一氧化氮与胆囊收缩素对犬Oddi括约肌的作用

目的 探讨一氧化氮和胆囊收缩素(CCK)在犬Oddi括约肌运动调节中的作用.方法 测定正常状态及注射CCK、硝普钠、一氧化氮合酶(NOS)抑制剂N-硝基-L-精氨酸甲酯(L-NAME)时,犬Oddi括约肌的基础压、时相收缩频率、时相收缩幅度;免疫组织化学染色法检测犬Oddi括约肌上NOS阳性神经元的表达情况.计量资料的比较采用t检验.结果 注射0、20 ng/kg CCK后,犬Oddi括约肌基础压、时相收缩频率、时相收缩幅度分别为(27±10)mm Hg(1 mm Hg=0.133 kPa)、(10±3)次/min、(32±8)mm Hg和(61±14)mm Hg、(64±21)次/min、(44±15)mm Hg;注射100 ng/kg CCK后产生最大抑制作用和最大兴奋作用时,犬Oddi括约肌基础压、时相收缩频率、时相收缩幅度分别为(77 +31)mm Hg、(69±18)次/min、(79±14)mm Hg和(140±21)mm Hg、(129±25)次/min、( 173±63)mm Hg.胆总管滴注硝普钠后,犬Oddi括约肌基础压、时相收缩幅度均下降(t =3.706,5.183,P＜0.05).而注射L-NAME后,犬Oddi括约肌基础压、时相收缩幅度均升高(t=5.859,3.588,P＜0.05).结论 20 ng/kg生理剂量的CCK可舒张犬Oddi括约肌,大剂量CCK可兴奋犬Oddi括约肌;一氧化氮对犬Oddi括约肌发挥舒张效应,此效应可能在CCK的抑制通路中发挥重要作用.

Effects of nitric oxide and cholecystokinin on the sphincter of Oddi of dogs

Objective To investigate the effects of nitric oxide (NO) and cholecystokinin (CCK) on the regulation of the motility of sphincter of Oddi (SO).Methods The basal pressure,action rate and contraction range of the SO were examined before and after the injection of CCK,sodium nitroprusside (SNP) and NG-nitroL-argininemethyl ester hydrochloride (L-NAME).The expression of neurons with positive expression of NO synthase was detected by immunohistochemical staining.The measurement data were analyzed by using the t test.Results The basal pressure,contraction rate and contraction range of the SO were (27 + 10)mm Hg (1 mm Hg =0.133 kPa),( 10 ± 3 ) times/minute and (32 + 8 ) mm Hg before injection of CCK,and (61 + 14) mm Hg,(64 +21 ) times/minute,(44 ± 15 ) mm Hg after injection of CCK of 20 ng/kg.After injection of CCK of 100 ng/kg,the basal pressure,contraction range and contraction rate of the SO were (77 ± 31 )mm Hg,(69 ± 18 ) times/minutes,(79 + 14) mm Hg when the inhibition effect of CCK reached peak,and were ( 140 ± 21 ) mm Hg,( 129 ± 25 )times/minutes,( 173 ± 63 ) mm Hg when the excitatory effect of CCK reached peak.After injection of SNP into the common bile duct,the basal pressure,contraction range and contraction rate of the SO decreased significantly ( t =3.706,5.183,P ＜ 0.05),while the 3 indexes increased significantly after injection of SNP (t =5.859,3.588,P ＜O.05).Conclusion Different from physiological dose (20 ng/kg) of CCK,large dose of CCK enhances motility of SO intensively.NO relaxes SO,which may play an important role in the inhibitor pathway of CCK.