scholarly journals The mechanism of ions in pulmonary hypertension

2021 ◽  
Vol 11 (1) ◽  
pp. 204589402098794
Author(s):  
Guogu Liu ◽  
Daiyan Fu ◽  
Heshen Tian ◽  
Aiguo Dai
Keyword(s):  
Pulmonary Hypertension ◽  
Calcium Ion ◽  
Pulmonary Arteries ◽  
Chloride Ion ◽  
Vasoactive Substances ◽  
Pulmonary Vasoconstriction ◽  
Concentration Of Ions ◽  
Inducing Factors ◽  
Effective Drugs ◽  
Pathological Manifestation

Pulmonary hypertension（PH）is a kind of hemodynamic and pathophysiological state, in which the pulmonary artery pressure (PAP) rises above a certain threshold. The main pathological manifestation is pulmonary vasoconstriction and remodelling progressively. More and more studies have found that ions play a major role in the pathogenesis of PH. Many vasoactive substances, inflammatory mediators, transcription-inducing factors, apoptosis mediators, redox substances and translation modifiers can control the concentration of ions inside and outside the cell by regulating the activity of ion channels, which can regulate vascular contraction, cell proliferation, migration, apoptosis, inflammation and other functions. We all know that there are no effective drugs to treat PH. Ions are involved in the occurrence and development of PH, so it is necessary to clarify the mechanism of ions in PH as a therapeutic target for PH. The main ions involved in PH are calcium ion (Ca2+), potassium ion (K+), sodium ion (Na+) and chloride ion (Cl–). Here, we mainly discuss the distribution of these ions and their channels in pulmonary arteries and their role in the pathogenesis of PH.

scholarly journals AMPK and Pulmonary Hypertension: Crossroads Between Vasoconstriction and Vascular Remodeling

2021 ◽  
Vol 9 ◽  
Author(s):  
Qiang Zhao ◽  
Ping Song ◽  
Ming-Hui Zou
Keyword(s):  
Pulmonary Hypertension ◽  
Vascular Remodeling ◽  
Early Stage ◽  
Pulmonary Arteries ◽  
Adenosine Monophosphate ◽  
Serine Threonine Kinase ◽  
Threonine Kinase ◽  
Pulmonary Vasoconstriction ◽  
Life Threatening

Pulmonary hypertension (PH) is a debilitating and life-threatening disease characterized by increased blood pressure within the pulmonary arteries. Adenosine monophosphate-activated protein kinase (AMPK) is a heterotrimeric serine-threonine kinase that contributes to the regulation of metabolic and redox signaling pathways. It has key roles in the regulation of cell survival and proliferation. The role of AMPK in PH is controversial because both inhibition and activation of AMPK are preventive against PH development. Some clinical studies found that metformin, the first-line antidiabetic drug and the canonical AMPK activator, has therapeutic efficacy during treatment of early-stage PH. Other study findings suggest the use of metformin is preferentially beneficial for treatment of PH associated with heart failure with preserved ejection fraction (PH-HFpEF). In this review, we discuss the “AMPK paradox” and highlight the differential effects of AMPK on pulmonary vasoconstriction and pulmonary vascular remodeling. We also review the effects of AMPK activators and inhibitors on rescue of preexisting PH in animals and include a discussion of gender differences in the response to metformin in PH.

Collateral ventilation may protect against high-altitude pulmonary hypertension

1981 ◽  
Vol 51 (5) ◽  
pp. 1251-1256 ◽  
Author(s):  
T. Kuriyama ◽  
W. W. Wagner
Keyword(s):  
Pulmonary Hypertension ◽  
High Altitude ◽  
Pulmonary Arteries ◽  
Time Constants ◽  
Arterial Walls ◽  
Ventilation Time ◽  
Pulmonary Vasoconstriction ◽  
Local Ventilation ◽  
Arterial Constriction ◽  
Collateral Ventilation

