3',5'-Cyclic-GMP Phosphodiesterases/metabolism; Acetic Acid/pharmacology; Acetylcholine/pharmacology; Animals; Carrageenan/pharmacology; Cholinergic Agents/metabolism; Cholinesterase Inhibitors/pharmacology; Cyclic GMP/metabolism; Cyclic Nucleotide Phosphodiesterases, Type 5; Dose-Response Relationship, Drug; Drug Combinations; Enzyme Inhibitors/pharmacology; Female; Guanylate Cyclase/antagonists & inhibitors; Hyperalgesia/chemically induced; Male; Methylene Blue/pharmacology; Mice; NG-Nitroarginine Methyl Ester/pharmacology; Neostigmine/pharmacology; Nitric Oxide/metabolism; Nitric Oxide Synthase/antagonists & inhibitors; Pain/chemically induced; Pain Measurement; Phosphodiesterase Inhibitors/pharmacology; Piperazines/therapeutic use; Purines; Rats; Sulfones