Nitric oxide effects are downstream from cAMP which is degraded by PDE4. cAMP increases usually come from g-protein coupled receptors releasing it and then there's a cascade that depending on the cell type may create Nitric oxide. However, nitric oxide is upstream of cGMP metabolically and is degraded by PDE5.
Yes, sorry for the oversight.
> Nitric oxide is not involved in the action of PDE4.
?
Phosphodiesterase type 4 inhibition enhances nitric oxide- and hydrogen sulfide-mediated bladder neck inhibitory neurotransmission https://www.nature.com/articles/s41598-018-22934-1
cAMP Phosphodiesterase Inhibitors Increases Nitric Oxide Production by Modulating Dimethylarginine Dimethylaminohydrolases https://www.ahajournals.org/doi/10.1161/CIRCULATIONAHA.110.9...
PDE4 inhibitors are most likely anti-inflammatory because they affect NO.