We propose that the pulmonary hypertension developed by cattle and swine at high altitude is associated with their lack of collateral ventilation. We reason that if collateral ventilation helps keep interregional oxygen tensions homogeneous, then in its absence, local ventilation-perfusion balance must rely on arterial constriction; the additional work causes arterial walls to be more muscular at low altitude, a characteristic of cattle and swine that appears prerequisite for the development of pulmonary hypertension at high altitude. In contrast, species with collateral ventilation, e.g., dogs, have thin-walled pulmonary arteries and therefore can not sustain pulmonary vasoconstriction at altitude. Sheep, however, challenge the hypothesis, because their thick lobular septae should block collateral ventilation, yet they have thin pulmonary arteries and resist high-altitude hypertension. We measured collateral ventilation by determining how long it takes air injected into isolated segments to escape. Cattle and swine had no collateral ventilation (time constants greater than 30 s), whereas dogs and sheep had collateral ventilation (time constants less than 0.8 s). These data support the hypothesis that only species without collateral ventilation develop pulmonary hypertension at high altitude.

scholarly journals TRPV4 channel contributes to serotonin-induced pulmonary vasoconstriction and the enhanced vascular reactivity in chronic hypoxic pulmonary hypertension

2013 ◽  
Vol 305 (7) ◽  
pp. C704-C715 ◽  
Author(s):  
Yang Xia ◽  
Zhenzhen Fu ◽  
Jinxing Hu ◽  
Chun Huang ◽  
Omkar Paudel ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Vascular Reactivity ◽  
Transient Receptor Potential ◽  
Pulmonary Arteries ◽  
Receptor Potential ◽  
Induced Response ◽  
Transient Receptor Potential Vanilloid ◽  
Hypoxic Pulmonary Hypertension ◽  
Mechanical Coupling ◽  
Pulmonary Vasoconstriction

Transient receptor potential vanilloid 4 (TRPV4) is a mechanosensitive channel in pulmonary arterial smooth muscle cells (PASMCs). Its upregulation by chronic hypoxia is associated with enhanced myogenic tone, and genetic deletion of trpv4 suppresses the development of chronic hypoxic pulmonary hypertension (CHPH). Here we further examine the roles of TRPV4 in agonist-induced pulmonary vasoconstriction and in the enhanced vasoreactivity in CHPH. Initial evaluation of TRPV4-selective antagonists HC-067047 and RN-1734 in KCl-contracted pulmonary arteries (PAs) of trpv4−/−mice found that submicromolar HC-067047 was devoid of off-target effect on pulmonary vasoconstriction. Inhibition of TRPV4 with 0.5 μM HC-067047 significantly reduced the sensitivity of serotonin (5-HT)-induced contraction in wild-type (WT) PAs but had no effect on endothelin-1 or phenylephrine-activated response. Similar shift in the concentration-response curve of 5-HT was observed in trpv4−/−PAs, confirming specific TRPV4 contribution to 5-HT-induced vasoconstriction. 5-HT-induced Ca2+response was attenuated by HC-067047 in WT PASMCs but not in trpv4−/−PASMCs, suggesting TRPV4 is a major Ca2+pathway for 5-HT-induced Ca2+mobilization. Nifedipine also attenuated 5-HT-induced Ca2+response in WT PASMCs but did not cause further reduction in the presence of HC-067047, suggesting interdependence of TRPV4 and voltage-gated Ca2+channels in the 5-HT response. Chronic exposure (3–4 wk) of WT mice to 10% O2caused significant increase in 5-HT-induced maximal contraction, which was partially reversed by HC-067047. In concordance, the enhancement of 5-HT-induced contraction was significantly reduced in PAs of CH trpv4−/−mice and HC-067047 had no further effect on the 5-HT induced response. These results suggest unequivocally that TRPV4 contributes to 5-HT-dependent pharmaco-mechanical coupling and plays a major role in the enhanced pulmonary vasoreactivity to 5-HT in CHPH.

