Penile ErectionPenisPriapismMuscle RigidityErectile DysfunctionImpotence, VasculogenicYawningPhosphodiesterase 5 InhibitorsNepetaSulfonesApomorphinePurinesEjaculationAlprostadilPiperazinesPapaverineNitric Oxide Synthase Type ICopulationSulpiridePhosphodiesterase InhibitorsCyclic Nucleotide Phosphodiesterases, Type 5Nitric OxidePenile IndurationDopamine AgonistsElectric StimulationOrgasmLibidoScopolamine HydrobromidePindololMuscle, SmoothNitric Oxide SynthasePressureNG-Nitroarginine Methyl EsterRats, Sprague-Dawley