Modulation of endothelin receptors in the failing right ventricle of the heart and vasculature of the lung in human pulmonary arterial hypertension

LIFE SCIENCES

卷:118

Article

Kuc, Rhoda E.¹  Carlebur, Myrna¹  Maguire, Janet J.¹  Yang, Peiran¹  Long, Lu²  Toshner, Mark²  Morrell, Nicholas W.²  Davenport, Anthony P.¹ 

[1] Addenbrookes Hosp, Clin Pharmacol Unit, Cambridge CB2 0QQ, England

[2] Addenbrookes Hosp, Dept Med, Cambridge CB2 0QQ, England

关键词: Pulmonary arterial hypertension;    Endothelin;    FR139317;    Radioligand binding;    Affinity constant;    Receptor density;   

DOI  :  10.1016/j.lfs.2014.02.020

来源: Elsevier

【 摘 要 】

Aims: In pulmonary arterial hypertension (PAH), increases in endothelin-1 (ET-1) contribute to elevated pulmonary vascular resistance which ultimately causes death by right ventricular (RV) heart failure. ET antagonists are effective in treating PAH but lack efficacy in treating left ventricular (LV) heart failure, where ETA receptors are significantly increased. The aim was to quantify the density of ETA and ETB receptors in cardiopulmonary tissue from PAH patients and the monocrotaline (MCT) rat, which recapitulates some of the pathophysiological features, including increased RV pressure. Main methods: Radioligand binding assays were used to quantify affinity, density and ratio of ET receptors. Key findings: In RV from human PAH hearts, there was a significant increase in the ratio of ETA to ETB receptors compared with normal hearts. In the RV of the MCT rat, the ratio also changed but was reversed. In both human and rat, there was no change in LV. In human PAH lungs, ETA receptors were significantly increased in the medial layer of small pulmonary arteries with no change detectable in MCT rat vessels. Significance: Current treatments for PAH focus mainly on pulmonary vasodilatation. The increase in ETA receptors in arteries provides a mechanism for the beneficial vasodilator actions of ET antagonists. The increase in the ratio of ETA in RV also implicates changes to ET signalling although it is unclear if ET antagonism is beneficial but the results emphasise the unexploited potential for therapies that target the RV, to improve survival in patients with PAH. (C) 2014 The Authors. Published by Elsevier Inc.

【 授权许可】

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