Reduced vasodilator response to ANF in hypoxia-induced pulmonary hypertension in the newborn piglet

1997 ◽  
Vol 273 (2) ◽  
pp. L289-L295 ◽  
Author(s):  
T. Perreault ◽  
J. Baribeau ◽  
R. Gosselin ◽  
J. Gutkowska
Keyword(s):  
Pulmonary Hypertension ◽  
Natriuretic Peptide ◽  
Vascular Reactivity ◽  
Pulmonary Arteries ◽  
Pulmonary Vasculature ◽  
Binding Characteristics ◽  
Pulmonary Vasoconstriction ◽  
Clearance Receptor ◽  
Circulating Levels ◽  
Specific Ligand

Recent evidence suggests that, in adult animals with hypoxia-induced pulmonary hypertension, atrial natriuretic factor (ANF) may modulate pulmonary vascular tone and may have a protective effect. However, its role in the pathogenesis of pulmonary hypertension of the newborn is unknown. We hypothesized that, in the newborn, hypoxia-induced pulmonary hypertension would result in ANF receptor downregulation, resulting in decreased dilator response, favoring pulmonary vasoconstriction and vascular remodeling. Therefore, we studied, in 1-day-old piglets exposed to hypoxia (fraction of inspired O2 0.10) for 3 or 14 days to induce pulmonary hypertension, 1) ANF release by measuring circulating levels of ANF by radioimmunoassay in pulmonary artery and veins, 2) pulmonary vascular reactivity to ANF using isolated perfused lungs, and 3) binding characteristics by examining the concentration dependence of ANF binding and competitive binding of 125I-labeled ANF with ANF, brain natriuretic peptide, C-type natriuretic peptide, and the specific ligand for ANF clearance receptor on microsomes from pulmonary arteries (down to 100 microns). ANF circulating levels are increased after exposure to hypoxia compared with normoxia, reaching significance at 14 days (P < 0.005). The magnitude of ANF dilator response is diminished after exposure to hypoxia (P < 0.05). Saturation studies reveal that the number of ANF receptors is diminished in hypoxia after 3 days but reaches significance after 14 days (P < 0.01) compared with their respective normoxic control. At either condition, the majority of these receptors are of the functional type, whereas clearance receptors are virtually undectable. These results suggest that hypoxia increases circulating ANF and causes a decreased responsiveness of the pulmonary vasculature to ANF. Receptor down-regulation may explain part of the reduced dilator response, although the involvement of other mechanisms is not excluded.

scholarly journals Cytochrome P450 Epoxygenase-Dependent Activation of TRPV4 Channel Participates in Enhanced Serotonin-Induced Pulmonary Vasoconstriction in Chronic Hypoxic Pulmonary Hypertension

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Yang Xia ◽  
Lexin Xia ◽  
Zhou Jin ◽  
Rui Jin ◽  
Omkar Paudel ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Cytochrome P450 ◽  
Transient Receptor Potential ◽  
Chronic Hypoxia ◽  
Pulmonary Arteries ◽  
Specific Inhibitor ◽  
Receptor Potential ◽  
Inhibitory Effect ◽  
Transient Receptor Potential Vanilloid ◽  
Pulmonary Vasoconstriction

