摘要
Aim: To further investigate the relaxation mechanism of neferine (NED, a bis-benzylisoquinoline alkaloid extracted (isolated) from the green seed embryo of Nelumbo nucifera Gaertn in China, on rabbit corpus cavernosum tissue in vitro. Methods: The effects of Nef on the concentrations of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) in isolated and incubated rabbit corpus cavernosum tissue were recorded using ^125I radioimmunoassay. Results: The basal concentration of cAMP in corpus cavernosum tissue was 5.67 ± 0.97 pmol/mg. Nef increased the cAMP concentration in a dose-dependent manner (P 〈 0.05), but this effect was not inhibited by an adenylate cyclase inhibitor (cis-N-[2-phenylcyclopentyl]azacyclotridec-1-en-2-amine, MDL-12, 330A) (P 〉 0.05). The accumulation of cAMP induced by prostaglandin Et (PGEt, a stimulator of cAMP production) was also augmented by Nef in a dose-dependent manner (P 〈 0.05). The basal concentration of cGMP in corpus cavernosum tissue is 0.44 ± 0.09 pmol/mg. Nef did not affect this concentration of cGMP, either in the presence or in the absence of a guanyl cyclase inhibitor (1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one, ODQ) (P 〉 0.05). Also, sodium nitroprusside (SNP, a stimulator of cGMP production)-induced cGMP production was not enhanced by Nef (P 〉 0.05). Conclusion: Nef, with its relaxation mechanism, can enhance the concentration of cAMP in rabbit corpus cavernosum tissue, probably by inhibiting phosphodiesterase activity. (Asian JAndro12008 Mar; 10: 307-312)
Aim: To further investigate the relaxation mechanism of neferine (NED, a bis-benzylisoquinoline alkaloid extracted (isolated) from the green seed embryo of Nelumbo nucifera Gaertn in China, on rabbit corpus cavernosum tissue in vitro. Methods: The effects of Nef on the concentrations of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) in isolated and incubated rabbit corpus cavernosum tissue were recorded using ^125I radioimmunoassay. Results: The basal concentration of cAMP in corpus cavernosum tissue was 5.67 ± 0.97 pmol/mg. Nef increased the cAMP concentration in a dose-dependent manner (P 〈 0.05), but this effect was not inhibited by an adenylate cyclase inhibitor (cis-N-[2-phenylcyclopentyl]azacyclotridec-1-en-2-amine, MDL-12, 330A) (P 〉 0.05). The accumulation of cAMP induced by prostaglandin Et (PGEt, a stimulator of cAMP production) was also augmented by Nef in a dose-dependent manner (P 〈 0.05). The basal concentration of cGMP in corpus cavernosum tissue is 0.44 ± 0.09 pmol/mg. Nef did not affect this concentration of cGMP, either in the presence or in the absence of a guanyl cyclase inhibitor (1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one, ODQ) (P 〉 0.05). Also, sodium nitroprusside (SNP, a stimulator of cGMP production)-induced cGMP production was not enhanced by Nef (P 〉 0.05). Conclusion: Nef, with its relaxation mechanism, can enhance the concentration of cAMP in rabbit corpus cavernosum tissue, probably by inhibiting phosphodiesterase activity. (Asian JAndro12008 Mar; 10: 307-312)
基金
Acknowledgment The authors thank Prof. Jia-Ling Wang for kindly supplying the neferine. The technical support from Prof. Bo-Hua Shu is also greatly appreciated. This study was sponsored by the National Natural Science Foundation of China (No. 30471736) and China Postdoctoral Science Foundation (No. 20070410176).