Sildenafil Citrate 25mg x 30ml, buy liquid Sildenafil Citrate
To investigate further the mechanisms of action of sildenafil, a highly selective and potent inhibitor of type 5 cGMP phosphodiesterase (PDE5) that has proved effective in the treatment of erectile dysfunction, by assessing its effect on the in vitro formation of cGMP and cAMP in the corpus cavernosum of the rabbit.
Materials and methods
Male New Zealand White rabbits (2.5 kg) were killed and their penises rapidly excised, cut into segments and pooled. Penile segments were then incubated with various concentrations of sildenafil or papaverine. The formation of cGMP was stimulated with increasing concentrations of sodium nitroprusside (SNP) and the cGMP and cAMP concentrations measured by radioimmunoassay. Responses were compared to those obtained with papaverine, which is used therapeutically as an erectogen.
In the presence or absence of SNP, sildenafil increased cGMP concentrations in rabbit penile tissue with increasing dose; the increase was greatest (about 28-fold) when cGMP was stimulated with SNP (up to 10 μmol/L). At all stimulatory concentrations of SNP, the effective concentrations for 50% stimulation (EC50 ) of sildenafil were 430–520 nmol/L. Concentrations of cAMP were unaltered by sildenafil. Papaverine enhanced cGMP formation in response to SNP, but at much higher concentrations than did sildenafil (≥10 μmol/L).
Sildenafil specifically increases cGMP levels in rabbit corpora cavernosa; the increase is greater in the presence of SNP indicating that, in vivo, sildenafil may enhance erection by the augmentation of nitric oxide-mediated relaxation pathways. The erectogenic effect of sildenafil is mediated by a specific enhancement of cGMP accumulation in the corpus cavernosum, consistent with the known activity of sildenafil as a potent and highly selective inhibitor of cGMP-specific PDE.
Terms: This product is intended for laboratory research use only. Please read all the terms and conditions of use before considering placing and order.
WARNING This product is a very potent chemical. This product is NOT for human use and can be harmful if ingested. This product is for research/laboratory use only. This product is NOT in a sterile solution and is NOT to be injected. This product should only be handled by licensed, qualified professionals. This product is not a drug, food, or cosmetic and should not be misbranded, misused or mislabeled as a drug, food or cosmetic.
The latter article is intended for educational / informational purposes only. THIS PRODUCT IS INTENDED AS A RESEARCH CHEMICAL ONLY. This designation allows the use of research chemicals strictly for in vitro testing and laboratory experimentation only. Bodily introduction of any kind into humans or animals is strictly forbidden by law.