Pulmonary Hypertension in 2021: Part I-Definition, Classification, Pathophysiology, and Presentation

Advances in the potential of nebulized inhalation for the treatment of pulmonary arterial hypertension

Pulmonary hypertension is a pathophysiologic manifestation of a heterogeneous group of diseases, with the main pathophysiologic mechanisms being persistent pulmonary vasoconstriction and irreversible vascular remodeling. The impact significantly affects the prognosis of patients with pulmonary hypertension. If it is not treated and intervened in time, it may lead to right ventricular failure and further endanger the patient's life. Within the past decade or so, nebulized inhalation therapy is considered to have advantages in the treatment of pulmonary hypertension as a safe, limited, and rapid therapy, for example, inhaled vasodilators (prostate analogs, nitroglycerin, carbon monoxide analogs sildenafil, and nitroprusside), inhaled anti-inflammatory and antiproliferative agents (simvastatin, and selatinib), and inhaled peroxides (levocetirizine) have been recognized as emerging therapeutic approaches in the treatment of pulmonary hypertension as emerging therapeutic approaches. Therefore, this article provides a brief review of recent advances in the potential of nebulized inhaled vasodilators, anti-inflammatory and antiproliferative agents, and anti-peroxides for the treatment of pulmonary hypertension, with the aim of providing different therapeutic options for the treatment of pulmonary hypertension, enhancing the quality of survival, alleviating symptoms, and improving the prognosis of patients with this condition.

Portopulmonary hypertension: peculiarities of diagnosis and treatment

Portopulmonary hypertension is defined as the development of pulmonary hypertension secondary to portal one. Its exact prevalence is difficult to determine due to the lack of routine screening in patients with portal hypertension. Hemodynamic changes associated with portal hypertension, including the hyperdynamic state, portosystemic shunts, and splanchnic vasodilation, cause significant disturbances in the pulmonary vasculature and play a key role in the pathogenesis of the disease. Without treatment, portopulmonary hypertension leads to progressive right ventricular failure with a poor prognosis. Although Doppler echocardiography is the best initial screening tool for symptomatic patients and candidates for liver transplant, right heart catheterization remains the gold standard for disease diagnosis. Treatment of patients with portopulmonary hypertension is aimed at improving cardiac function, reducing pulmonary vascular resistance, and optimizing functional capacity. Pulmonary hypertension-specific therapy, which includes prostacyclin and its receptor agonists, endothelin receptor antagonists, phosphodiesterase inhibitors, and guanylate cyclase stimulators, plays a key role in the treatment of patients with portopulmonary hypertension. Small uncontrolled and recent single randomized controlled trials have reported promising results of vasodilator therapy in terms of clinical and hemodynamic improvement in patients, allowing certain patients to undergo liver transplantation. This review discusses the epidemiology, approach to diagnosis and treatment of patients with portopulmonary hypertension. We used MEDLINE database on the PubMed platform and the Cochrane library to search for literature sources using the keywords: portopulmonary hypertension, portal hypertension, pulmonary hypertension, liver cirrhosis, pulmonary complications.

Pulmonary Hypertension and the Risk of 30-Day Postoperative Pulmonary Complications after Gastrointestinal Surgical or Endoscopic Procedures: A Retrospective Propensity Score-Weighted Cohort Analysis

