Effects of nitric oxide and cholecystokinin on the sphincter of Oddi of dogs / 中华消化外科杂志

ABSTRACT

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.