Endothelin Receptor Blockade Improves Cerebral Blood Flow-Mediated Dilation in a Mouse Model of Alzheimer's Disease

INTRODUCTION

Cerebral blood flow (CBF) is reduced in patients with Alzheimer's disease (AD). Flow-mediated dilation (FMD), which plays a key role in the regulation of blood flow, is attenuated by endothelin-1. We hypothesized that endothelin receptor blockade may improve CBF in AD.

METHODS

We investigated cerebrovascular reactivity in a mouse model of AD (APP-PS1; 5-6-month-old male subjects). We assessed the in vivo response to normoxic hypercapnia and in vitro FMD in isolated cerebral and mesenteric resistance arteries before and after endothelin receptor blockade (bosentan).

RESULTS

Normoxic hypercapnia increased basilar trunk blood flow velocity (+12.3 ± 2.4%; p = 0.006, n = 6) in wild-type (WT) mice but reduced blood flow in APP-PS1 mice (-11.4 ± 1.2%; p < 0.0001, n = 8). Bosentan (50 mg/kg, acute intraperitoneal injection) restored cerebrovascular reactivity in APP-PS1 mice (+10.2 ± 2.2%; p < 0.0001, n = 8) but had no effect in WT. FMD was reduced in the posterior cerebral artery of APP-PS1 compared to WT and was normalized by bosentan (1 μmol/L, 30 min, or 50 mg/kg/day for 28 days). FMD was similar in the mesenteric artery of APPS-PS1 and WT.

CONCLUSION

APP-PS1 mice exhibited cerebrovascular endothelial dysfunction. Acute and chronic blockade of endothelin receptors restored endothelial vasomotor function, suggesting a promising therapeutic approach to restoring cerebral vasoreactivity in AD.

Development and pharmacokinetic evaluation of Neusilin® US2-based S-SNEDDS tablets for bosentan: Fasted and fed states bioavailability, IVIS® real-time biodistribution, and ex-vivo imaging

The study reported here aimed to develop and optimize the S-SNEDDS tablet of bosentan (BOS) and to investigate its pharmacokinetic and biodistribution properties. The BOS-loaded SNEDDS have been developed and characterized in a previous study. The BOS-loaded SNEDDS formulation was converted to S-SNEDDS using Neusilin® US2. The S-SNEDDS tablets were obtained using the direct compression technique, and in vitro dissolution, in vitro lipolysis, and ex-vivo permeability studies of the tablets were performed. The S-SNEDDS tablet and reference tablet (Tracleer®) were administered to male Wistar rats at 50 mg/kg dose by oral gavage in fasted and fed state conditions. The biodistribution of the S-SNEDDS tablet was investigated in Balb/c mice using fluorescent dye. The tablets were dispersed in distilled water before administration to animals. The relationship between in vitro dissolution data and in vivo plasma concentration was examined. The S-SNEDDS tablets showed 2.47, 7.49, 3.70, and 4.39 increases in the percentages of cumulative dissolution in FaSSIF, FeSSIF, FaSSIF-V2, and FeSSIF-V2, respectively, when compared to the reference, and increased the Cmax and AUC 2.65 and 1.28-fold and 4.73 and 2.37-fold in fasted and fed states, respectively, when compared to the reference. S-SNEDDS tablets also significantly reduced interindividual variability in both fasted and fed states (p < 0.05). The XenoLight™ DiR and VivoTag® 680XL labeled S-SNEDDS tablet formulation increased the real-time biodistribution in the body by factors of 2.4 and 3.4 and organ uptake and total emission increased by factors of 2.8 and 3.1, respectively. The IVIVR has been successfully established for S-SNEDDS tablets (R2 > 0.9). The present study confirms the potential of the S-SNEDDS tablet to enhance the in vitro and in vivo performance of BOS.

Cost-utility of ambrisentan and bosentan for pediatric pulmonary arterial hypertension

INTRODUCTION

Despite the increasing evidence supporting the efficacy of ambrisentan and bosentan in improving functional classes among pediatric patients with pulmonary arterial hypertension (PAH), there is a lack of information regarding their cost implications. Therefore, the objective of this study is to assess the cost-utility of bosentan compared to ambrisentan for the treatment of pediatric patients with PAH in Colombia.

METHODS

We employed a Markov model to estimate the costs and quality-adjusted life-years (QALYs) associated with the use of ambrisentan or bosentan in pediatric patients diagnosed with pulmonary arterial hypertension (PAH). To ensure the reliability of our findings, we conducted sensitivity analyses to assess the robustness of the model. In our cost-effectiveness analysis, we evaluated the outcomes at a willingness-to-pay (WTP) threshold of US$5,180.

RESULTS

The expected annual cost per patient receiving ambrisentan was estimated to be $16,055 (95% CI 15,937 -16,172), while for bosentan it was $14,503 (95% CI 14,489 -14,615). The QALYs per person estimated for ambrisentan were 0.39 (95% CI 0.381-0.382), whereas for bosentan it was 0.40 (95% CI 0.401-0.403).

CONCLUSION

Our economic evaluation shows that ambrisentan is not cost-effective regarding bosentan to in treating pulmonary arterial hypertension in C.

Comprehensive Update on Synthetic Aspects of Bosentan Derivatives

Bosentan and its analogues were first reported as endothelin (ET) receptor antagonists in US patent No. 5, 292,740 in 1994. Bosentan synthesis has been reported by employing different methods from the reaction between (4,6-dichloro-5-(2-methoxyphenoxy)-2,2'-bipyrimidine and 4- (tert-butyl) benzenesulfonamide and 4-(tert-butyl)-N-(6-chloro-5-(2-methoxyphenoxy)-[2,2'- bipyrimidin]-4-yl) benzenesulfonamide in the form of different salts like potassium salt, ammonium salt, sodium salt, and free, on its reaction with ethylene glycol. Several changes have been observed in the chemistry of the involved intermediate synthesis, particularly coupling chemistry, to produce bosentan derivatives with high purity and yield.

Endothelin receptor antagonism improves glucose tolerance and adipose tissue inflammation in an experimental model of systemic lupus erythematosus

Endothelin-1 (ET-1) is elevated in patients with systemic lupus erythematosus (SLE), an autoimmune disease characterized by high rates of hypertension, renal injury, and cardiovascular disease. SLE is also associated with an increased prevalence of obesity and insulin resistance compared to the general population. In the present study, we tested the hypothesis that elevated ET-1 in SLE contributes to obesity and insulin resistance. For these studies, we used the NZBWF1 mouse model of SLE, which develops obesity and insulin resistance on a normal chow diet. To test this hypothesis, we treated control (NZW) and SLE (NZBWF1) mice with vehicle, atrasentan (ETA receptor antagonist, 10 mg/kg/day), or bosentan (ETA/ETB receptor antagonist, 100 mg/kg/day) for 4 wk. Neither treatment impacted circulating immunoglobulin levels, but treatment with bosentan lowered anti-dsDNA IgG levels, a marker of SLE disease activity. Treatment with atrasentan and bosentan decreased glomerulosclerosis, and atrasentan lowered renal T-cell infiltration. Body weight was lower in SLE mice treated with atrasentan or bosentan. Endothelin receptor antagonism also improved hyperinsulinemia, homeostatic model assessment for insulin resistance, and glucose tolerance in SLE mice. Adipose tissue inflammation was also improved by endothelin receptor blockade. Taken together, these data suggest a potential therapeutic benefit for SLE patients with obesity and insulin resistance.NEW & NOTEWORTHY SLE is an autoimmune disease that is associated with obesity, insulin resistance, and elevated endothelin-1. The present study demonstrated that pharmacological inhibition of endothelin receptors decreased body weight, insulin resistance, and adipose tissue inflammation in a murine model of SLE. The therapeutic potential of endothelin receptor antagonists to treat obesity-related diseases and pathophysiological conditions, such as autoimmune diseases and insulin resistance, has become increasingly clear.

Role of endothelin in the pathophysiology of migraine: A new view on an old player

There is cumulating evidence that endothelin-1 (ET-1) may play a role in migraine, however controversial findings still impede a conclusion to be drawn. Herein we tested the hypothesis that endothelin ETB receptors are major contributors to migraine-like responses. ET-1, IRL-1620 (selective ETB receptor agonist) or CGRP were injected into the trigeminal ganglion (TG) of female Wistar rats, and the development of periorbital mechanical allodynia was assessed hourly with von Frey hairs. Twenty-four hours later, rats were exposed to an aversive light for 1 h, after which the reactivation of periorbital mechanical allodynia (indicating photic sensitivity) was assessed up to 4 h. Moreover, the effect of systemic Bosentan (ETA/ETB receptors antagonist) or the selective antagonists of ETA (BQ-123) and ETB (BQ-788) receptors injected into the TG were evaluated against CGRP-induced responses. ET-1 and IRL-1620 injection into the TG induced periorbital mechanical allodynia and photic sensitivity. Bosentan attenuated periorbital mechanical allodynia but failed to affect photic sensitivity induced by CGRP. Selective blockade of ETB receptors in the TG fully prevented the development of periorbital mechanical allodynia and photic sensitivity induced by CGRP, but ETA receptor blockade caused only a slight reduction of periorbital mechanical allodynia without affecting photic sensitivity. ETB receptor-operated mechanisms in the TG may contribute to migraine-like responses in female rats.

