胆囊收缩素受体对人食管下括约肌套索纤维和钩状纤维的调节机制

Regulation of cholecystokinin receptors on sling and clasp fibersin the human lower esophageal sphinc-ter

目的探讨人食管下括约肌的套索纤维和钩状纤维对CCK-8和胃泌素-17的反应特点,以及胆囊收缩素受体对两者的调节作用。方法运用离体组织张力测量技术,得出套素纤维和钩状纤维对CCK-8和胃泌素-17的最大收缩效应值(Emax),以及特异性胆囊收缩素受体拮抗剂对 CCK-8的pKB值。结果套索纤维对CCK-8和胃泌素-17产生了较强的浓度依赖性收缩反应 [Emax值:(5．18±0．50)mN／mm2和(4．91±0．95)mN／mm2],而钩状纤维的收缩强度[Emax值: (0．73±0．23)mN／mm2和(0．72±0．14)mN／mm2]显著低于套索纤维(P<0．001;P<0．01)。 CR1409和CR2945对CCK-8引发的套索纤维收缩均产生了浓度依赖性抑制作用,前者的pKB值 (7．51±0．11)大于后者(7．15±0．11)(P<0．05)。结论套索纤维对CCK-8和胃泌素-17刺激的收缩强度显著大于钩状纤维,CCKA受体在其中发挥着更为重要的作用。

Objective To explore the difference in the response to CCK-8 and gastrin-17 developed by the sling and clasp fibers in the human lower esophageal sphincter, and the regulation of choleeystokinin receptors on them, Methods Through in vitro isolated tissue tension detection technique, the Emaxs developed by the sling and clasp fibers to CCK-8 and gastrin-17 was derived. Then the pKB value of competitive selective eholecystokinin receptor antagonists to CCK-8 in the sling fibers was calculated. Results Sling fibers developed significant contraction to CCK-8 and gastrin-17 [Emaxs： （5.18 ± 0.50） mN/ mm^2 and （4.91± 0.95） mN/mm^2] in a concentration-dependent fashion, whereas the responses of the clasp fibers [Emaxs： （0.73 ± 0.23） mN/mm^2 and （0.72 ±0.14） mN/mm^2] were smaller than those of the sling fibers （P 〈 0. 001;P 〈 0.01）. CR1409 and CR2945 inhibited response developed by the sling fibers to CCK-8 in a concentration-dependent fashion, in which PKB value of CR1409 （7.51 ± 0.11 ）was greater than that of CR2945 （7.15 ± 0.11） （P 〈 0.05）. Conclusion The sling fibers develop much more intensive contraction to CCK-8 and gastrin-17 than clasp fibers, in which CCKA receptors play more important roles.