Background: Pulmonary hypertension (PH) patients are at higher risk of postoperative complications. We analyzed the association of PH with 30-day postoperative pulmonary complications (PPCs). Methods: A single-center propensity score overlap weighting (OW) retrospective cohort study was conducted on 164 patients with a mean pulmonary artery pressure (mPAP) of >20 mmHg within 24 months of undergoing elective inpatient abdominal surgery or endoscopic procedures under general anesthesia and a control cohort (N = 1981). The primary outcome was PPCs, and the secondary outcomes were PPC sub-composites, namely respiratory failure (RF), pneumonia (PNA), aspiration pneumonia/pneumonitis (ASP), pulmonary embolism (PE), length of stay (LOS), and 30-day mortality. Results: PPCs were higher in the PH cohort (29.9% vs. 11.2%, p < 0.001). When sub-composites were analyzed, higher rates of RF (19.3% vs. 6.6%, p < 0.001) and PNA (11.2% vs. 5.7%, p = 0.01) were observed. After OW, PH was still associated with greater PPCs (RR 1.66, 95% CI (1.05-2.71), p = 0.036) and increased LOS (median 8.0 days vs. 4.9 days) but not 30-day mortality. Sub-cohort analysis showed no difference in PPCs between pre- and post-capillary PH patients. Conclusions: After covariate balancing, PH was associated with a higher risk for PPCs and prolonged LOS. This elevated PPC risk should be considered during preoperative risk assessment.

'Fear, uncertain, tired…...' psychological distress among pulmonary hypertension patients: a qualitative interview study

BACKGROUND

Patient-centered health care for patients with pulmonary hypertension (PH) is important and requires an understanding of patient experiences. However, there is a lack of approaches to examine what's the effects and how the disease impact patients' psychological well-beings.

METHODS

We conducted qualitative interviews with PH patient representatives to understand patient psychological experiences and inform patient-centered research and care. Participants were chosen from a tertiary hospital located in northwest China. 20 patients with PH who be treated at the hospital (13 participants were women, aged 18-74 years) were strategically selected and individually interviewed. We used qualitative analysis to identify themes relating to existential psychological distress that would clarify the nature of such concerns.

RESULTS

We found that patients experience tremendous psychological distress throughout the treatment process. Four categories that describe patients' psychological experiences emerged: burden of PH treatment, fear and uncertainty about the disease, frustration in social and family role, and lack of recognition of the condition.

CONCLUSIONS

Existential concerns are salient in PH and involve the experience of loss and disruptions to the sense of self and relationships. Healthcare practitioners must work more in collaboration to detect patients' need for support and to develop the patient's own skills to manage daily life. The PH teams should tailor interventions to provide emotional, informational and instrumental support and guidance to patients.

Electrocardiogram Parameters Associated With the Diagnosis of Pulmonary Hypertension in High-Altitude Tibetan Populations: A Retrospective Single-Centre Study

BACKGROUND

Electrocardiogram (ECG) is a commonly used diagnostic method for pulmonary hypertension (PH) in Tibetan areas, but its sensitivity and specificity are not good enough. This study aimed to investigate the ECG parameters associated with the diagnosis of PH in Tibetan areas.

METHODS

Ninety-four PH patients of Tibetan ethnicity who were treated at the hospital between March 2019 and October 2020, and 52 Tibetan individuals as controls, were included. The ECG parameters were compared between groups. Multivariate logistic analysis was performed to identify the ECG parameters that can be used for the diagnosis of PH. The univariate significances of ECG parameters were included in the multivariate analyses, whereas those exhibiting opposite trends between different PH subtypes were excluded.

RESULTS

Two ECG parameters were significant in multivariate analysis. The final model included S wave amplitude in lead V3 (OR 5.81; 95% CI 2.79-12.11; p<0.001) and a negative T wave in leads V1-V3 (OR 0.05; 95% CI 0.01-0.41; p=0.005). The ROC curve analysis on the final model yielded an AUC of 0.830 (95% CI 0.766-0.894; p<0.001), indicating good diagnostic performance. A nomogram for diagnosis of PH was also established using S wave amplitude in lead V3 and a negative T wave in leads V1-V3.

CONCLUSION

The ECG parameters S wave amplitude in lead V3 and a negative T wave in leads V1-V3 were independent factors associated with the diagnosis of PH in high-altitude Tibetan populations.