Endothelin-1 receptor blockade does not alter the sympathetic and hemodynamic response to acute intermittent hypoxia in men

Repeat exposures to low oxygen (intermittent hypoxia, IH), like that observed in sleep apnea, elicit increases in muscle sympathetic nerve activity (MSNA) and blood pressure (BP) in men. Endothelin (ET) receptor antagonists can attenuate the sympathetic and BP response to IH in rodents; whether these data translate to humans are unclear. We hypothesized that ET-receptor antagonism would ameliorate any rise in MSNA and BP following acute IH in humans. Twelve healthy men (31 ± 1 yr) completed two visits (control, bosentan) separated by at least 1 wk. MSNA, BP, and baroreflex sensitivity (modified Oxford) were assessed during normoxic rest before and following 30 min of IH. The midpoint (T50) for each individual's baroreflex curve was calculated. Acute IH increased plasma ET-1 (P < 0.01), MSNA burst frequency (P = 0.03), and mean BP (P < 0.01). There was no effect of IH on baroreflex sensitivity (P = 0.46), although an increase in T50 was observed (P < 0.01). MSNA burst frequency was higher (P = 0.04) and mean BP (P < 0.01) was lower following bosentan treatment compared with control. There was no effect of bosentan on baroreflex sensitivity (P = 0.53), although a lower T50 was observed on the bosentan visit (P < 0.01). There was no effect of bosentan on increases in MSNA (P = 0.81) or mean BP (P = 0.12) following acute IH. Acute IH results in an increase in ET-1, MSNA, and BP in healthy young men. The effect of IH on MSNA and BP is not attenuated following ET-receptor inhibition. Present data suggest that acute IH does not increase MSNA or BP through activation of ET-receptors in healthy young men.NEW & NOTEWORTHY Repeat exposures to low oxygen (intermittent hypoxia, IH) elicit increases in muscle sympathetic nerve activity (MSNA) and blood pressure (BP) in men. Endothelin (ET) receptor antagonists can attenuate the sympathetic and BP response to IH in rodents; whether these data translate to humans were unclear. We show acute IH results in an increase in ET-1, MSNA, and BP in healthy young men; however, the effect of IH on MSNA and BP does not occur through activation of ET-receptors in healthy young men.

Endothelin-axis antagonism enhances tumor perfusion in pancreatic cancer

Delivery of therapeutic agents in pancreatic cancer (PC) is impaired due to its hypovascular and desmoplastic tumor microenvironment. The Endothelin (ET)-axis is the major regulator of vasomotor tone under physiological conditions and is highly upregulated in multiple cancers. We investigated the effect of dual endothelin receptor antagonist bosentan on perfusion and macromolecular transport in a PC cell-fibroblast co-implantation tumor model using Dynamic Contrast-Enhanced Magnetic Resonance Imaging (DCE-MRI). Following bosentan treatment, the contrast enhancement ratio and wash-in rates in tumors were two- and nine times higher, respectively, compared to the controls, whereas the time to peak was significantly shorter (7.29 ± 1.29 min v/s 22.08 ± 5.88 min; p = 0.04). Importantly, these effects were tumor selective as the magnitudes of change for these parameters were much lower in muscles. Bosentan treatment also reduced desmoplasia and improved intratumoral distribution of high molecular weight FITC-dextran. Overall, these findings support that targeting the ET-axis can serve as a potential strategy to selectively enhance tumor perfusion and improve the delivery of therapeutic agents in pancreatic tumors.

Dual endothelin receptor antagonism increases resting energy expenditure in people with increased adiposity

Increased adiposity is associated with dysregulation of the endothelin system, both of which increase the risk of cardiovascular disease (CVD). Preclinical data indicate that endothelin dysregulation also reduces resting energy expenditure (REE). The objective was to test the hypothesis that endothelin receptor antagonism will increase REE in people with obesity compared with healthy weight individuals. Using a double blind, placebo-controlled, crossover design, 32 participants [healthy weight (HW): n = 16, BMI: 21.3 ± 2.8 kg/m2, age: 26 ± 7 yr and overweight/obese (OB): n = 16, BMI: 33.5 ± 9.5 kg/m2, age: 31 ± 6 yr] were randomized to receive either 125 mg of bosentan (ETA/B antagonism) or placebo twice per day for 3 days. Breath-by-breath gas exchange data were collected and REE was assessed by indirect calorimetry. Venous blood samples were analyzed for concentrations of endothelin-1 (ET-1). Treatment with bosentan increased plasma ET-1 in both OB and HW groups. Within the OB group, the changes in absolute REE (PLA: -77.6 ± 127.6 vs. BOS: 72.2 ± 146.6 kcal/day; P = 0.046). The change in REE was not different following either treatment in the HW group. Overall, absolute plasma concentrations of ET-1 following treatment with bosentan were significantly associated with kcal/day of fat (r = 0.488, P = 0.005), percentage of fat utilization (r = 0.415, P = 0.020), and inversely associated with the percentage of carbohydrates (r = -0.419, P = 0.019), and respiratory exchange ratio (r = -0.407, P = 0.023). Taken together, these results suggest that modulation of the endothelin system may represent a novel therapeutic approach to increase both resting metabolism and caloric expenditure, and reduce CVD risk in people with increased adiposity.NEW & NOTEWORTHY Findings from our current translational investigation demonstrate that dual endothelin A/B receptor antagonism increases total REE in overweight/obese individuals. These results suggest that modulation of the endothelin system may represent a novel therapeutic target to increase both resting metabolism and caloric expenditure, enhance weight loss, and reduce CVD risk in seemingly healthy individuals with elevated adiposity.

[Efficacy and safety of endothelin receptor antagonists combined with phosphodiesterase 5 inhibitor in the treatment of pulmonary arterial hypertension: a network meta-analysis]

Objective: To examine the efficacy and safety of endothelin receptor antagonists (ERA) combined with phosphodiesterase 5 inhibitors (PDE5i) in the treatment of pulmonary artery hypertension (PAH). Methods: Computer-based retrieval was performed on PubMed, Cochrane Library, CNKI, Wanfang, and VIP database (up to February 12th, 2021). Randomized controlled trials about endothelin receptor antagonists (ERAs) or PDE5i in patients with PAH were collected. The change of 6-minute walking distance (6MWD) in 12-16 weeks was used as primary outcome index. Case fatality rate, worsening clinical events, WHO functional class (FC) improvement, adverse events (AEs), serious adverse events (SAE) were the key secondary outcomes indicators. STATA 16.0 software was used for network meta-analysis, and the pooled estimates of odds ratios (ORs) or weighted mean differences (WMDs) and 95% confidence intervals (CIs) of the results were shown. To help explain ORs and WMDs, we used the surface under the cumulative ranking curve (SUCRA) to calculate the probability of each intervention. Results: We included 29 trials with 5 949 participants. In network meta-analysis, Bosentan combined with Sildenafil (WMD=53.93, 95%CI=6.19-101.66) had shown the greatest improvement in 6MWD compared with placebo, followed by Bosentan combined with Tadalafil (WMD=50.84, 95%CI=7.05-94.62), Ambrisentan combined with Tadalafil (WMD=46.67, 95%CI=15.88-77.45), Bosentan (WMD=29.44, 95%CI=5.86-53.02), Ambrisentan (WMD=23.90, 95%CI=0.31-47.48) and Macitentan (WMD=21.57, 95%CI=2.45-40.69). According to SUCRA, the effects of different intervention measures on improving 6MWD in patients with arterial pulmonary hypertension were as follows: Bosentan+Sildenafil (82.9%)>Bosentan+Tadalafil (78.4%)>Ambrisentan+Tadalafil (77.1%)>Bosentan (49.2%)>Sildenafil (48.5%)>Ambrisentan (40.3%)>Macitentan (37.3%)>Tadalafil (33.0%)>Placebo (3.3%). For the WHO functional class, Sildenafil (OR=2.90, 95%CI=1.04-8.08) was optimal compared with placebo, followed by Bosentan (OR=2.15, 95%CI=1.15-4.04), and there was no significant difference in the rest. For clinical worsening, Bosentan combined with Tadalafil (OR=0.08, 95%CI=0.01-0.49) performed best compared with placebo, followed by Bosentan (OR=0.20, 95%CI=0.11-0.38), Bosentan combined with Sildenafil (OR=0.21, 95%CI=0.09-0.46), Ambrisentan combined with Tadalafil (OR=0.27, 95%CI=0.15-0.50), Sildenafil (OR=0.33, 95%CI=0.17-0.66) and Tadalafil (OR=0.44, 95%CI=0.21-0.90). There was no statistical difference between all interventions and placebo in terms of the incidence of adverse events and serious adverse events. For case fatality rate, Ambrisentan (OR=0.28, 95%CI=0.11-0.74) was statistically superior to placebo and there was no statistics difference in the rest. Conclusions: The combination therapy of ERAs and PDE5i performed well in the short-term improvement of motor function. Furthermore, there was no significant difference with monotherapy in terms of safety. However, it is worth emphasizing that the choice of treatment should be based on the patient's individualized situation and the patient's requirements.

Systematic review and cost-effectiveness of bosentan and sildenafil as therapeutic drugs for pediatric pulmonary arterial hypertension

BACKGROUND

Pulmonary arterial hypertension (PAH) is a rare disease in children, with significant mortality. Because of the limited research on pediatric PAH, first, systematic review of related drugs is conducted, and then economic evaluation of PAH drug treatment programs is conducted, which to provide a reference for the choice of more cost-effective treatment options.

