钙离子拮抗剂维拉帕米对人食管下括约肌舒缩的调节机制

Regulation mechanism of contraction and relaxation of human lower esophageal sphincter by calcium antagonist verapamil

目的通过比较钙离子拮抗剂维拉帕米对由乙酰胆碱诱导的人食管下括约肌(LES)套索纤维和钩状纤维肌条收缩的拮抗程度,探讨维拉帕米对LES肌条舒缩的影响。方法应用中上段食管癌患者LES作为研究对象,同时取食管体部和胃底肌条作为对照。分离出食管体部、胃底、套索纤维(sling)和钩状纤维(clasp)肌束,应用离体肌条张力测定技术分别测定维拉帕米(10^(-3) mol/L)对由乙酰胆碱(Ach)(浓度分别为10^(-6)、10^(-5)、10^(-4)、10^(-3)、10^(-2)、10^(-1) mol/L)诱导的4种肌条收缩的拮抗程度。结果食管环行肌组、胃底环形肌组和clasp组加入维拉帕米前后未见肌条收缩水平有明显改变(t=0.896,P=0.372;t=0.331,P=0.741;t=0.324,P=0.747;t=2.294,P=0.023)。sling组加入维拉帕米后,收缩能力下降,收缩水平由(17.0±5.2)g降至(14.7±6.6)g,差异有统计学意义(t=2.294,P=0.023)。结论维拉帕米部分阻滞了LES套索纤维的收缩,从而导致了LES的舒张。

Objective To investigate the effects of calcium antagonist verapamil on the contraction and relaxation of human lower esophageal sphincter （LES） clasp and sling fibers induced by acetylcholine （Ach）. Methods LES was obtained from patients with superior and middle esophageal carcinoma, and muscles of esophageal body and gastric bottom were served as controls. After isolation of muscle bundles of esophageal body, gastric bottom, sling fibers and clasp fibers, in vitro muscle stripe intensity measurement technique was employed to determine the effects of verapamil （10.-3 mol/L） on the contraction and relaxation of these four muscle stripes induced by Ach（10-6 , 10-5 , 10-4, 10-3 , 10-2 and 10-1 mol/L）. Results The contraction of circular muscles of esophageal body and gastric bottom and clasp fibers was not significantly changed after verapamil intervention （t=0. 896, P= 0. 372 ;t= 0. 331, P = 0. 741; t = 0. 324, P = 0. 747）. However, the contraction of sling fibers was significantly decreased from （17.0±5.2） g to （14.7 ± 6.6） g after verapamil intervention （t = 2. 294, P = 0. 023）. Conclusions Verapamil partly blocks the contraction of LES, and results in the relaxation of LES.