The role and mechanism of AMPK in pulmonary hypertension

Pulmonary hypertension (PH) is a chronic progressive disease with high mortality. There has been more and more research focusing on the role of AMPK in PH. AMPK consists of three subunits-α, β, and γ. The crosstalk among these subunits ultimately leads to a delicate balance to affect PH, which results in conflicting conclusions about the role of AMPK in PH. It is still unclear how these subunits interfere with each other and achieve balance to improve or deteriorate PH. Several signaling pathways are related to AMPK in the treatment of PH, including AMPK/eNOS/NO pathway, Nox4/mTORC2/AMPK pathway, AMPK/BMP/Smad pathway, and SIRT3-AMPK pathway. Among these pathways, the role and mechanism of AMPK/eNOS/NO and Nox4/mTORC2/AMPK pathways are clearer than others, while the SIRT3-AMPK pathway remains still unclear in the treatment of PH. There are drugs targeting AMPK to improve PH, such as metformin (MET), MET combination, and rhodiola extract. In addition, several novel factors target AMPK for improving PH, such as ADAMTS8, TUFM, and Salt-inducible kinases. However, more researches are needed to explore the specific AMPK signaling pathways involved in these novel factors in the future. In conclusion, AMPK plays an important role in PH.

Correlation between pulmonary vascular performance and hemodynamics in patients with pulmonary arterial hypertension

OBJECTIVE

To explore the correlation between pulmonary vascular performance and hemodynamics in patients with pulmonary arterial hypertension (PAH), using right heart catheterization (RHC) and intravascular ultrasound (IVUS).

METHOD

A total of 60 patients underwent RHC and IVUS examinations. Of these, 27 patients were diagnosed with PAH associated with connective tissue diseases (PAH-CTD group), 18 patients were diagnosed with other types of PAH (other-types-PAH group), and 15 patients were without PAH (control group). The hemodynamics and morphological parameters of pulmonary vessels in PAH patients were assessed using RHC and IVUS.

RESULTS

There were statistically significant differences in right atrial pressure (RAP), pulmonary artery systolic pressure (sPAP), pulmonary artery diastolic pressure (dPAP), mean pulmonary artery pressure (mPAP) and pulmonary vascular resistance (PVR) values between the PAH-CTD group, other-types-PAH group, and the control group (P < .05). No statistically significant difference was noticed in pulmonary artery wedge pressure (PAWP) and cardiac output (CO) values between these three groups (P > .05). The mean wall thickness (MWT), wall thickness percentage (WTP), pulmonary vascular compliance, dilation, elasticity modulus, stiffness index β, and other indicators were significantly different between these three groups (P < .05). Pairwise comparison showed that the average levels of pulmonary vascular compliance and dilation in PAH-CTD group and other-types-PAH group were lower than those in control group, while the average levels of elastic modulus and stiffness index β were higher than those in control group.

CONCLUSION

Pulmonary vascular performance deteriorates in PAH patients, and the performance is better in PAH-CTD patients than in other types of PAH.

Super-massive transfusion during liver transplantation

BACKGROUND

Massive hemorrhage and transfusion during liver transplantation (LT) present great challenges. We aimed to investigate the incidence and risk factors for super-massive transfusion (SMT) and survival outcome and factors that negatively affect survival in patients who received SMT during LT.

STUDY DESIGN AND METHODS

We included adult patients undergoing LT from 2004 to 2019. SMT was defined as transfusion of ≥50 units of red blood cells (RBC) during LT. Independent risk factors were identified by multivariable logistic regression. Ninety-day survival was recorded and factors that negatively affected survival were analyzed by the Cox survival test.

RESULTS

Of 2772 patients, 158 (5.6%) received SMT during LT. Mean RBC transfusion was 72.6 (±23.4) units with a maximum of 168 units. Four variables (MELD-Na score, previous upper abdominal surgery, portal vein thrombosis, and remote retransplant) were independent risk factors for SMT (odds ratio 1.800-8.274, 95% CI 1.008-16.685, all p < .005). The 90-day survival rate in SMT patients was 81.6%. Preoperative pulmonary hypertension and massive postreperfusion transfusion negatively affected 90-day survival (hazard ratio 2.658-4.633, 95% CI 1.144-10.130, and all p < .05).