METHODS

The search includes electronic databases such as Pubmed, ScienceDirect, and Embase. Through inclusion and exclusion criteria, screen high-quality randomized controlled trials. We used TreeAge Pro 2011 software to construct the markov model, that to simulate the total medical cost and quality-adjusted life years (QALYs), and to calculate the incremental cost-effectiveness ratio. Sensitivity analysis of transfer probability, utility, and cost was carried out.

RESULTS

Incorporate two studies that meet the criteria, one compared the therapeutic effects of bosentan and placebo on pediatric PAH, the other compared therapeutic effects of sildenafil and placebo on pediatric PAH, both articles were of good quality. Compared with the sildenafil group (3.38QALYs and $161,120.14), the QALY of the bosentan treatment group (3.33QALYs and $257,411.29) was reduced by 0.05, and the cost increased by $96,291.15. The estimated improvement to quality of life and reduced costs result in an estimate of economic dominance for sildenafil over bosentan. This dominant result persisted probabilistic analyses.

CONCLUSIONS

Based on this model, a more cost-effective treatment drug for PAH in children is sildenafil.

Ameliorative role of bosentan, an endothelin receptor antagonist, against sodium arsenite-induced renal dysfunction in rats

Arsenic exposure is well documented to cause serious health hazards, such as cardiovascular abnormalities, neurotoxicity and nephrotoxicity. In the present study, we intended to explore the role of bosentan, an endothelial receptor antagonist, against sodium arsenite-induced nephrotoxicity and hepatotoxicity in rats. Sodium arsenite (5 mg/kg, oral) was administered for 4 weeks to induce renal dysfunction in rats. Sodium arsenite intoxicated rats were treated with bosentan (50 and 100 mg/kg, oral) for 4 weeks. Arsenic led renal damage was demonstrated by significant increase in serum creatinine, urea, uric acid, potassium, fractional excretion of sodium, microproteinuria and decreased creatinine clearance in rats. Sodium arsenite resulted in marked oxidative stress in rat kidneys as indicated by profound increase in lipid peroxides, and superoxide anion generation alongwith decrease in reduced glutathione levels. Hydroxyproline assay highlighted arsenic-induced renal fibrosis in rats. Hematoxylin-eosin staining indicated glomerular and tubular changes in rat kidneys. Picrosirius red staining highlighted collagen deposition in renal tissues of arsenic treated rats. Immunohistological results demonstrated the reduction of renal eNOS expression in arsenic treated rats. Notably, treatment with bosentan attenuated arsenic-induced renal damage and resisted arsenic-led reduction in renal eNOS expression. In addition, sodium arsenite-induced alteration in hepatic parameters (serum aspartate aminotransferase, alanine transferase, alkaline phosphatase, bilirubin), oxidative stress and histological changes were abrogated by bosentan treatment in rats. Hence, we conclude that bosentan treatment attenuated sodium arsenite-induced oxidative stress, fibrosis and reduction in renal eNOS expression in rat kidneys. Moreover, bosentan abrogated arsenic led hepatic changes in rats.

Bosentan therapy for pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension: A systemic review and meta-analysis

BACKGROUND AND OBJECTIVE

Bosentan therapy has been recommended for pulmonary arterial hypertension (PAH) and might be beneficial for chronic thromboembolic pulmonary hypertension (CTEPH). We aimed to evaluate the specific effects of bosentan for PAH and CTEPH.

MATERIALS AND METHODS

We performed a systemic review and meta-analysis of randomized controlled trials (RCTs), comparing efficacy and safety of bosentan treatment for PAH and CTEPH through major biomedical database.

RESULTS

A total of 10 RCTs including 1185 patients were enrolled. For PAH patients, bosentan prolonged 6-minute walk distance with a weighted mean difference of 35.7 m, reduced mean pulmonary arterial pressure by 5.7 mm Hg, increased cardiac index by 0.4 L/min/m2 , reduced pulmonary vascular resistance by 305.1 dyn·s/cm5 , prevented functional class from deterioration and reduced clinical worsening as compared with placebo. For CTEPH patients, bosentan improved cardiac index by 0.3 L/min/m2 and reduced pulmonary vascular resistance by 176.0 dyn·s/cm5 . Other efficacy outcomes regarding CTEPH did not attain statistical difference. For both PAH and CTEPH, there was no significant difference in mortality or adverse event between bosentan and placebo group. However, bosentan raised the risk of abnormal liver function in both PAH and CTEPH patients.

CONCLUSIONS

Bosentan is effective in treating PAH, whereas it improves only certain hemodynamic parameters of CTEPH. Incidence of liver function abnormality is higher in bosentan treatment.

Intravital Multiphoton Microscopy with Fluorescent Bile Salts in Rats as an In Vivo Biomarker for Hepatobiliary Transport Inhibition

The bile salt export pump (BSEP) is expressed at the canalicular domain of hepatocytes, where it mediates the elimination of monovalent bile salts into the bile. Inhibition of BSEP is considered a susceptibility factor for drug-induced liver injury that often goes undetected during nonclinical testing. Although in vitro assays exist for screening BSEP inhibition, a reliable and specific method for confirming Bsep inhibition in vivo would be a valuable follow up to a BSEP screening strategy, helping to put a translatable context around in vitro inhibition data, incorporating processes such as metabolism, protein binding, and other exposure properties that are lacking in most in vitro BSEP models. Here, we describe studies in which methods of quantitative intravital microscopy were used to identify dose-dependent effects of two known BSEP/Bsep inhibitors, 2-[4-[4-(butylcarbamoyl)-2-[(2,4-dichlorophenyl)sulfonylamino]phenoxy]-3-methoxyphenyl]acetic acid (AMG-009) and bosentan, on hepatocellular transport of the fluorescent bile salts cholylglycyl amidofluorescein and cholyl-lysyl-fluorescein in rats. Results of these studies demonstrate that the intravital microscopy approach is capable of detecting Bsep inhibition at drug doses well below those found to increase serum bile acid levels, and also indicate that basolateral efflux transporters play a significant role in preventing cytosolic accumulation of bile acids under conditions of Bsep inhibition in rats. Studies of this kind can both improve our understanding of exposures needed to inhibit Bsep in vivo and provide unique insights into drug effects in ways that can improve our ability interpret animal studies for the prediction of human drug hepatotoxicity.

The Effect of Endothelin Receptor Antagonists in Patients with Eisenmenger Syndrome: A Systematic Review

INTRODUCTION

The efficacy of endothelin receptor antagonists (ERAs) in the management of Eisenmenger syndrome (ES) remains controversial. The aim of this study is to systemically review the safety and effects of ERAs in improving the quality of life and basic cardiac functions of these patients.

METHODS

Twelve databases were searched, including PubMed, Web of Science, Scopus, Virtual Health Library, World Health Organization (WHO) Global Health Library, Google Scholar, POPLINE, Systems for Information of Grey Literature in Europe, New York Academy of Medicine, ClinicalTrials.gov, metaRegister of Controlled Trials and the WHO International Clinical Trials Registry Platform, through August 2016. We included randomized clinical trials addressing the effect of ERAs on cardiac functions in patients with ES. The quality of studies was assessed using the Cochrane Collaboration tool.

RESULTS

We included two trials represented by four papers, of which three papers reported the efficacy of bosentan against placebo and one paper reported the results of a combination of bosentan and sildenafil versus placebo and bosentan. One trial showed a significant effect of bosentan treatment over placebo on indexed pulmonary vascular resistance and mean pulmonary artery pressure, but a non-significant increase in 6-min walk distance and a non-significant effect on systemic pulse oximetry. The other trial reported the safe but non-significant effect of combination therapy of bosentan and sildenafil compared with bosentan and placebo.

CONCLUSIONS

This study demonstrated safety and improved hemodynamic effects of bosentan in ES, with a controversial effect on exercise capacity. Further randomized controlled trials with longer follow-up duration are needed to confirm these results.

Clinical and histopathological relationship of sildenafil and bosentan treatments in rats with monocrotaline induced pulmonary hypertension

BACKGROUND

Pulmonary arterial hypertension (PAH) is a challenging disorder characterized by increasing pulmonary artery pressure, which is hard to treat.

OBJECTIVE

This study was aimed to investigate the effects of bosentan, sildenafil and their combination.

METHODS

Saline or MCT were applied to Wistar rats. By the development of PAH (4th week), MCT-given rats were treated orally with bosentan, sildenafil and combination of sildenafil and bosentan or placebo. ECHO examinations were performed. Tissues obtained from all of the rats were evaluated under an electron microscope.

RESULTS

Left ventricular end diastolic diameter significantly increased in sildenafil and combined groups. Sildenafil group revealed a significant decrease in RV pressure and wall thickness. Examination of lung revealed a significant amount of connective tissue formation and increase in inflammatory cells in all the groups except controls in the interalveolar septum. Examination of PA revealed an increase in connective tissue volume, hypertrophic changes and expansions in granular endoplasmic reticulum cisternaes in smooth muscle cells in active groups rather than in the controls. Unlike the controls, the examination of the RV revealed an enlargement of the sarcoplasmic reticulum cisternaes in some cells, due to the calcium increase.

CONCLUSION

Sildenafil and the combined therapy demonstrated to have more impact on pressure and the RV parameters in rats, with lower inflammatory findings in lung tissue (Fig. 6, Ref. 31).

The efficiency of endothelin receptor antagonist bosentan for pulmonary arterial hypertension associated with congenital heart disease: A systematic review and meta-analysis

BACKGROUND

Oral bosentan has been widely applied in pulmonary arterial hypertension associated with congenital heart disease (PAH-CHD). A systemic review and meta-analysis was conducted for a therapeutic evaluation of oral bosentan in both adult and pediatric patients with PAH-CHD. The acute responses and a long-term effect were respectively assessed in a comparison with baseline characteristics, and the improvement of exercise tolerance was analyzed.

