磷酸二酯酶在C型钠尿肽抑制大鼠胃窦平滑肌自发性收缩运动中的作用

Effects of phosphodiesterase on C type natriuretic peptide for inhibiting spontaneous contraction of rat's antral smooth muscle

[目的]观察磷酸二酯酶(PDE)在C型钠尿肽(CNP)抑制大鼠胃窦平滑肌自发性收缩运动中的作用.[方法]制作离体大鼠胃窦环行平滑肌条灌流模型,给予CNP及PDE非选择性抑制剂IBMX后观察胃窦平滑肌自发性收缩运动的变化,并利用ELISA法测定灌流液中环磷酸腺苷(cAMP)和环磷酸鸟苷(cGMP)含量.[结果]CNP可明显抑制大鼠胃窦平滑肌的收缩,经CNP作用后cAMP及cGMP含量均明显增高(P<0.05);经PDE非选择性抑制剂IBMX作用后,CNP对胃窦平滑肌自发性收缩运动的抑制作用明显减弱(P<0.01),给予PDE非选择性抑制剂IBMX作用同时给予CNP,cGMP含量明显增高(P<0.01),但cAMP水平无明显改变(P>0.05).[结论]在胃窦平滑肌组织,经CNP作用后生成的cGMP可通过调节PDE从而提高胃组织中cAMP水平,提示PDE参与CNP对胃窦平滑肌自发性收缩运动的抑制效应.

OBJECTIVETo observe the effects of phosphodiesterase（PDE）on C type natriuretic peptide（CNP）for inhibiting spontaneous contraction of rat＇s antral smooth muscle.METHODSPerfusion model of rat＇s gastric antrum circular smooth muscle was established in vitro,and after treated with the CNP and non-selective PDE inhibitor IBMX,the changes of spontaneous contraction of rat＇s antral smooth muscle were observed,and the contents of cGMP and cAMP in perfusate were detected by ELISA.RESULTSthe CNP inhibited significantly the contraction of rat＇s antral smooth muscle,and the contents of cGMP and cAMP after treated with the CNP were significantly increased（P〈0.05）.After treated with the IBMX,the inhibitory effect of CNP for spontaneous contraction of rat＇s antral smooth muscle was significantly weakened（P〈0.01）,and after treated with the IBMX and CNP,the content of cGMP was significantly increased（P〈0.01）,but it was no significant change on concentration of cAMP（P〈0.05）.CONCLUSION That cGMP treated with CNP could increase the content of cAMP in gastric tissue by adjusting the PDE indicates that the PDE involves in inhibitory effect of CNP for spontaneous contraction of rat＇s antral smooth muscle.