Finally, concomitant NO synthase inhibition enhanced the vasodilator responses to PDE5 inhibition at rest and during BK‐induced vasodilation, but only in females, suggesting that loss of endothelial function may not interfere with (males) or even enhance (females) the pulmonary vasodilator responses to PDE5 in patients with pulmonary hypertension. This evidence concerns the gene PDE5A and pulmonary arterial hypertension.