Description
Sildenafil is the first phosphodiesterase 5 (PDE5) inhibitor developed by Pfizer in the United States for the treatment of erectile dysfunction in men. Its commercial name is Viagra. Sildenafil was first entered into clinical research as a 5-phosphodiesterase inhibitor for the treatment of cardiovascular disease, but clinical studies have shown that the effect of sildenafil on cardiovascular disease did not meet the expectations of researchers , and later researchers found that this drug improved the patient's sex life.
Biological Activity
sildenafil mesylate is an inhibitor of cyclic guanosine monophosphate (cgmp)-specific phosphodiesterase type 5 (pde5).pde5 is the predominant phosphodiesterase in the corpus cavernosum. the catalytic site of pde5 degrades cgmp, and pde5 inhibitors can potentiate endogenous increases in cgmp.
Pharmacology
Sildenafil mesylate is the mesylate form of sildenafil and has the same pharmacological effects as sildenafil. Sildenafil is a selective 5-phosphodiesterase inhibitor that enhances nitric oxide-dependent pulmonary vasodilation mediated by cyclic guanosine monophosphate by inhibiting the breakdown of cyclic guanosine monophosphate. In addition to the direct expansion of pulmonary blood vessels, it can also prevent or reverse vascular remodeling.
in vitro
sildenafil mesylate had been identified as a potent pde5 reversible and selective inhibitor. sildenafil enhanced sodium nitroprusside- or transmural electrical stimulation-induced relaxation of precontracted corpus cavernosum muscle strips in organ baths. sildenafil also increased intracellular cgmp concentrations in cultured smooth muscle cells treated with sodium nitroprusside [1].
in vivo
in anesthetized dogs, sildenafil could enhance the erectile function following pelvic nerve stimulation as measured by increased intracavernosal pressure [1].
References
[1] nehra a,colreavy f,khandheria bk,chandrasekaran k. sildenafil citrate, a selective phosphodiesterase type 5 inhibitor: urologic and cardiovascular implications. world j urol.2001 feb;19(1):40-5.
[2] moore ra,edwards je,mcquay hj. sildenafil (viagra) for male erectile dysfunction: a meta-analysis of