Transient receptor potential vanilloid 4 (TRPV4) is a multi-functional non-selective channel expressed in pulmonary vasculatures. TRPV4 contributes to serotonin- (5-HT-) induced pulmonary vasoconstriction and is responsible in part for the enhanced 5-HT response in pulmonary arteries (PAs) of chronic hypoxia mice. Epoxyeicosatrienoic acid (EET) is an endogenous agonist of TRPV4 and is known to regulate vasoreactivity. The levels of EETs, the expression of cytochrome P450 (CYP) epoxygenase for EET production, and epoxide hydrolase for EET degradation are altered by chronic hypoxia. Here, we examined the role of EET-dependent TRPV4 activation in the 5-HT-mediated PA contraction. In PAs of normoxic mice, inhibition of TRPV4 with a specific inhibitor HC-067047 caused a decrease in the sensitivity of 5-HT-induced PA contraction without affecting the maximal contractile response. Application of the cytochrome P450 epoxygenase inhibitor MS-PPOH had no effect on the vasoreactivity to 5-HT. In contrast, inhibition of CYP epoxygenase or TRPV4 both attenuated the 5-HT-elicited maximal contraction to a comparable level in PAs of chronic hypoxic mice. Moreover, the inhibitory effect of MS-PPOH on the 5-HT-induced contraction was obliterated in PAs of chronic hypoxic trpv4-/- mice. These results suggest that TRPV4 contributes to the enhanced 5-HT-induced vasoconstriction in chronic hypoxic PAs, in part via the CYP-EET-TRPV4 pathway. Our results further support the notion that manipulation of TRPV4 function may offer a novel therapeutic strategy for the treatment of hypoxia-related pulmonary hypertension.

Hypoxic Pulmonary Vasoconstriction and Chronic Lung Disease

2013 ◽  
Vol 12 (3) ◽  
pp. 135-144 ◽  
Author(s):  
Erik R. Swenson
Keyword(s):  
Pulmonary Hypertension ◽  
Lung Disease ◽  
Hypoxic Pulmonary Vasoconstriction ◽  
World Health ◽  
Disease States ◽  
Pulmonary Vasoconstriction ◽  
Local Ventilation ◽  
Pulmonary Vascular Endothelium ◽  
Health And Disease ◽  
Health Organization

Hypoxic vasoconstriction in the lung is a unique and fundamental characteristic of the pulmonary circulation. It functions in health and disease states to better preserve ventilation-perfusion matching by diverting blood flow to better ventilated regions when local ventilation is compromised. As more areas of lung become hypoxic either with high altitude or global lung disease, then hypoxic pulmonary vasoconstriction (HPV) becomes less effective in ventilation-perfusion matching and can lead to pulmonary hypertension. HPV is intrinsic to the vascular smooth muscle and its mechanisms remain poorly understood. In addition, the pulmonary vascular endothelium, red cells, lung innervation, and numerous circulating vasoactive agents also affect the strength of HPV. This review will discuss the pathophysiology of HPV and address its role in pulmonary hypertension associated with World Health Organization Group 3 diseases. When sustained beyond many hours, HPV may initiate pulmonary vascular remodeling and lead to more fixed and less oxygen-responsive pulmonary hypertension if the hypoxic stimulus is maintained.

Pulmonary Endarterectomy: Assessment of Operability, Surgical Description, and Post-op Care

2014 ◽  
Vol 12 (4) ◽  
pp. 186-192 ◽  
Author(s):  
David Poch ◽  
Victor Pretorius
Keyword(s):  
Pulmonary Hypertension ◽  
Pulmonary Artery ◽  
Pulmonary Artery Pressure ◽  
Pulmonary Arteries ◽  
Chronic Thromboembolic Pulmonary Hypertension ◽  
Pulmonary Artery Wedge Pressure ◽  
Pulmonary Endarterectomy ◽  
Pulmonary Thromboendarterectomy ◽  
Thromboembolic Pulmonary Hypertension ◽  
Wedge Pressure

Chronic thromboembolic pulmonary hypertension (CTEPH) is defined as a mean pulmonary artery pressure ≥25 mm Hg and pulmonary artery wedge pressure ≤15 mm Hg in the presence of occlusive thrombi within the pulmonary arteries. Surgical pulmonary thromboendarterectomy (PTE) is considered the best treatment option for CTEPH.

scholarly journals Oxygen-Sensitivity and Pulmonary Selectivity of Vasodilators as Potential Drugs for Pulmonary Hypertension

