粉防己碱对离体新西兰白兔阴茎海绵体cAMP和cGMP水平的影响

Effects of tetrandrine on cAMP and cGMP levels in rabbit corpus carvernosum in vitro

目的探讨粉防己碱(Tet)对离体新西兰白兔阴茎海绵体组织中环磷酸腺苷(cAMP)和环磷酸鸟苷(cGMP)水平的影响,以进一步阐明其舒张阴茎海绵体组织的作用机制。方法采用^(125)I放射免疫测定法,观察Tet对离体新西兰白兔阴茎海绵体组织中cAMP和cGMP水平的影响。结果家兔阴茎海绵体组织中cAMP基础含量为(5.67±0.97)pmol/mg。Tet能直接浓度依赖性地升高阴茎海绵体组织中cAMP的含量(P＜0.05),而腺苷酸环化酶抑制剂(MDL-12,330A)对Tet升高的cAMP水平没有抑制作用(P＞0.05)。对cAMP激发剂前列腺素E_1(PGE_1)诱导产生的阴茎海绵体组织中cAMP水平,Tet也具有浓度依赖性升高作用(P＜0.05)。家兔阴茎海绵体组织中cGMP基础含量为(0.44±0.09)pmol/mg。无论是否存在鸟苷酸环化酶抑制剂(ODQ),Tet对阴茎海绵体组织中cGMP的含量均没有影响(P＞0.05)。对cGMP激发剂硝普钠(SNP)诱导产生的阴茎海绵体组织中cGMP水平,Tet也没有任何影响(P＞0.05)。结论Tet可能是通过抑制磷酸二酯酶活性而增加阴茎海绵体组织中cAMP的含量,这是Tet松弛阴茎海绵体组织的作用机制之一。

Objective To further investigate the relaxation mechanisms of tetrandrine on rabbit＇s corpus carvemosum tissue in vitro. Methods The effects of Tot on the concentration of cyclic adenosine monomphsopate （cAMP） and cyclic guanosine monomphsopate （cGMP） in rabbit＇s corpus carvernosum tissue were recorded by means of ^125I radioimmunoassay. Results The basal concentration of cAMP in rabbit＇s corpus carvernosum tissue is （5.67±0.97） pmol/mg. Tot increased cAMP concentrations directly in a concentration-dependent manner （P〈0.05）, and this effect couldn＇t be inhibited by adenylate cyclase inhibitor （MDL-12, 330A） （P〉0.05）. The accumulation of cAMP to PGE1 （a stimulator of cAMP） can also be augmented by Tot in a concentration-dependent manner （P〈0.05）.The basal concentration of cGMP in rabbit＇s corpus carvernosum tissue is （0.44±0.09）pmol/mg. Tot didn＇t affect any concentration of cGMP in corpus carvernosum tissue in the presence or in the absence of a guanylate cyclase inhibitor （ODQ） （P〉0.05）. Tet also didn＇t enhance SNP （a stimulator of cGMP）-induced cGMP production （P〉0.05）. Conclusion Tot can enhance the concentration of cAMP in rabbit＇s corpus carvernosum tissue by inhibiting PDEs activities. This may be one of the relaxation mechanisms of Tot on rabbit corpus carvernosum tissue.