CONCLUSIONS

In this large retrospective study, we found that SMT occurred in a small percentage of patients and was associated with relatively satisfactory short-term survival. Identification of preoperative risk factors for SMT and factors that negatively affect survival improve our understanding of this unique LT patient population.

MicroRNA and lncRNA as the Future of Pulmonary Arterial Hypertension Treatment

Pulmonary hypertension (PH) is characterized by a progressive increase in pulmonary arterial pressure and pulmonary vascular resistance. In a short time, it leads to right ventricular failure and, consequently, to death. The most common causes of PH include left heart disease and lung disease. Despite the significant development of medicine and related sciences observed in recent years, we still suffer from a lack of effective treatment that would significantly influence the prognosis and prolong life expectancy of patients with PH. One type of PH is pulmonary arterial hypertension (PAH). The pathophysiology of PAH is based on increased cell proliferation and resistance to apoptosis in the small pulmonary arteries, leading to pulmonary vascular remodeling. However, studies conducted in recent years have shown that epigenetic changes may also lie behind the pathogenesis of PAH. Epigenetics is the study of changes in gene expression that are not related to changes in the sequence of nucleotides in DNA. In addition to DNA methylation or histone modification, epigenetic research focuses on non-coding RNAs, which include microRNAs (miRNAs) and long non-coding RNAs (lncRNAs). Preliminary research results give hope that targeting epigenetic regulators may lead to new, potential therapeutic possibilities in the treatment of PAH.

Parameter inference in a computational model of haemodynamics in pulmonary hypertension

Pulmonary hypertension (PH), defined by a mean pulmonary arterial pressure (mPAP) greater than 20 mmHg, is characterized by increased pulmonary vascular resistance and decreased pulmonary arterial compliance. There are few measurable biomarkers of PH progression, but a conclusive diagnosis of the disease requires invasive right heart catheterization (RHC). Patient-specific cardiovascular systems-level computational models provide a potential non-invasive tool for determining additional indicators of disease severity. Using computational modelling, this study quantifies physiological parameters indicative of disease severity in nine PH patients. The model includes all four heart chambers, the pulmonary and systemic circulations. We consider two sets of calibration data: static (systolic and diastolic values) RHC data and a combination of static and continuous, time-series waveform data. We determine a subset of identifiable parameters for model calibration using sensitivity analyses and multi-start inference and perform posterior uncertainty quantification. Results show that additional waveform data enables accurate calibration of the right atrial reservoir and pump function across the PH cohort. Model outcomes, including stroke work and pulmonary resistance-compliance relations, reflect typical right heart dynamics in PH phenotypes. Lastly, we show that estimated parameters agree with previous, non-modelling studies, supporting this type of analysis in translational PH research.

Pathological Roles for Endothelial Colony-Forming Cells in Neonatal and Adult Lung Disease

Endothelial colony-forming cells (ECFCs) are vascular resident and circulating endothelial cell subtypes with potent angiogenic capacity, a hierarchy of single-cell clonogenic potentials, and the ability to participate in de novo blood vessel formation and endothelial repair. Existing literature regarding ECFCs in neonatal and adult pulmonary diseases is confounded by the study of ambiguously defined "endothelial progenitor cells," which are often not true ECFCs. This review contrasts adult and fetal ECFCs, discusses the effect of prematurity on ECFCs, and examines their different pathological roles in neonatal and adult pulmonary diseases, such as bronchopulmonary dysplasia, congenital diaphragmatic hernia, pulmonary artery hypertension, pulmonary fibrosis, and chronic obstructive pulmonary disease. Therapeutic potential is also discussed in light of available preclinical data.

