Sildenafil reverses O2 constriction of the rabbit ductus arteriosus by inhibiting type 5 phosphodiesterase and activating BK(Ca) channels.
Thébaud B, Michelakis E, Wu XC, Harry G, Hashimoto K, Archer SL. Sildenafil reverses O2 constriction of the rabbit ductus arteriosus by inhibiting type 5 phosphodiesterase and activating BK(Ca) channels. Pediatr Res. 2002 Jul; 52(1):19-24.