The endothelin system in pulmonary hypertension

Area of Science:

• Cardiovascular Research
• Pulmonary Medicine
• Vascular Biology

Background:

• Pulmonary hypertension (PH) arises from diverse conditions affecting pulmonary circulation.
• Vascular endothelial dysfunction, characterized by imbalanced vasodilating/vasoconstrictive forces, is a key factor in PH development.
• Endothelin-1 (ET-1) overproduction is implicated in PH pathogenesis, with the lungs being a primary site for its production and clearance.

Purpose of the Study:

• To systematically review the pathogenic role of the endothelin (ET) system in PH development.
• To examine the rationale behind preclinical and clinical trials using ET-receptor antagonists for PH treatment.

Main Methods:

• Review of animal models of PH demonstrating elevated plasma ET-1 levels and increased lung tissue ET expression.
• Evaluation of studies using selective ETA and dual ETA-ETB receptor antagonists in preclinical PH models.
• Analysis of recent clinical trials involving ET-receptor antagonists in patients with pulmonary arterial hypertension.

Main Results:

• Animal models consistently show elevated ET-1 levels and increased lung ET expression in PH.
• Preclinical studies confirm ET-1's contribution to increased pulmonary vascular tone, medial hypertrophy, and right ventricular hypertrophy.
• Clinical trials demonstrate the therapeutic efficacy of ET-receptor antagonists in human pulmonary arterial hypertension.

Conclusions:

• The endothelin system plays a significant pathogenic role in the development of pulmonary hypertension.
• ET-receptor antagonists represent a validated therapeutic strategy for pulmonary hypertension, including pulmonary arterial hypertension.