scholarly journals Docosahexaenoic acid causes rapid pulmonary arterial relaxation via KCa channel-mediated hyperpolarisation in pulmonary hypertension

2016 ◽  
Vol 48 (4) ◽  
pp. 1127-1136 ◽  
Author(s):  
Chandran Nagaraj ◽  
Bi Tang ◽  
Bence M. Nagy ◽  
Rita Papp ◽  
Pritesh P. Jain ◽  
...  

Cardioprotective benefits of ω-3 fatty acids such as docosahexaenoic acid (DHA) are well established, but the regulatory effect of DHA on vascular tone and pressure in pulmonary hypertension is largely unknown.As DHA is a potent regulator of K+ channels, we hypothesised that DHA modulates the membrane potential of pulmonary artery smooth muscle cells (PASMCs) through K+ channels and thus exerts its effects on pulmonary vascular tone and pressure.We show that DHA caused dose-dependent activation of the calcium-activated K+ (KCa) current in primary human PASMCs and endothelium-dependent relaxation of pulmonary arteries. This vasodilation was significantly diminished in KCa–/– (Kcnma1–/–) mice. In vivo, acute DHA returned the right ventricular systolic pressure in the chronic hypoxia-induced pulmonary hypertension animal model to the level of normoxic animals. Interestingly, in idiopathic pulmonary arterial hypertension the KCa channels and their subunits were upregulated. DHA activated KCa channels in these human PASMCs and hyperpolarised the membrane potential of the idiopathic pulmonary arterial hypertension PASMCs to that of the PASMCs from healthy donors.Our findings indicate that DHA activates PASMC KCa channels leading to vasorelaxation in pulmonary hypertension. This effect might provide a molecular explanation for the previously undescribed role of DHA as an acute vasodilator in pulmonary hypertension.

2020 ◽  
Vol 19 (4) ◽  
pp. 240-243
Author(s):  
Adam Maxwell ◽  
◽  
Thomas Holman ◽  
Timea Novak ◽  
◽  
...  

A 31-year old woman presented to the acute medical unit 9 days post-partum with shortness of breath and peripheral oedema. Initially suspected to have either a pulmonary embolism or post-partum cardiomyopathy, she proceeded to have imaging including a CT Pulmonary angiogram and echocardiogram, which were suggestive of pulmonary hypertension and severe right heart failure. Her history and other investigations did not reveal any obvious cause for this. She was transferred to a specialist centre where she was diagnosed with Idiopathic Pulmonary Arterial Hypertension (IPAH), previously known as primary pulmonary hypertension. Shortness of breath during pregnancy and in the postpartum period is a relatively common acute medical presentation. Whilst IPAH is a rare diagnosis, it carries a high mortality rate, particularly in pregnancy, and requires prompt specialist investigation, diagnosis and management.


2019 ◽  
Vol 9 (4) ◽  
pp. 204589401985753
Author(s):  
Lina Caicedo ◽  
Rachel Hopper ◽  
Humberto Garcia Aguilar ◽  
Dunbar Ivy ◽  
Dora Haag ◽  
...  

The aim of this study was to determine practice patterns and inter-institutional variability in how acute vasoreactivity testing (AVT) is performed and interpreted in pediatrics throughout the world. A survey was offered to physicians affiliated with the Pediatric & Congenital Heart Disease Taskforce of the Pulmonary Vascular Research Institute (PVRI), the Pediatric Pulmonary Hypertension Network (PPHNET), or the Spanish Registry for Pediatric Pulmonary Hypertension (REHIPED), from February to December 2016. The survey requested data about the site-specific protocol for AVT and subsequent management of pediatric patients with idiopathic pulmonary arterial hypertension (IPAH) or heritable PAH (HPAH). Twenty-eight centers from 13 countries answered the survey. AVT is performed in most centers using inhaled nitric oxide (iNO). Sitbon criteria was used in 39% of the centers, Barst criteria in 43%, and other criteria in 18%. First-line therapy for positive AVT responders in functional class (FC) I/II was calcium channel blocker (CCB) in 89%, but only in 68% as monotherapy. Most centers (71%) re-evaluated AVT-positive patients hemodynamics after 6–12 months; 29% of centers re-evaluated based only on clinical criteria. Most centers (64%) considered a good response as remaining in FC I or II, with near normalization of pulmonary arterial pressure and pulmonary vascular resistance, but a stable FC I/II alone was sufficient criteria in 25% of sites. Protocols and diagnostic criteria for AVT, and therapeutic approaches during follow-up, were highly variable across the world. Reported clinical practice is not fully congruent with current guidelines, suggesting the need for additional studies that better define the prognostic value of AVT for pediatric IPAH patients.


