0.59; P=0.045) and baseline cardiac index (CI) (r=0.61; P=0.036) was observed. Baseline arginine/ADMA ratio correlated with baseline mRAP (r=-0.79; P=0.002). A correlation between change (0-60min) in CI and change in arginine (r=0.77; P=0.003) as well as change in the arginine/ADMA ratio (r=0.61; P=0.037) was observed.CONCLUSIONS: Vardenafil induced changes in ADMA, SDMA, arginine, and the arginine/ADMA ratio in patients with PH. An increase in arginine and the arginine/ADMA ratio was associated with improvement in CI.
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| 2. |
- Henrohn, Dan, et al.
(författare)
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Effects of Oral Supplementation With Nitrate-Rich Beetroot Juice in Patients With Pulmonary Arterial Hypertension-Results From BEET-PAH, an Exploratory Randomized, Double-Blind, Placebo-Controlled, Crossover Study.
- 2018
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Ingår i: Journal of Cardiac Failure. - : Elsevier BV. - 1071-9164 .- 1532-8414. ; 24:10, s. 640-653
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The nitrate-nitrite-nitric oxide (NO) pathway may represent a potential therapeutic target in patients with pulmonary arterial hypertension (PAH). We explored the effects of dietary nitrate supplementation, with the use of nitrate-rich beetroot juice (BRJ), in patients with PAH.METHODS AND RESULTS: We prospectively studied 15 patients with PAH in an exploratory randomized, double-blind, placebo-controlled, crossover trial. The patients received nitrate-rich beetroot juice (∼16 mmol nitrate per day) and placebo in 2 treatment periods of 7 days each. The assessments included; exhaled NO and NO flow-independent parameters (alveolar NO and bronchial NO flux), plasma and salivary nitrate and nitrite, biomarkers and metabolites of the NO-system, N-terminal pro-B-type natriuretic peptide, echocardiography, ergospirometry, diffusing capacity of the lung for carbon monoxide, and the 6-minute walk test. Compared with placebo ingestion of BRJ resulted in increases in; fractional exhaled NO at all flow-rates, alveolar NO concentrations and bronchial NO flux, and plasma and salivary levels of nitrate and nitrite. Plasma ornithine levels decreased and indices of relative arginine availability increased after BRJ compared to placebo. A decrease in breathing frequency was observed during ergospirometry after BRJ. A tendency for an improvement in right ventricular function was observed after ingestion of BRJ. In addition a tendency for an increase in the peak power output to peak oxygen consumption ratio (W peak/VO2 peak) was observed, which became significant in patients reaching an increase of plasma nitrite >30% (responders).CONCLUSIONS: BRJ administered for 1 week increases pulmonary NO production and the relative arginine bioavailability in patients with PAH, compared with placebo. An increase in the W peak/VO2 peak ratio was observed after BRJ ingestion in plasma nitrite responders. These findings indicate that supplementation with inorganic nitrate increase NO synthase-independent NO production from the nitrate-nitrite-NO pathway.
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| 3. |
- Henrohn, Dan
(författare)
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Pulmonary Hypertension and the Nitric Oxide System
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Pulmonary hypertension (PH) is a pathophysiological state associated with several medical conditions, leading to progressive rise in pulmonary vascular resistance (PVR) and right ventricular failure. The clinical PH classification encompasses five main World Health Organization (WHO) groups; pulmonary arterial hypertension (PAH), PH due to left heart disease, PH due to lung diseases and/or hypoxia, chronic thromboembolic PH, and PH with unclear multifactorial mechanisms. Nitric oxide (NO) is a potent vasodilator. Impaired NO production via the classical L-arginine-NO synthase (NOS) pathway has been implicated in PH. Phosphodiesterase-5 (PDE5) inhibitors augment NO signalling, and are considered as one of the cornerstone treatments in PAH. The studies in this thesis aim at to explore and expand the understanding of the NO system in patients with PH.In paper I, we found that PAH patients (WHO group 1) have lower bronchial NO flux compared to healthy controls and patients with PH (WHO group 2–4). This implies reduced bronchial NO formation in PAH. Compared to healthy controls, increased alveolar NO levels were found in patients with PH (WHO group 1-4) and patients with PAH. This may reflect NO diffusion disturbances in the alveoli. PAH patients had higher plasma and salivary levels of nitrite than healthy controls, which may reflect a compensatory upregulation of NOS-independent NO generating pathways.In paper II, we observed that a single oral dose of vardenafil (a PDE5 inhibitor) causes rapid changes in cardiopulmonary haemodynamics in PH patients with PH (WHO group 1-4). We found a correlation between plasma vardenafil concentrations and the changes in mean pulmonary arterial pressure as well as PVR.In paper III, we show that a single oral dose of vardenafil to patients with PH (WHO group 1-4) alter the plasma levels of arginine, asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA), and the arginine/ADMA ratio in a favourable manner. The increase in arginine and the arginine/ADMA ratio were associated with improved cardiac index, and the increase in the arginine/ADMA ratio at 540 min correlated with the exposure to vardenafil. Higher baseline plasma levels of ADMA and SDMA and a low arginine/ADMA ratio was associated with a more severe pulmonary haemodynamic disease state in patients with PH.In paper IV, we found that ingestion of beetroot juice, containing inorganic nitrate, increased plasma and salivary levels of nitrate and nitrite, increased exhaled NO, decreased plasma ornithine levels and increased relative arginine availability in patients with PAH compared to placebo. Higher plasma levels of nitrite after the placebo period, reflecting basal conditions, were associated with a more severe PAH phenotype. Our findings indicate that the nitrate-nitrite-NO pathway is active and upregulated in PAH patients.
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| 4. |
- Sandqvist, Anna, 1980-, et al.
(författare)
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Acute vasodilator response to vardenafil and clinical outcome in patients with pulmonary hypertension
- 2015
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Ingår i: European Journal of Clinical Pharmacology. - : Springer Science and Business Media LLC. - 0031-6970 .- 1432-1041. ; 71:10, s. 1165-1173
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: Acute vasodilator testing is recommended in patients with pulmonary arterial hypertension to identify individuals who may benefit from long-term treatment with oral calcium channel blockers. The aim of this study was to investigate the use of vardenafil in acute vasoreactivity testing compared to adenosine.METHODS: A total of 20 patients eligible for right heart catheterisation were enrolled. Acute vasoreactivity testing was carried out with intravenous (iv) adenosine (n = 18) followed by oral vardenafil (n = 20). Haemodynamic responses were recorded at baseline and after 60 min (vardenafil). Responders were defined according to consensus guideline criteria.RESULTS: Both vardenafil and adenosine significantly decreased mean pulmonary arterial pressure (mPAP, p < 0.001 and p = 0.026, respectively) and pulmonary vascular resistance (p < 0.001 and p > 0.001, respectively), and significantly increased cardiac output (p = 0.001 and p = 0.005, respectively). Vardenafil reduced mPAP more than adenosine (p = 0.044), while adenosine resulted in higher responses of cardiac index (p = 0.009) and pulmonary arterial oxygen saturation (p = 0.042). Acute adverse reactions were common with adenosine, while no side effects were observed after a single oral dose vardenafil. Vardenafil identified five responders (out of 20), while adenosine identified three responders (out of 18). During a 7-year follow-up, vardenafil responders had significantly lower NT-proBNP levels compared to non-responders.CONCLUSIONS: Vardenafil may be safely used for acute vasoreactivity testing in patients with PH. A single oral dose of vardenafil is better tolerated than iv adenosine and may identify additional responders who could benefit from long-term vasodilator treatment.
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