METHODS

PubMed, Medline, Embase, and Cochrane Central Register of clinical controlled trails or observational studies have been searched for a recording of bosentan effects on the PAH-CHD participants. For mortality and rate of adverse events (AEs), it was described in detail. Randomized-effects model or fixed-effects model was used to calculate different effective values with a sensitivity analysis.

RESULTS

Seventeen studies were pooled in this review, and 3 studies enrolled the pediatric patients. Among all studies, 456 patients were diagnosed with PAH-CHD, and 91.7% were treated with oral bosentan. With a term less than 6 months of bosentan therapy, there existed a significant improvement in 6-minute walk distance (6MWD) and the World Health Organization functional class (WHO-FC), but no such differences in Borg dyspnea index scores (BDIs) and the resting oxygen saturation (SpO2). Although with a prolonged treatment, not only 6MWD and FC, but also the resting SpO2 and heart rate were changed for a better exercise capability. Additionally, compared with the basic cardiopulmonary hemodynamics, it showed a statistically significant difference in mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance index (PVRi). Although a limitation of pooled studies with comparative outcomes of different terms, outcomes presented a lower WHO-FC which contributes to a success in a prolonged treatment.

CONCLUSIONS

Bosentan in PAH-CHD is well established and still requires clinical trials for an identification of its efficiency on CHD patients for an optimized period lessening a serious complication and the common AEs.

[Elevated expression of endothelin 2 in lung tissues of asthmatic rats after exposed to cigarette smoke and its mechanism]

Objective To study the effect of cigarette smoke exposure on the expression of endothelin 2 (ET-2) in bronchial epithelium of asthmatic rats. Methods Asthma models were established through intraperitoneal injection of 1 mL chicken ovalbumin (OVA)/Al(OH)3 mixture (asthma model group, n=6); based on the asthma models, exposure to smoking gas lasted four weeks with 10 cigarettes per day (smoke-exposed asthma group, n=6); based on the smoke-exposed asthma models, the rats were treated with intraperitoneal injection of dexamethasone 2 mg/(kg.d), intragastric administration of ET receptor inhibitor bosentan 100 mg/(kg.d) and combined use, respectively named dexamethasone treated group, bosentan treated group, and dexamethasone-bosentan treated group, 6 rats in every group. What's more, other 6 rats were only subjected to intraperitoneal injection of 1 mL normal saline as normal controls; in addition to the injection of saline, cigarette smoke control group (n=6) was set up by the exposure to smoking gas for four weeks with 10 cigarettes per day. Bronchoalveolar lavage fluid (BALF) was collected from the upper lobe of the left lung for cell counting and classification. Pathological changes of the right upper lung lobe tissues were observed by HE staining. In other lung tissues, the expression of JNK1/2 was detected by Western blotting; ET-2 was tested by Western blotting and immunohistochemistry; thiobarbituric acid reactive substances (TBARS) assay and trace enzyme standard method were used to measure malondialdehyde (MDA) and glutathione (GSH), respectively. Results Compared with normal control group, the number of airway inflammation cells increased in the BALF, and the expressions of ET-2, JNK1/2, MDA and GSH increased in the lung tissues of cigarette smoke control group, asthma model group and cigarette smoke-exposed asthma group. Compared with cigarette smoke-exposed asthma group, the number of airway inflammation cells decreased in the BALF, and the expressions of ET-2, JNK1/2, MDA and GSH decreased in the lung tissues of the dexamethasone treated group, bosentan treated group, and dexamethasone-bosentan treated group. Airway inflammation was attenuated and the staining intensity of ET-2 in the lung tissue was reduced in the dexamethasone treated group, bosentan treated group, and dexamethasone-bosentan treated group, which were more obvious in the dexamethasone-bosentan treated group. Conclusion Cigarette smoke exposure obviously aggravates airway inflammation in asthmatic rats, and bosentan can effectively alleviate the airway inflammation. The mechanism of the inflammation may be related to ET-2 and JNK1/2 signaling pathway.

Targeting endothelin receptor signalling overcomes heterogeneity driven therapy failure

Approaches to prolong responses to BRAF targeting drugs in melanoma patients are challenged by phenotype heterogeneity. Melanomas of a "MITF-high" phenotype usually respond well to BRAF inhibitor therapy, but these melanomas also contain subpopulations of the de novo resistance "AXL-high" phenotype. > 50% of melanomas progress with enriched "AXL-high" populations, and because AXL is linked to de-differentiation and invasiveness avoiding an "AXL-high relapse" is desirable. We discovered that phenotype heterogeneity is supported during the response phase of BRAF inhibitor therapy due to MITF-induced expression of endothelin 1 (EDN1). EDN1 expression is enhanced in tumours of patients on treatment and confers drug resistance through ERK re-activation in a paracrine manner. Most importantly, EDN1 not only supports MITF-high populations through the endothelin receptor B (EDNRB), but also AXL-high populations through EDNRA, making it a master regulator of phenotype heterogeneity. Endothelin receptor antagonists suppress AXL-high-expressing cells and sensitize to BRAF inhibition, suggesting that targeting EDN1 signalling could improve BRAF inhibitor responses without selecting for AXL-high cells.

Improvement of peripheral artery disease with Sildenafil and Bosentan combined therapy in a patient with limited cutaneous systemic sclerosis: A case report

RATIONALE

Sildenafil, a phosphodiesterase-5-inhibitor and Bosentan, an endothelin-1-receptor antagonist combined therapy could have beneficial effect in systemic sclerosis (SSc) patients with peripheral artery disease.

PATIENT CONCERNS

We report a case of a 48-year-old Black woman, who developed severe left limb claudication and walking limitation following a left femoropopliteal bypass occlusion in 2014. She was a heavy smoker and had a history of right middle cerebral artery ischemic stroke and bilateral Raynaud phenomenon.

DIAGNOSES

According to the American College of Rheumatology/European League Against Rheumatism-2013 criteria, diagnosis of limited cutaneous SSc was retained with macrovascular lesions. She was referred for investigation of left limb claudication on treadmill using transcutaneous oxygen pressure measurement during exercise to argue for the vascular origin of the walking impairment. She had a severe left limb ischemia and the maximum walking distance (MWD) she reached was 118 m in March 2015 despite the medical optimal treatment and walking rehabilitation.

INTERVENTIONS

Sildenafil, 20 mg tid, was introduced due to active digital ulcers. In July 2015, the MWD increased to 288 m, then to 452 m in December 2015. Adding Bosentan to Sildenafil to prevent recurrent digital ulcers resulted in an MWD of 1576 m.

OUTCOMES

Recently, the patient is treated with the combined therapy. She has no more pain during walking and his quality of life has improved.

LESSONS

Sildenafil and Bosentan combined therapy was associated in our case with an improvement of MWD without adverse effect. Further clinical trials are necessary to confirm our original observation.

Dual endothelin receptor antagonists contrast the effects induced by endothelin-1 on cultured human microvascular endothelial cells

OBJECTIVES

To evaluate the ability of dual endothelin (ET) receptor antagonists (ETA/ETB -ETA/BRAs) to contrast the ET-1-induced effects on cultured human microvascular endothelial cells (HMVECs).

METHODS

Some cultured HMVECs were untreated, or treated with ET-1 (100nM) or transforming growth factor β1 (TGFβ1, 10ng/mL) alone for 6 days, in order to induce the endothelial-to-mesenchymal transition (EndoMT). Other cultured HMVECs were pre-treated for 1hr with ETA/BRAs bosentan (10μM) or macitentan (1μM, 10μM) before the stimulation with ET-1 for 6 days. At the end of treatments, a mechanical injury was induced to cultured HMVECs (by scratching the cell monolayer with a sterile tip), and then the cell ability to re-fill the damaged area was determined after 24hrs. EndoMT phenotype markers and monocyte chemoattractant protein-1 (MCP-1) were evaluated by qRT-PCR and Western blotting. Statistical analysis was performed using Mann-Whitney-U non-parametric test.

RESULTS

Both ET-1 and TGFβ1 induced EndoMT and the MCP-1 over-expression in cultured HMVECs, as well as reduced the process of endothelial cell damage repair. Pre-treatment with ETA/BRAs let cultured HMVECs to significantly restore the in vitro damage of the cell monolayer and antagonised the EndoMT process as well as the MCP-1 over-expression (range p<0.05 - p<0.001). Conversely, untreated or TGFβ1-treated HMVECs were found unaffected by the ETA/BRAs treatments.

CONCLUSIONS

The treatment with dual ETA/BRAs seems to partially restore the altered cell function induced by ET-1 in cultured endothelial cells, and might justify their therapeutic efficiency in clinical conditions characterised by increased concentrations of ET-1.

Treatment of Persistent Pulmonary Hypertension of the Newborn: Use of Pulmonary Vasodilators in Term Neonates

Persistent pulmonary hypertension of the newborn (PPHN) represents a challenging condition associated with significant morbidity. A successful transition from intrauterine to extrauterine life is contingent on adequate pulmonary vasodilation. Several pathophysiologies contribute to the failure of this cascade and may result in life-threatening hypoxia and acidosis in the newborn. Management includes optimal respiratory support, adequate sedation and analgesia, and support of vascular tone and cardiac function. Pulmonary vasodilation has the potential to overcome the cycle of hypoxia and acidosis, improving outcome in these infants. Oxygen and inhaled nitric oxide represent the foundation of therapy. Tertiary pulmonary vasodilators represent a greater challenge, selecting between therapies that include prostanoids, sildenafil, and milrinone. Variable levels of evidence exist for each agent. Thorough review of available data informing efficacy and adverse effects contributes to the development of an informed approach to neonates with refractory PPHN.