2010 ◽  
Vol 298 (4) ◽  
pp. H1235-H1248 ◽  
Author(s):  
Revathi Rajkumar ◽  
Kazuhisa Konishi ◽  
Thomas J. Richards ◽  
David C. Ishizawar ◽  
Andrew C. Wiechert ◽  
...  

Idiopathic pulmonary arterial hypertension (PAH) is a life-threatening condition characterized by pulmonary arteriolar remodeling. This investigation aimed to identify genes involved specifically in the pathogenesis of PAH and not other forms of pulmonary hypertension (PH). Using genomewide microarray analysis, we generated the largest data set to date of RNA expression profiles from lung tissue specimens from 1) 18 PAH subjects and 2) 8 subjects with PH secondary to idiopathic pulmonary fibrosis (IPF) and 3) 13 normal subjects. A molecular signature of 4,734 genes discriminated among these three cohorts. We identified significant novel biological changes that were likely to contribute to the pathogenesis of PAH, including regulation of actin-based motility, protein ubiquitination, and cAMP, transforming growth factor-β, MAPK, estrogen receptor, nitric oxide, and PDGF signaling. Bone morphogenic protein receptor type II expression was downregulated, even in subjects without a mutation in this gene. Women with PAH had higher expression levels of estrogen receptor 1 than normal women. Real-time quantitative PCR confirmed differential expression of the following genes in PAH relative to both normal controls and PH secondary to IPF: a disintegrin-like and metalloprotease with thrombospondin type 1 motif 9, cell adhesion molecule with homology to L1CAM, cytochrome b558and β-polypeptide, coagulation factor II receptor-like 3, A-myb myeloblastosis viral oncogene homolog 1, nuclear receptor coactivator 2, purinergic receptor P2Y, platelet factor 4, phospholamban, and tropomodulin 3. This study shows that PAH and PH secondary to IPF are characterized by distinct gene expression signatures, implying distinct pathophysiological mechanisms.


2019 ◽  
Vol 32 (11) ◽  
pp. 1109-1117
Author(s):  
Jun-Han Zhao ◽  
Yang-Yang He ◽  
Shan-Shan Guo ◽  
Yi Yan ◽  
Zhe Wang ◽  
...  

Abstract BACKGROUND Pulmonary arterial hypertension (PAH) is a severe progressive disease with systemic metabolic dysregulation. Monocrotaline (MCT)-induced and hypoxia-induced pulmonary hypertension (PH) rodent models are the most widely used preclinical models, however, whether or not these preclinical models recapitulate metabolomic profiles of PAH patients remain unclear. METHODS In this study, a targeted metabolomics panel of 126 small molecule metabolites was conducted. We applied it to the plasma of the 2 preclinical rodent models of PH and 30 idiopathic pulmonary arterial hypertension (IPAH) patients as well as 30 healthy controls to comparatively assess the metabolomic profiles of PAH patients and rodent models. RESULTS Significantly different metabolomics profiling and pathways were shown among the 2 classical rodent models and IPAH patients. Pathway analysis demonstrated that methionine metabolism and urea cycle metabolism were the most significant pathway involved in the pathogenesis of hypoxia-induced PH model and MCT-induced model, respectively, and both of them were also observed in the dysregulated pathways in IPAH patients. CONCLUSIONS These 2 models may develop PAH through different metabolomic pathways and each of the 2 classical PH model resembles IPAH patients in certain aspects.


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