Bosentan, a dual endothelin receptor blocker, has been used clinically to treat idiopathic pulmonary arterial hypertension (IPAH). However, the mechanism of its antiproliferative effect on pulmonary artery smooth muscle cells (PASMCs) remains unclear. A rise in cytoplasmic Ca2+ stimulates PASMC proliferation and the canonical transient receptor potential (TRPC) channels are an important pathway...

TO THE EDITOR: We read with interest the article by Ormiston et al. (2) “The enzymatic degradation of hyaluronan is associated with disease progression in experimental pulmonary hypertension” and wish to make a few comments. In Ormiston and colleagues’ interpretation of our study, they accurately described the increased levels of hyaluronan (HA) we reported in pulmonary artery smooth muscle cel...

RATIONALE Angiopoietins are involved in blood vessel maturation and remodeling. OBJECTIVES One consequence of endothelium-specific tyrosine kinase-2 (Tie2) receptor activation by angiopoietin-1 (Ang1) is the release of endothelium-derived growth factors that recruit vascular wall cells. We investigated this process in idiopathic pulmonary arterial hypertension (iPAH). METHODS Ang1, Ang2, an...

Rationale: Angiopoietins are involved in blood-vessel maturation and remodeling. Objectives: One consequence of endothelial-specific receptor Tie2 activation by angiopoietin-1 (Ang1) is the release of endothelial-derived growth factors that recruit vascular wall cells. We investigated this process in idiopathic pulmonary arterial hypertension (iPAH). Methods: Ang1, Ang2, total and phosphorylate...

Objectives: To characterize the demographic and clinical profiles of patients with Idiopathic Pulmonary Arterial Hypertension (IPAH) admitted to the tertiary care hospital in Aseer region, and to evaluate the altitude effect. Design: A retrospective cohort study. Setting: Aseer Central Hospital. Subjects: All patients admitted with the diagnosis of (IPAH) during the period from January 2001 to ...

BACKGROUND Decline in oxygen uptake efficiency (OUE), especially during exercise, is found in patients with chronic heart failure. In this study we aimed to test the validity and usefulness of OUE in evaluating gas exchange abnormality of patients with idiopathic pulmonary arterial hypertension (IPAH). METHODS We retrospectively investigated the cardiopulmonary exercise test (CPET) with gas e...

INTRODUCTION Despite the prognostic importance of traditionally derived measurements, the significance of right heart catheterization (RHC) remains controversial. Thus, a continued search for hemodynamic markers that define better responsive patients is required. Since, right ventricular failure is the most fatal pathway, right (RVPO) and left (LVPO) ventricular power output are parameters that...

Background—Incidence and prevalence rates for pediatric pulmonary hypertension (PH) and pulmonary arterial hypertension (PAH) are unknown. This study describes the nationwide epidemiological features of pediatric PH in the Netherlands during a 15-year period and the clinical course of pediatric PAH. Methods and Results—Two registries were used to retrospectively identify children (0–17 years) w...

Pulmonary vasoconstriction and vascular remodeling are two major causes for elevated pulmonary vascular resistance and pulmonary arterial pressure in patients with idiopathic pulmonary arterial hypertension (IPAH). An increase in cytosolic free Ca(2+) concentration ([Ca(2+)](cyt)) in pulmonary artery smooth muscle cells (PASMC) is a major trigger for pulmonary vasoconstriction and an important ...