Translational potential of targeting Anoctamin-1-Encoded Calcium-Activated chloride channels in hypertension

Calcium-activated chloride channels (CaCC) provide a depolarizing stimulus to a variety of tissues through chloride efflux in response to a rise in internal Ca²⁺ and voltage. One of these channels, Anoctamin-1 (ANO1 or TMEM16A) is now recognized to play a central role in promoting smooth muscle tone in various types of blood vessels. Its role in hypertension, and thus the therapeutic promise of targeting ANO1, is less straightforward. This review gives an overview of our current knowledge about the potential role ANO1 may play in hypertension within the systemic, portal, and pulmonary vascular systems and the importance of this information when pursuing potential treatment strategies. While the role of ANO1 is well-established in several forms of pulmonary hypertension, its contributions to both the generation of vascular tone and its role in hypertension within the systemic and portal systems are much less clear. This, combined with ANO1's various roles throughout a multitude of tissues throughout the body, command caution when targeting ANO1 as a therapeutic target and may require tissue-selective strategies.

Monocrotaline-Induced Pulmonary Arterial Hypertension and Bosentan Treatment in Rats: Focus on Plasma and Erythrocyte Parameters

The objective of our study was to contribute to the characterization of monocrotaline-induced pulmonary arterial hypertension (PAH) in a rat model, with emphasis on the renin-angiotensin-aldosterone system, parameters of oxidative stress, the activity of matrix metalloproteinases, and erythrocyte parameters. Moreover, we aimed to analyze the effects of bosentan. Experiments were performed on 12-week-old male Wistar rats randomly assigned to 3 groups: control, monocrotaline-treated (60 mg/kg), and monocrotaline combined with bosentan (300 mg/kg/day). Our study confirmed the well-known effects of monocrotaline administration on lungs and the right ventricle, as well as pulmonary arterial pressure. In addition, we observed activation of the alternative pathway of the renin-angiotensin system, namely an increase in angiotensin (Ang) 1-7 and Ang 1-5 together with an increase in Ang I, but without any change in Ang II level, and downregulation of aldosterone 4 weeks after monocrotaline administration. For the first time, modifications of erythrocyte Na,K-ATPase enzyme kinetics were demonstrated as well. Our observations do not support data obtained in PAH patients showing an increase in Ang II levels, increase in oxidative stress, and deterioration in RBC deformability. Although bosentan primarily targets the vascular smooth muscle, our study confirmed its antioxidant effect. The obtained data suggest that besides the known action of bosentan, it decreases heart rate and increases erythrocyte deformability, and hence could have a beneficial hemodynamic effect in the PAH condition.

Relationships between sexual function, mental health, and quality of life of female patients with pulmonary arterial hypertension associated with congenital heart disease

In recent years, the treatment of pulmonary arterial hypertension (PAH) has gradually increased, including new drugs and surgical methods, the mortality rate of PAH patients has significantly decreased, and the average survival rate has significantly improved. However, there was no obvious improvement in sexual health, mental health, and quality of life (QoL) in patients with PAH. Although an important dimension of QoL, little is known about sexual health and sexual health-related QoL of patients with PAH in China. In this study, the female sexual function index (FSFI) scale, the Symptom Checklist-90 (SCL-90), and emPHasis-10 were used to evaluate PAH associated with congenital heart disease (CHD-PAH) patients' sexual function, mental health, and QoL. The score of sexual function in female CHD-PAH patients ranged from 4.40 to 34.80 points, and the average score was 26.80 (19.00-27.80) points. The detection rate of sexual dysfunction was 48.30%. The FSFI score of all dimensions of the sexual dysfunction group was significantly lower than that of the nonsexual dysfunction group. In addition, the scores of SCL-90 and emPHasis-10 were significantly higher than that of the nonsexual dysfunction group (p < 0.01). The sexual function was negatively correlated with mental health (r = -0.58, p < 0.01) and QoL (r = -0.62, p < 0.01) in female CHD-PAH patients. The sexual function of female patients with CHD-PAH is not optimistic. Sexual health may impact mental health and overall QoL in female PAH patients. Reasonable intervention measures should be taken to improve their sexual health, so as to improve their overall QoL.