Assessment of serum endothelin-1 levels in rat appendicitis model and the effects of bosentan

OBJECTIVE

In this study, the diagnostic value of serum endothelin-1 (ET-1) levels and the therapeutic effects of bosentan have been investigated in an experimental appendicitis rat model.

MATERIALS AND METHODS

Twenty-one male Sprague-Dawley rats were chosen for the study. The rats were allocated into three groups as follows: Group 1 (control, n = 7), Group 2 (appendicitis, n = 7), and Group 3 (bosentan treatment, n = 7). At the 6th hour of the experiment, Groups 1 and 2 received 2 ml saline, and group 3 received 30 mg/kg bosentan intraperitoneally. At the 24th postoperative hour, all rats were sacrificed and evaluated histopathologically to score the severity of appendicitis. The plasma malondialdehyde, reduced and total glutathione levels, serum, and appendiceal tissue ET-1 levels were evaluated.

RESULTS

In this study, we found that the ET-1 levels were significantly increased with appendicitis (p = 0.018). The administration of bosentan can statistically significantly both decrease the histopathologic injury in the inflamed appendix and increase the serum total glutathione levels (p = 0.002).

CONCLUSIONS

The increase in plasma ET-1 levels may have a diagnostic value of acute appendicitis. We believe that manifestations that occur during the acute phase of appendicitis may be reduced with the administration of bosentan, which may also help prevent complications.

A comparison of echocardiographic variables of right ventricular function with exercise capacity after bosentan treatment in patients with pulmonary arterial hypertension: Results from a multicenter, prospective, cohort study

PURPOSE

Bosentan reduces pulmonary arterial pressure and improves exercise capacity in patients with pulmonary arterial hypertension (PAH). However, there are limited data regarding the extent to which the changes in echocardiographic variables reflect improvements in exercise capacity. We aimed to assess the improvement of echocardiographic variables and exercise capacity after 6 months of bosentan treatment for PAH.

METHODS

We performed a prospective study from June 2012 to June 2015 in seven participating medical centers. Echocardiography, including tissue Doppler imaging (TDI) and the 6-minute walk test distance (6MWD), was performed at baseline and after 6 months of bosentan treatment.

RESULTS

We analyzed 19 patients with PAH: seven with congenital shunt, six with collagen vascular disease, and six with idiopathic PAH. After bosentan treatment, mean 6MWD increased by 50 meters. Right ventricle (RV) systolic pressure, tricuspid annular plane systolic excursion, myocardial performance index (MPI) derived from TDI (MPI-TDI) of RV and left ventricle (LV), RV fractional area change, and RV ejection fraction were significantly improved. In particular, the magnitude of RV and LV MPI-TDI showed good correlation with changes in the 6MWD.

CONCLUSIONS

The magnitude of RV and LV MPI-TDI was strongly associated with improvements in exercise capacity. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:28-34, 2017.

Alternatively Activated (M2) Macrophage Phenotype Is Inducible by Endothelin-1 in Cultured Human Macrophages

Background

Alternatively activated (M2) macrophages are phenotypically characterized by the expression of specific markers, mainly macrophage scavenger receptors (CD204 and CD163) and mannose receptor-1 (CD206), and participate in the fibrotic process by over-producing pro-fibrotic molecules, such as transforming growth factor-beta1 (TGFbeta1) and metalloproteinase (MMP)-9. Endothelin-1 (ET-1) is implicated in the fibrotic process, exerting its pro-fibrotic effects through the interaction with its receptors (ET_A and ET_B). The study investigated the possible role of ET-1 in inducing the transition from cultured human macrophages into M2 cells.

Methods

Cultured human monocytes (THP-1 cell line) were activated into macrophages (M0 macrophages) with phorbol myristate acetate and subsequently maintained in growth medium (M0-controls) or treated with either ET-1 (100nM) or interleukin-4 (IL-4, 10ng/mL, M2 inducer) for 72 hours. Similarly, primary cultures of human peripheral blood monocyte (PBM)-derived macrophages obtained from healthy subjects, were maintained in growth medium (untreated cells) or treated with ET-1 or IL-4 for 6 days. Both M0 and PBM-derived macrophages were pre-treated with ET receptor antagonist (ET_A/BRA, bosentan 10^-5M) for 1 hour before ET-1 stimulation. Protein and gene expression of CD204, CD206, CD163, TGFbeta1 were analysed by immunocytochemistry, Western blotting and quantitative real time polymerase chain reaction (qRT-PCR). Gene expression of interleukin(IL)-10 and macrophage derived chemokine (CCL-22) was evaluated by qRT-PCR. MMP-9 production was investigated by gel zymography.

Results

ET-1 significantly increased the expression of M2 phenotype markers CD204, CD206, CD163, IL-10 and CCL-22, and the production of MMP-9 in both cultures of M0 and PBM-derived macrophages compared to M0-controls and untreated cells. In cultured PBM-derived macrophages, ET-1 increased TGFbeta1 protein and gene expression compared to untreated cells. The ET-1-mediated effects were contrasted by ET_A/BRA treatment in both cultured cell types.

Conclusion

ET-1 seems to induce the M2 phenotype in cultured human macrophages, a process apparently contrasted by the action of the ET_A/BRA, suggesting possible clinical implications in those fibrotic diseases characterized by increased ET-1 concentrations, such as systemic sclerosis but also type 2 diabetes.

Efficacy of bosentan in patients with refractory thromboangiitis obliterans (Buerger disease): A case series and review of the literature

The cornerstone of therapy in thromboangiitis obliterans (TAO) is complete abstinence from tobacco. In addition to discontinuation of cigarette smoking, very few pharmacological and surgical options of controversial efficacy are available to date. New therapeutic options with greater efficacy are clearly needed to properly manage these patients.In this preliminary study, we assessed the effectiveness and safety of bosentan in a case series of 8 adults with TAO and severe ischemic ulceronecrotic lesions who were treated with bosentan after inadequate response to platelet inhibitors, vasodilators, and intravenous alprostadil. Additionally, we reviewed 18 well-documented patients with refractory TAO treated with bosentan, which was previously reported (PubMed 1965-2015). These 26 patients formed the basis of our present analysis. All were current smokers.The median duration of bosentan treatment (SD) was 4.5 ± 4 months (range 3-16). Eleven patients (42%) were unable to completely abstain from smoking during their follow-up. With bosentan treatment, no new ischemic lesions were observed in the target extremities. A complete therapeutic response was achieved in 80% of patients, whereas a partial response was observed in 12%. Two patients (8%) ultimately required amputation despite treatment.After discontinuation of bosentan, patients were followed for a median of 20 ± 14 months (range 3-60). Two patients whose trophic lesions had healed relapsed.When comparing patients who gave up smoking with those who were unable to completely abstain from smoking during follow-up, no significant differences were found in efficacy outcomes. Four patients (15%) developed adverse events, requiring bosentan discontinuation in 1 case.These preliminary data suggest that bosentan may be considered a therapeutic option for treatment of cases of severe TAO refractory to conventional treatment, and merit further evaluation in larger controlled, randomized clinical studies.

[Digital ulcers in systemic sclerosis : A retrospective heath service study analysing treatment with bosentan and other vasoactive therapies]

BACKGROUND

Digital ulcers (DU) affect up to 60 % of patients with systemic sclerosis (SSc) and have a considerable impact on quality of life and morbidity. It is unclear to what extent authorised medicines are used, and if therapy guidelines are implemented in everyday practice.

METHOD

This retrospective health care study examined current standards of treatment for therapy and prevention of SSc-associated DU in an online survey with 83 physicians. Additionally, data from 161 case studies of SSc patients with DU were analysed, and the effect of DU treatment on the course of the disease determined.

RESULTS

For treatment and prevention of active DU, physicians predominantly indicated topical therapies, calcium channel blockers, iloprost and endothelin receptor antagonists. According to the case studies, 90 % of episodes with acute DU were treated with bosentan and iloprost in mono- or combination therapy. Preventive treatment was only administered during 50 % of episodes without DU, even after three or more phases with active DU. For the prevention of new DU, bosentan was used in mono- or combination therapy in 57 % of episodes without DU. Bosentan therapy during prevention shortened the following acute phase by 32 %. Additionally, continuous treatment with bosentan in acute and prevention phases reduced the duration of the following acute phase and increased the time to onset of new DU by 16 %. Moreover, bosentan stabilised the number of new DU.

CONCLUSION

In summary, these data confirm the efficacy of bosentan in preventing new DU when used in DU-free episodes and possibly also in phases of acute DU. Therapy recommendations for the treatment of DU are currently not fully implemented. In the future, even more attention should be paid to DU therapy.

Endothelin receptor antagonists for persistent pulmonary hypertension in term and late preterm infants

BACKGROUND

Endothelin, a powerful vasoconstrictor, is one of the mediators in the causation of persistent pulmonary hypertension of the newborn (PPHN). Theoretically, endothelin receptor antagonists (ETRA) have the potential to improve the outcomes of infants with PPHN.

OBJECTIVES

To assess the efficacy and safety of ETRA in the treatment of PPHN in full-term, post-term and late preterm infants.To assess the efficacy and safety of selective ETRAs (which block only the ETA receptors) and non-selective ETRAs (which block both ETA and ETB receptors) separately.

