TY - JOUR T1 - Sildenafil decreases the contractile response to serotonin (5HT) in pulmonary arteries from patients with idiopathic pulmonary fibrosis (IPF) and pulmonary hypertension (PH) JF - European Respiratory Journal JO - Eur Respir J VL - 44 IS - Suppl 58 SP - P2344 AU - Gustavo Juan AU - Javier Milara AU - Jose Luis Ortiz AU - Juan Escriva AU - Mercedes Ramon AU - Estrella Fernandez AU - Julio Cortijo Y1 - 2014/09/01 UR - http://erj.ersjournals.com/content/44/Suppl_58/P2344.abstract N2 - Introduction: PH in IPF portends a poor prognosis. Although included in WHO class 3 (hypoxia-associated PH), it has been postulated that shares pathogenic features with IPH.Aims: To study in vitro the pulmonary artery reactivity from patients with PH complicating IPF, and how the PDE5 inhibitor sildenafil modulates this vascular reactivityMethods: Peripheral pulmonary arteries were obtained from: 1) Patients with IPF with PH and without PH who underwent lung transplantation, 2) Patients with PH without IPF transplanted and 3) Controls. We studied the cumulative increasing relaxant response to sildenafil after maximal contraction with 5-HT, and the inhibitory effect of sildenafil on the contractile response of cumulative doses of 5-HT in the different study population.Results: Sildenafil concentration-dependently relaxed pulmonary arteries from control and IPF patients with similar maximum effect, reaching 41.3±11.6% and 37.2±15.5% of relaxation respectively, but in patients with severe PH, sildenafil only reached a low % relaxation of 5.3±5.4% as occurred with IPF + PH (9.8±9%). In pulmonary arteries from IPF, and with more efficacy in pulmonary arteries from IPF + PH and PH, sildenafil inhibited contraction curves of 5-HT reaching 36.3±4.7%, 24.6±8.6% and 21.2±3.9% of contraction.Conclusions: 1) Sildenafil has a lower relaxant effect on 5-HT pre-contracted arteries from IPF+PH and PH patients compared with normal and IPF pulmonary arteries. 2) Sildenafil dose-dependently inhibited pulmonary artery contraction induced by 5-HT with more efficacy in IPF+PH and PH patients than in IPF patients. ER -