The emerging role of NOTCH3 receptor signalling in human lung diseases

The mammalian respiratory system or lung is a tree-like branching structure, and the main site of gas exchange with the external environment. Structurally, the lung is broadly classified into the proximal (or conducting) airways and the distal alveolar region, where the gas exchange occurs. In parallel with the respiratory tree, the pulmonary vasculature starts with large pulmonary arteries that subdivide rapidly ending in capillaries adjacent to alveolar structures to enable gas exchange. The NOTCH signalling pathway plays an important role in lung development, differentiation and regeneration post-injury. Signalling via the NOTCH pathway is mediated through activation of four NOTCH receptors (NOTCH1-4), with each receptor capable of regulating unique biological processes. Dysregulation of the NOTCH pathway has been associated with development and pathophysiology of multiple adult acute and chronic lung diseases. This includes accumulating evidence that alteration of NOTCH3 signalling plays an important role in the development and pathogenesis of chronic obstructive pulmonary disease, lung cancer, asthma, idiopathic pulmonary fibrosis and pulmonary arterial hypertension. Herein, we provide a comprehensive summary of the role of NOTCH3 signalling in regulating repair/regeneration of the adult lung, its association with development of lung disease and potential therapeutic strategies to target its signalling activity.

Molecular Pathways in Pulmonary Arterial Hypertension

Pulmonary arterial hypertension is a multifactorial, chronic disease process that leads to pulmonary arterial endothelial dysfunction and smooth muscular hypertrophy, resulting in impaired pliability and hemodynamics of the pulmonary vascular system, and consequent right ventricular dysfunction. Existing treatments target limited pathways with only modest improvement in disease morbidity, and little or no improvement in mortality. Ongoing research has focused on the molecular basis of pulmonary arterial hypertension and is going to be important in the discovery of new treatments and genetic pathways involved. This review focuses on the molecular pathogenesis of pulmonary arterial hypertension.

Salt-inducible kinases: new players in pulmonary arterial hypertension?

Salt-inducible kinases (SIKs) are serine/threonine kinases belonging to the AMP-activated protein kinase (AMPK) family. Accumulating evidence indicates that SIKs phosphorylate multiple targets, including histone deacetylases (HDACs) and cAMP response element-binding protein (CREB)-regulated transcriptional coactivators (CRTCs), to coordinate signaling pathways implicated in metabolism, cell growth, proliferation, apoptosis, and inflammation. These pathways downstream of SIKs are altered not only in pathologies like cancer, systemic hypertension, and inflammatory diseases, but also in pulmonary arterial hypertension (PAH), a multifactorial disease characterized by pulmonary vasoconstriction, inflammation and remodeling of pulmonary arteries owing to endothelial dysfunction and aberrant proliferation of smooth muscle cells (SMCs). In this opinion article, we present evidence of SIKs as modulators of key signaling pathways involved in PAH pathophysiology and discuss the potential of SIKs as therapeutic targets for PAH, emphasizing the need for deeper molecular insights on PAH.

A Brief Review on Gender Differences in Mexican-Mestizo Patients with Pulmonary Arterial Hypertension (PAH) at a Tertiary-Level Hospital

INTRODUCTION

Pulmonary hypertension (PH) is a hemodynamic condition with different etiological groups but common pathophysiology. Gender differences have been studied in group 1 of the PH classification, the pulmonary arterial hypertension (PAH) group. PAH has an etiopathogenic basis in sex hormones and directly affects the pulmonary vasculature and the heart. Gender differences are observed before and after the age of 45 when women lose the cardioprotective effect of estrogen.

METHODS

A retrospective cohort study in adult patients ≤ 45 years and > 45 years. We compared hemodynamic, echocardiographic, and imaging variables that demonstrated gender differences in adult patients with PAH below and above 45 years.