SEARCH METHODS

CENTRAL (Cochrane Central Register of Controlled Trials), MEDLINE, EMBASE and CINAHL databases were searched until December 2015.

SELECTION CRITERIA

Randomised, cluster-randomised or quasi-randomised controlled trials were eligible.

DATA COLLECTION AND ANALYSIS

Two review authors independently searched the literature, selected the studies, assessed the risk of bias and extracted the data. A fixed-effect model was used for meta-analysis. We used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to assess the quality of evidence.

MAIN RESULTS

Two randomised controlled trials of ETRA met the inclusion criteria. Both studies utilized oral Bosentan. The first study was done in a setting where inhaled nitric oxide (iNO) therapy was not available. Forty-seven infants (≥ 34 weeks' gestation) were randomised to receive either Bosentan or placebo. The second study was a multicentre study where iNO therapy was the standard of care for PPHN. Twenty-one infants were randomised to receive either 'iNO plus Bosentan' or 'iNO plus placebo'.In the first study, there was no significant difference in the incidence of death before hospital discharge between the Bosentan and placebo groups (1/23 vs 3/14; RR 0.20, 95% CI 0.02 to 1.77; RD -0.17, 95% CI -0.40 to 0.06). A higher proportion of infants in the Bosentan group showed improvement in oxygenation index (OI) at the end of therapy (21/24 vs 3/15; RR 4.38, 95% CI 1.57 to 12.17; RD 0.68, 95% CI 0.43 to 0.92; number needed to treat for a beneficial outcome (NNTB) 1.5). The duration of mechanical ventilation was lower in the Bosentan group (4.3 ± 0.9 vs 11.5 ± 0.6 days; MD -7.20, 95% CI -7.64 to -6.76). There was no significant difference in adverse neurological outcomes at six months (0/23 vs 4/14; RR 0.07, 95% CI 0.00 to 1.20; RD -0.29, 95% CI -0.52 to -0.05). The study suffered from a high risk of attrition bias since 8/23 infants in the placebo group were excluded from various analyses. Since the protocol for the study could not be accessed, the study suffered from unclear risk of reporting bias.In the second study, there was no significant difference in the incidence of treatment failure needing extracorporeal membrane oxygenation (ECMO) between the 'iNO plus Bosentan' vs 'iNO plus placebo' groups (1/13 vs 0/8; RR 1.93, 95% CI 0.09 to 42.35; RD 0.08, 95% CI -0.14 to 0.30). There was no significant difference in the median time to wean from iNO ('iNO plus Bosentan': 3.7 days (95% CI 1.17 to 6.95); 'iNO plus placebo': 2.9 days (95% CI 1.26 to 4.23); P = 0.34). There were no significant differences in the OI 0, 3, 5, 12, 24, 48 and 72 hours of treatment between the groups. There were no significant differences in the time to complete weaning from mechanical ventilation (median 10.8 days (CI 3.21 to 12.21) versus 8.6 days (CI 3.71 to 9.66); P = 0.24). The study had unequal distribution to the Bosentan group (N = 13) and the placebo group (N = 8). The methods used for generating random sequence numbers and allocation concealment were unclear, resulting in unclear risk of selection bias.Both studies reported that Bosentan was well tolerated and no major adverse effects were noted. Data from the two studies was not pooled given the heterogenous nature of the clinical settings and the modalities used for the treatment of PPHN.Overall, the quality of evidence was considered low, given the small sample size of the included studies, the numerical imbalance between the groups due to randomisation and attrition, and unclear risk of bias on some of the important domains.

AUTHORS' CONCLUSIONS

There is inadequate evidence to support the use of ETRAs either as stand-alone therapy or as adjuvant to inhaled nitric oxide in PPHN. Adequately powered RCTs are needed.

Effect of endothelin-1 and endothelin receptor blockade on the release of microparticles

BACKGROUND

Increased levels of endothelial cell microparticles (EMP) are known to reflect endothelial dysfunction (ED). In diabetes mellitus type 2 (T2DM), the expression of endothelin (ET)-1 is increased. As treatment with an ET-1 antagonist significantly inhibited atherosclerosis in animal models, we sought to investigate whether treatment with ET-1 antagonists affects EMP levels in vitro and in vivo in patients with T2DM.

MATERIALS AND METHODS

In vitro study: Human umbilical vein endothelial cells (HUVEC) were stimulated with ET-1 alone and ET-1 in combination with a dual ET-A and ET-B endothelin receptor blocker. In vivo study: Patients with T2DM were randomized to treatment with the ET receptor antagonist bosentan or placebo. After 4 weeks, the patients were re-examined and blood samples were obtained. EMP counts in supernatants and plasma samples were determined using flow cytometry.

RESULTS

In vitro study: In supernatants of ET-1-stimulated HUVECs, the increased release of EMP was reduced significantly by co-incubation with an ET-1 receptor antagonist (e.g. CD31+/CD42b-EMP decreased from 37·1% ± 2·8 to 31·5% ± 2·8 SEM, P = 0·0078). In vivo study: No changes in EMP levels in blood samples of patients with T2DM were found after 4 weeks of bosentan treatment (n = 36, P = ns).

CONCLUSIONS

Our in vitro results suggest that ET-1 stimulates the release of EMP from HUVECs via a receptor-dependent mechanism. Co-incubation with an endothelin receptor blocker abolished ET-1-dependent EMP release. However, treatment with bosentan for 4 weeks failed to alter EMP levels in patients with T2DM. Other factors seem to have influenced EMP release in patients with T2DM independent of ET-1 receptor-mediated mechanisms.

Bosentan use in systemic lupus erythematosus patients with pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) in patients with systemic lupus erythematosus (SLE) is uncommon but is associated with poor survival. This study aimed to examine the long-term effects of bosentan, a dual endothelin-1 receptor antagonist, on symptomatology, haemodynamics and quality of life measures in SLE patients with symptomatic PAH. Four local patients had been followed up prospectively with pre-defined protocol during 12-months of bosentan treatment. Six minute walk distance (6MWD), NYHA functional class, Borg Dyspnoea Index (BDI) and SF-36 were measured at 0, 3, 6, 9 and 12 months. Systolic pulmonary arterial pressure (PAP) was measured by transthoracic echocardiography at zero, six and 12 months. Clinical parameters were analysed, pooling data from other SLE patients reported in the literature ( n = 4). Bosentan was found to result in significant improvement in 6MWD compared to baseline [+24.8 m, +26.2 m, +54 m and +62.7 m at three ( P = 0.001), six ( P = 0.001), nine ( P = 0.24) and 12 ( P = 0.01) months respectively]. A differential effect was found with greater response in patients with lower exercise capacity. This was accompanied by decrease in NYHA functional class, BDI, transient or sustained drop in systolic PAP and mild improvement in SF-36 domains including mental health, vitality, social function and general health. Significantly deranged liver function was found in one patient. Lupus (2007) 16, 279—285.

THE COMPARISON OF THE STABILITY INDICATING TWO HPLC METHODS AND THEIR APPLICATION FOR THE DETERMINATION OF BOSENTAN IN COATED TABLETS

Due to the raising requirements of drug quality, there is an increasing need for fast liquid separations of pharmaceutical substances with high efficiency and good resolution. The ultra-high pressure liquid chromatography (UHPLC) has been considered to meet this challenge. However, it was found that this fast method has also serious disadvantages. The range of applications of the UHPLC in the analysis of pharmaceutical substances and dosage forms is currently extensively discussed. In this study we investigated the consequences of the shortening of the analysis time of the liquid chromatographic method. Bosentan, a non-peptide antagonist of human endothelin receptors, was chosen as an example in this study, due to its therapeutic importance and lack of the reported analytical methods of the drug product. Two high-performance, reversed phase liquid chromatography methods with UV detection at 220 nm were developed for this purpose. Both methods were validated and the resulting performance characteristics were compared. The first separation (method A) was achieved on Kinetex column, (2.6 μ C18 1OOA, 150 x 4.6 mm), the second-fast (method B) employed Kinetex column, (1.7 μ XB-C18 100A 50 x 3.0 mm). Both methods were performed with a buffered mobile phase containing 0.1% of triethylamine in water brought to the pH 2.5 with phosphoric acid and methanol as the solvent A and acetonitrile as the solvent B. Gradient program was used and flow rate of 0.8 mL/min and 0.4 mL/min, for the methods A and B, respectively. The methods were validated according to the ICH guidelines for specificity, precision on the specified and LOQ limits, intermediate precision, accuracy, linearity (correlation co-efficient =0.999) and robustness. The robustness was confirned using four factors: the mobile phase pH, the flow rate of the mobile phase, column temperature and the second column of the same kind. The limits of detection and quantification were established as 0.0132 and 0.1505 μg/mL for methods A and B, respectively. Both validated methods complied with the acceptance criteria. The method B was 3.5 times faster than the method A, but the method A showed much better sensitivity. The resolution between compound B and bosentan was 3.39 and 1.75 for methods A and B, respectively. The lower sensitivity limits the use of Method B, especially in the analyses at low levels of active substances (e.g., bioanalysis, validation of the cleaning procedures) and makes method A more suitable for this purpose.

