Effects of Phosphodiesterase 5 Inhibitor on Pulmonary Vascular Reactivity in the Fetal Lamb

Although sildenafil induces a transient pulmonary vasodilation, it mediates a sustained change in vascular reactivity, especially to birth-related stimuli in the ovine fetal lung. These data suggest that PDE5 is involved in the regulation of pulmonary vascular reactivity during the perinatal period and may potentiate birth-related pulmonary vasodilator stimuli.