RESULTS

Gender differences in adults ≤ 45 years were significant for the pronounced pulmonic component of the second heart sound (P2) and the right atrium pressure (RAP), on the other hand, more significant sex differences were observed in patients over 45 years of age including the pronounced pulmonic component of P2 (greater in women), the BNP had a higher median in men, the same happened in the echocardiographic data referring to the area of the right atrium (ARA) and TAPSE, abnormal values predominate in men.

DISCUSSION

Although PAH has greater incidence and prevalence in women, the lesions corresponding to cardiac remodeling that subsequently led to right ventricular failure are more remarkable in men, raising their mortality. These findings help recognize its clinical usefulness and propose new research studies aimed at mortality and new pharmacological therapies that might unveil the pathophysiological mechanisms to treat PAH.

Mechanisms of pulmonary vascular dysfunction in pulmonary hypertension and implications for novel therapies

Pulmonary hypertension (PH) is a serious disease characterized by various degrees of pulmonary vasoconstriction and progressive fibroproliferative remodeling and inflammation of the pulmonary arterioles that lead to increased pulmonary vascular resistance, right ventricular hypertrophy, and failure. Pulmonary vascular tone is regulated by a balance between vasoconstrictor and vasodilator mediators, and a shift in this balance to vasoconstriction is an important component of PH pathology, Therefore, the mainstay of current pharmacological therapies centers on pulmonary vasodilation methodologies that either enhance vasodilator mechanisms such as the NO-cGMP and prostacyclin-cAMP pathways and/or inhibit vasoconstrictor mechanisms such as the endothelin-1, cytosolic Ca2+, and Rho-kinase pathways. However, in addition to the increased vascular tone, many patients have a "fixed" component in their disease that involves altered biology of various cells in the pulmonary vascular wall, excessive pulmonary artery remodeling, and perivascular fibrosis and inflammation. Pulmonary arterial smooth muscle cell (PASMC) phenotypic switch from a contractile to a synthetic and proliferative phenotype is an important factor in pulmonary artery remodeling. Although current vasodilator therapies also have some antiproliferative effects on PASMCs, they are not universally successful in halting PH progression and increasing survival. Mild acidification and other novel approaches that aim to reverse the resident pulmonary vascular pathology and structural remodeling and restore a contractile PASMC phenotype could ameliorate vascular remodeling and enhance the responsiveness of PH to vasodilator therapies.

Sex-Dependent Protective Effect of Combined Application of Solubilized Ubiquinol and Selenium on Monocrotaline-Induced Pulmonary Hypertension in Wistar Rats

Ubiquinol exhibits anti-inflammatory and antioxidant properties. Selenium is a part of a number of antioxidant enzymes. The monocrotaline inducible model of pulmonary hypertension used in this study includes pathological links that may act as an application for the use of ubiquinol with high bioavailability and selenium metabolic products. On day 1, male and female rats were subcutaneously injected with a water-alcohol solution of monocrotaline or only water-alcohol solution. On days 7 and 14, some animals were intravenously injected with either ubiquinol’s vehicle or solubilized ubiquinol, or orally with selenium powder daily, starting from day 7, or received both ubiquinol + selenium. Magnetic resonance imaging of the lungs was performed on day 20. Hemodynamic parameters and morphometry were measured on day 22. An increased right ventricle systolic pressure in relation to control was demonstrated in all groups of animals of both sexes, except the group of males receiving the combination of ubiquinol + selenium. The relative mass of the right ventricle did not differ from the control in all groups of males and females receiving either ubiquinol alone or the combination. Magnetic resonance imaging revealed impaired perfusion in almost all animals examined, but pulmonary fibrosis developed in only half of the animals in the ubiquinol group. Intravenous administration of ubiquinol has a protective effect on monocrotaline-induced pulmonary hypertension development resulting in reduced right ventricle hypertrophy, and lung mass. Ubiquinol + selenium administration resulted in a less severe increase in the right ventricle systolic pressure in male rats but not in females 3 weeks after the start of the experiment. This sex-dependent effect was not observed in the influence of ubiquinol alone.