The Role of Endothelin System in Renal Structure and Function during the Postnatal Development of the Rat Kidney

Renal development in rodents, unlike in humans, continues during early postnatal period. We aimed to evaluate whether the pharmacological inhibition of Endothelin system during this period affects renal development, both at structural and functional level in male and female rats. Newborn rats were treated orally from postnatal day 1 to 20 with vehicle or bosentan (Actelion, 20 mg/kg/day), a dual endothelin receptor antagonist (ERA). The animals were divided in 4 groups: control males, control females, ERA males and ERA females. At day 21, we evaluated renal function, determined the glomerular number by a maceration method and by morphometric analysis and evaluated possible structural renal alterations by three methods: 〈alpha〉-Smooth muscle actin (α-SMA) immunohistochemistry, Masson's trichrome and Sirius red staining. The pharmacological inhibition of Endothelin system with a dual ERA during the early postnatal period of the rat did not leads to renal damage in the kidneys of male and female rats. However, ERA administration decreased the number of glomeruli, the juxtamedullary filtration surface area and the glomerular filtration rate and increased the proteinuria. These effects could predispose to hypertension or renal diseases in the adulthood. On the other hand, these effects were more pronounced in male rats, suggesting that there are sex differences that could be greater later in life. These results provide evidence that Endothelin has an important role in rat renal postnatal development. However these results do not imply that the same could happen in humans, since human renal development is complete at birth.

[Pharmacological therapy of age-related macular degeneration based on etiopathogenesis]

It is of great therapeutic significance that disordered function of the vascular endothelium which supply the affected ocular structures plays a major role in the pathogenesis and development of age-related macular degeneration. Chronic inflammation is closely linked to diseases associated with endothelial dysfunction, and age-related macular degeneration is accompanied by a general inflammatory response. According to current concept, age-related macular degeneration is a local manifestation of systemic vascular disease. This recognition could have therapeutic implications because restoration of endothelial dysfunction can restabilize the condition of chronic vascular disease including age-related macular degeneration as well. Restoration of endothelial dysfunction by pharmaacological or non pharmacological interventions may prevent the development or improve endothelial dysfunction, which result in prevention or improvement of age related macular degeneration as well. Medicines including inhibitors of the renin-angiotensin system (converting enzyme inhibitors, angiotensin-receptor blockers and renin inhibitors), statins, acetylsalicylic acid, trimetazidin, third generation beta-blockers, peroxisome proliferator-activated receptor gamma agonists, folate, vitamin D, melatonin, advanced glycation end-product crosslink breaker alagebrium, endothelin-receptor antagonist bosentan, coenzyme Q10; "causal" antioxidant vitamins, N-acetyl-cysteine, resveratrol, L-arginine, serotonin receptor agonists, tumor necrosis factor-alpha blockers, specific inhibitor of the complement alternative pathway, curcumin and doxycyclin all have beneficial effects on endothelial dysfunction. Restoration of endothelial dysfunction can restabilize chronic vascular disease including age-related macular degeneration as well. Considering that the human vascular system is consubstantial, medicines listed above should be given to patients (1) who have no macular degeneration but have risk factors for the disease and are older than 50 years; (2) who have been diagnosed with unilateral age-related macular degeneration in order to prevent damage of the contralateral eye; (3) who have bilateral age-related macular degeneration in order to avert deterioration and in the hope of a potential improvement. However, randomised prospective clinical trials are still needed to elucidate the potential role of these drug treatments in the prevention and treatment of age-related macular degeneration.

Severe pulmonary arterial hypertension in an adult patient with total anomalous pulmonary venous connection operated in infancy

The goal of total anomalous pulmonary venous connection repair is to obtain an unobstructed communication between the pulmonary veins and the left atrium and removing intracardiac shunting. However, pulmonary venous obstruction orstenosis may be seen in 5-10% of patients, is usually evident in the first 6 months following surgery and may lead to pulmonary congestion, pulmonary arterial hypertension, and late mortality. In such cases, early intervention may be indicated before irreversible secondary changes occur. We present the case and the therapeutic approach of an adolescent patient with total anomalous pulmonary venous drainage to the superior vena cava operated in infancy who developed pulmonary venous obstruction and secondary severe pulmonary arterial hypertension.

Surgical Closure of Atrial Septal Defect with High Pulmonary Vascular Resistance--A Case Report

We have reported a case of successful pericardial patch closure of atrial septal defect with high pulmonary vascular resistance in a 32 years aged male. Diagnosis was confirmed by Doppler Echocardiography, Cardiac catheterization and lung biopsy. Before starting (orally) bosentan pulmonary arterial pressure was 105 mm Hg and pulmonary vascular resistance was 8 wood's unit. Bosentan was started at a dosage of 125 mg per day (62.5 mg twice a day) for 4 months before operation in this case. Just day before operation pulmonary arterial pressure was 87 mm Hg. Bosentan lowered pulmonary arterial pressure and reversed remodeling of pulmonary arteries and allowed surgical correction. During the post operative course, partial pressure of oxygen was significantly decreased and bilateral radiolucent opacity was present in lower zone of both lungs. All these were managed successfully in postoperative period. This case report has demonstrated that surgical correction of an atrial septal defect is feasible but requires long time pre and post operative treatment with pulmonary vasodilators.

Postotic and preotic cranial neural crest cells differently contribute to thyroid development

Thyroid development and formation vary among species, but in most species the thyroid morphogenesis consists of five stages: specification, budding, descent, bilobation and folliculogenesis. The detailed mechanisms of these stages have not been fully clarified. During early development, the cranial neural crest (CNC) contributes to the thyroid gland. The removal of the postotic CNC (corresponding to rhombomeres 6, 7 and 8, also known as the cardiac neural crest) results in abnormalities of the cardiovascular system, thymus, parathyroid glands, and thyroid gland. To investigate the influence of the CNC on thyroid bilobation process, we divided the CNC into two regions, the postotic CNC and the preotic CNC (from the mesencephalon to rhombomere 5) regions and examined. We found that preotic CNC-ablated embryos had a unilateral thyroid lobe, and confirmed the presence of a single lobe or the absence of lobes in postotic CNC-ablated chick embryos. The thyroid anlage in each region-ablated embryos was of a normal size at the descent stage, but at a later stage, the thyroid in preotic CNC-ablated embryos was of a normal size, conflicting with a previous report in which the thyroid was reduced in size in the postotic CNC-ablated embryos. The postotic CNC cells differentiated into connective tissues of the thyroid in quail-to-chick chimeras. In contrast, the preotic CNC cells did not differentiate into connective tissues of the thyroid. We found that preotic CNC cells encompassed the thyroid anlage from the specification stage to the descent stage. Finally, we found that endothelin-1 and endothelin type A receptor-knockout mice and bosentan (endothelin receptor antagonist)-treated chick embryos showed bilobation anomalies that included single-lobe formation. Therefore, not only the postotic CNC, but also the preotic CNC plays an important role in thyroid morphogenesis.

The lung endothelin system: a potent therapeutic target with bosentan for the amelioration of lung alterations in a rat model of diabetes mellitus

PURPOSE

The aim of this study is to show the effect of a new mechanism on endothelin (ET) receptors in the physiopathology of diabetes-related pulmonary injury. We tested the hypothesis that dual ET-1 receptor antagonism via bosentan can reverse diabetes-induced lung injury.

METHODS

The rats (24 male) were separated into four groups: group 1 (HEALTHY): Control group; group 2 (DM): Streptozotocin 60 mg/kg (i.p.); group 3 (DM + BOS-1): Diabetes + bosentan 50 mg/kg per-os; group 4 (DM + BOS-2): Diabetes + bosentan 100 mg/kg per-os. The bosentan treatment was initiated immediately after the onset of STZ-induced diabetes and continued for 6 weeks.

RESULTS

In the treatment group, SOD activity was significantly increased, although GSH and MDA levels and TNF-α and TGF-β gene expression were decreased. Bosentan 50 mg/kg and bosentan 100 mg/kg showed a significantly down-regulatory effect on ET-1, ET-A, and ET-B mRNA expression.

CONCLUSIONS

In conclusion, increased endothelin levels in the lung associated with diabetes may be one cause of endothelial dysfunction, cytokine increase, and oxidant/antioxidant imbalance in the pathogenesis of complications that may develop during diabetes. With its multiple effects, bosentan therapy may be an effective option against complications that may develop in association with diabetes.

What is the role of bosentan in healing of femur fractures in a rat model?

The purpose of this study was to examine the effects bosentan (which is a strong vasoconstrictor) on bone fracture pathophysiology, and investigate the roles of the nonselective endothelin 1 receptor blocker bosentan on the bone fractures formed in rats through radiographic, histopathologic, and immunohistochemical methods. The rats were divided into three groups (six rats in each group): a femoral fracture control group, a femoral fracture plus bosentan at 50 mg/kg group, and a femoral fracture plus bosentan at 100 mg/kg group. The femoral fracture model was established by transversely cutting the femur at the midsection. After manual reduction, the fractured femur was fixed with intramedullary Kirschner wires. The radiographic healing scores of the bosentan 100 and 50 mg/kg groups were significantly better that those of the fracture control group. The fracture callus percent of new bone in the bosentan 100 mg/kg group was significantly greater than that in the control group. Also, semiquantitative analysis showed higher positive vascular endothelial growth factor and osteocalcin staining and lower positive endothelin receptor type A staining in the treatment groups than in the control group. Bosentan treatment also decreased tissue endothelin 1 expression relative to that in the fracture control group. As a result of our study, the protective effect of bosentan was shown in experimental femoral fracture healing in rats by radiographic, histopathologic, and molecular analyses.