Antioxidants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 155
Author(s):  
Daniel Morales-Cano ◽  
Bianca Barreira ◽  
Beatriz De Olaiz Navarro ◽  
María Callejo ◽  
Gema Mondejar-Parreño ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Gas Exchange ◽  
Pulmonary Circulation ◽  
Pulmonary Arteries ◽  
Blood Perfusion ◽  
Mesenteric Arteries ◽  
Oxygen Sensitivity ◽  
Low Oxygen ◽  
Oxygen Selectivity

Current approved therapies for pulmonary hypertension (PH) aim to restore the balance between endothelial mediators in the pulmonary circulation. These drugs may exert vasodilator effects on poorly oxygenated vessels. This may lead to the derivation of blood perfusion towards low ventilated alveoli, i.e., producing ventilation-perfusion mismatch, with detrimental effects on gas exchange. The aim of this study is to analyze the oxygen-sensitivity in vitro of 25 drugs currently used or potentially useful for PH. Additionally, the study analyses the effectiveness of these vasodilators in the pulmonary vs. the systemic vessels. Vasodilator responses were recorded in pulmonary arteries (PA) and mesenteric arteries (MA) from rats and in human PA in a wire myograph under different oxygen concentrations. None of the studied drugs showed oxygen selectivity, being equally or more effective as vasodilators under conditions of low oxygen as compared to high oxygen levels. The drugs studied showed low pulmonary selectivity, being equally or more effective as vasodilators in systemic than in PA. A similar behavior was observed for the members within each drug family. In conclusion, none of the drugs showed optimal vasodilator profile, which may limit their therapeutic efficacy in PH.

scholarly journals The Role of JAK/STAT Molecular Pathway in Vascular Remodeling Associated with Pulmonary Hypertension

2021 ◽  
Vol 22 (9) ◽  
pp. 4980
Author(s):  
Inés Roger ◽  
Javier Milara ◽  
Paula Montero ◽  
Julio Cortijo
Keyword(s):  
Pulmonary Hypertension ◽  
Smooth Muscle ◽  
Pulmonary Artery ◽  
Vascular Remodeling ◽  
Pulmonary Arteries ◽  
Clinical Manifestations ◽  
Different Types ◽  
Artery Remodeling ◽  
Stat Pathway ◽  
Pulmonary Artery Remodeling

Pulmonary hypertension is defined as a group of diseases characterized by a progressive increase in pulmonary vascular resistance (PVR), which leads to right ventricular failure and premature death. There are multiple clinical manifestations that can be grouped into five different types. Pulmonary artery remodeling is a common feature in pulmonary hypertension (PH) characterized by endothelial dysfunction and smooth muscle pulmonary artery cell proliferation. The current treatments for PH are limited to vasodilatory agents that do not stop the progression of the disease. Therefore, there is a need for new agents that inhibit pulmonary artery remodeling targeting the main genetic, molecular, and cellular processes involved in PH. Chronic inflammation contributes to pulmonary artery remodeling and PH, among other vascular disorders, and many inflammatory mediators signal through the JAK/STAT pathway. Recent evidence indicates that the JAK/STAT pathway is overactivated in the pulmonary arteries of patients with PH of different types. In addition, different profibrotic cytokines such as IL-6, IL-13, and IL-11 and growth factors such as PDGF, VEGF, and TGFβ1 are activators of the JAK/STAT pathway and inducers of pulmonary remodeling, thus participating in the development of PH. The understanding of the participation and modulation of the JAK/STAT pathway in PH could be an attractive strategy for developing future treatments. There have been no studies to date focused on the JAK/STAT pathway and PH. In this review, we focus on the analysis of the expression and distribution of different JAK/STAT isoforms in the pulmonary arteries of patients with different types of PH. Furthermore, molecular canonical and noncanonical JAK/STAT pathway transactivation will be discussed in the context of vascular remodeling and PH. The consequences of JAK/STAT activation for endothelial cells and pulmonary artery smooth muscle cells’ proliferation, migration, senescence, and transformation into mesenchymal/myofibroblast cells will be described and discussed, together with different promising drugs targeting the JAK/STAT pathway in vitro and in vivo.

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