Bosentan, a mixed endothelin receptor antagonist, inhibits superoxide anion-induced pain and inflammation in mice

Bosentan is a mixed endothelin receptor antagonist widely used to treat patients with pulmonary arterial hypertension, and the emerging literature suggests bosentan as a potent anti-inflammatory drug. Superoxide anion is produced in large amounts during inflammation, stimulates cytokine production, and thus contributes to inflammation and pain. However, it remains to be determined whether endothelin contributes to the inflammatory response triggered by the superoxide anion. The present study investigated the effects of bosentan in a mouse model of inflammation and pain induced by potassium superoxide, a superoxide anion donor. Male Swiss mice were treated with bosentan (10-100 mg/kg) by oral gavage, 1 h before potassium superoxide injection, and the inflammatory response was evaluated locally and at spinal cord (L4-L6) levels. Bosentan (100 mg/kg) inhibited superoxide anion-induced mechanical and thermal hyperalgesia, overt pain-like behavior (abdominal writhings, paw flinching, and licking), paw edema, myeloperoxidase activity (neutrophil marker) in the paw skin, and leukocyte recruitment in the peritoneal cavity. Bosentan also inhibited superoxide anion-induced interleukin-1 beta (IL-1β) and tumor necrosis factor alpha (TNF-α) production, while it enhanced IL-10 production in the paw skin and spinal cord. Bosentan inhibited the reduction of antioxidant capacity (reduced glutathione, ferric reducing antioxidant power, and ABTS radical scavenging ability) induced by the superoxide anion. Finally, we demonstrated that intraplantar injection of potassium superoxide induces the mRNA expression of prepro-endothelin-1 in the paw skin and spinal cord. In conclusion, our results demonstrated that superoxide anion-induced inflammation, pain, cytokine production, and oxidative stress depend on endothelin; therefore, these responses are amenable to bosentan treatment.

Bosentan blocks the antiangiogenic effects of sera from systemic sclerosis patients: an in vitro study

OBJECTIVES

In systemic sclerosis (SSc), clinical evidence has shown that Bosentan may foster the regeneration of the peripheral microcirculatory network. The aim of this study was to verify in vitro the influence of Bosentan on the angiogenic performance of dermal microvascular endothelial cells (MVECs) and its possible capacity to counteract the antiangiogenic effects of SSc sera.

METHODS

Healthy dermal MVECs were challenged with Bosentan at different concentrations (0.1 μM, 1 μM, 10 μM) or with sera from patients with diffuse cutaneous SSc (n=8) and healthy subjects (n=8), alone or in combination with Bosentan (10 μM). Cell viability and chemoinvasion were determined by WST-1 and Boyden chamber assays, respectively. Angiogenesis was evaluated by capillary morphogenesis on Matrigel.

RESULTS

Challenge of dermal MVECs with SSc sera induced a significant reduction in angiogenesis (p<0.005 vs. basal condition; p<0.001 vs. healthy sera). The addition of Bosentan could significantly restore angiogenesis in the presence of SSc sera (p<0.01 vs. SSc sera alone). Healthy sera promoted cell viability which was, instead, significantly reduced with SSc sera (p<0.005 vs. healthy sera). The addition of Bosentan to MVECs challenged with SSc sera significantly increased cell viability (p<0.005 vs. SSc sera alone), reaching levels similar to MVECs treated with healthy sera. Co-incubation of MVECs with Bosentan and SSc sera significantly increased chemoinvasion (p<0.005 vs. SSc sera alone) which was inhibited by SSc sera (<0.001 vs. healthy sera).

CONCLUSIONS

Bosentan effectively counteracts the antiangiogenic effects of SSc sera on dermal MVECs and fosters the restoration of a proangiogenic environment.

Comparison of angiogenic and proliferative effects of three commonly used agents for pulmonary artery hypertension (sildenafil, iloprost, bosentan): is angiogenesis always beneficial?

OBJECTIVE

Pulmonary artery hypertension (PAH) is devastating disease that has very serious outcomes. Dysregulated angiogenesis is one of the main responsible courses in pathophysiology of disease. Our experimental research intends to find out and compare the angiogenic effects of medications used sildenafil, iloprost, and bosentan in the treatment of PAH.

MATERIALS AND METHODS

This study was performed in Department of Biochemistry and Cancer and Stem Cell Research Laboratory of our institutes between August and October 2014. Angiogenic activity of sildenafil, iloprost, and bosentan were examined in vivo in chick chorioallantoic membrane (CAM) model and in vitro tube formation assay of human umbilical vein endothelial cells (HUVECs). Proliferative activity of these three agents was also determined through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay on HUVECs.

RESULTS

In CAM assay, when compared to the control and drug groups, treatment with sildenafil solutions resulted in a significant dose-dependent increase (budding, sprouting, extravasation) on CAM vessel growth. While there was no significant proliferative effect with iloprost and bosentan, presence of sildenafil caused a statistically significant proliferation on HUVECs following 24 and 48 h incubation (p < 0.05) compared to the control group. Comparing the tube length/area ratio values, there was statistically significant increase in sildenafil group with respect to the other 2 groups (p < 0.05). Iloprost and bosentan did not show a significant effect.

CONCLUSIONS

The results provide evidence that sildenafil but not iloprost and bosentan induces angiogenesis in vitro and in vivo. Dysregulated angiogenesis, as an important pathophysiological part in the progression of PAH, may be triggered by the chronic ingestion of sildenafil in the long treatment period and may cause negative effects.

Multiple compound-related adverse properties contribute to liver injury caused by endothelin receptor antagonists

Drug-induced liver injury has been observed in patients treated with the endothelin receptor antagonists sitaxentan and bosentan, but not following treatment with ambrisentan. The aim of our studies was to assess the possible role of multiple contributory mechanisms in this clinically relevant toxicity. Inhibition of the bile salt export pump (BSEP) and multidrug resistance-associated protein 2 was quantified using membrane vesicle assays. Inhibition of mitochondrial respiration in human liver-derived HuH-7 cells was determined using a Seahorse XF(e96) analyzer. Cytochrome P450 (P450)-independent and P450-mediated cell toxicity was assessed using transfected SV40-T-antigen-immortalized human liver epithelial (THLE) cell lines. Exposure-adjusted assay ratios were calculated by dividing the maximum human drug plasma concentrations by the IC50 or EC50 values obtained in vitro. Covalent binding (CVB) of radiolabeled drugs to human hepatocytes was quantified, and CVB body burdens were calculated by adjusting CVB values for fractional drug turnover in vitro and daily therapeutic dose. Sitaxentan exhibited positive exposure-adjusted signals in all five in vitro assays and a high CVB body burden. Bosentan exhibited a positive exposure-adjusted signal in one assay (BSEP inhibition) and a moderate CVB body burden. Ambrisentan exhibited no positive exposure-adjusted assay signals and a low CVB body burden. These data indicate that multiple mechanisms contribute to the rare, but potentially severe liver injury caused by sitaxentan in humans; provide a plausible rationale for the markedly lower propensity of bosentan to cause liver injury; and highlight the relative safety of ambrisentan.

Bosentan for patients with echocardiographic evidence of pulmonary hypertension due to long-standing rheumatic mitral stenosis

INTRODUCTION

Vasoconstrictive endothelin signaling is not limited to idiopathic pulmonary arterial hypertension, but has also been implicated in pulmonary hypertension due to valvular heart disease. The efficacy and safety of endothelin receptor antagonists in these patients is unknown. We investigated the effects of bosentan in patients with transthoracic echocardiographic (TTE) evidence of pulmonary hypertension due to mitral stenosis associated with rheumatic fever.

METHODS

This was a prospective, single-center, open-label, uncontrolled study of bosentan in outpatients with uncorrected mitral stenosis due to rheumatic fever. The primary endpoint was exercise capacity at six months, as determined by six-minute walking distance (6MWD) and maximal oxygen uptake (VO₂max). Secondary endpoints were the BORG dyspnea index (BDI), echocardiographic left ventricular ejection fraction (LVEF) and pulmonary arterial pressure (PAP), serum pro-brain natriuretic peptide (proBNP), and adverse events at six months.

RESULTS

Ten patients (eight females; mean age 75 years) were enrolled. Bosentan was well tolerated by nine, whereas one withdrew from treatment. By intention-to-treat analysis, bosentan resulted in a marked increase in 6MWD (+32 m, p=0.015), but a significant reduction in VO₂max (-0.45 mL/min/kg, p=0.011). Peak PAP did not change significantly, but mean PAP dropped by 16% (p=0.03) and LVEF increased by 6.5% (p=0.003). Profound reductions were observed in BDI and serum proBNP (-67% and -37%, p=0.002 and p=0.011, respectively). Adverse events included minor reductions in body mass and hematocrit.

CONCLUSION

The results of this pilot study suggest that endothelin receptor antagonism improves the functional status of patients with TTE evidence of pulmonary hypertension due to valvular heart disease. Randomized controlled trials are needed to confirm the results.

[Pregnant woman with pulmonary hypertension]

Pulmonary hypertension is a disease with diverse etiology. According to the New ESC guidelines, pregnancy is contraindicated for a patent with pulmonary hypertension and qualify such patent to class IV NYHA, regardless of the reason of hypertension. Pregnancy is revived for a patient with pulmonary hypertension despite of the fact that recent treatment methods including specific therapy with the endothelin receptor antagonistst (bosentan), phosphodiesterase inhibitors (sildenafil) and prostacyclin analogs (iloprost) were introduced. In the case of coincidence of pregnancy and pulmonary hypertension, patients should be managed in a center with expertise in pulmonary hypertension with all therapeutic options available.