OBJECTIVE: To elucidate the expression profile and significance of cholecystokinin-A (CCK-A) receptors in ICLCs in the common bile duct (CBD), as well as the role of CCK in regulating CBD motility through CCK-A receptors on CBD ICLCs.
METHODS: The levels of tyrosine kinase receptor (c-kit) and CCK-A receptors in CBD tissues and isolated CBD cells were quantified using the double immunofluorescence labeling technique. The CCK-mediated enhancement of the movement of CBD muscle strips through CBD ICLCs was observed by a muscle strip contraction test.
RESULTS: Immunofluorescence showed co-expression of c-kit and CCK-A receptors in the CBD muscularis layer. Observations of isolated CBD cells showed that c-kit was expressed on the surface of ICLCs, the cell body and synapse were colored and polygonal, and some cells presented protrusions and formed networks adjacent to the CBD while others formed filaments at the synaptic terminals of local cells. CCK-A receptors were also expressed on CBD ICLCs. At concentrations ranging from 10-6 mol/L to 10-10 mol/L, CCK promoted CBD smooth muscle contractility in a dose-dependent manner. In contrast, after ICLC removal, the contractility mediated by CCK in CBD smooth muscle decreased.
CONCLUSIONS: CCK-A receptors are highly expressed on CBD ICLCs, and CCK may regulate CBD motility through the CCK-A receptors on ICLCs.
目的:阐明胆囊收缩素-A(CCK-A)受体在胆总管(CBD)ICLCs中的表达谱和意义,以及CCK在通过CBDICLC上的CCK-A受体调节CBD运动中的作用。
方法:采用双重免疫荧光标记技术对CBD组织和分离的CBD细胞中酪氨酸激酶受体(c-kit)和CCK-A受体的水平进行定量。通过肌肉条收缩测试观察到CCK介导的CBD肌肉条通过CBDICLC的运动的增强。
结果:免疫荧光显示c-kit和CCK-A受体在CBD肌层共表达。对分离的CBD细胞的观察表明,c-kit在ICLCs表面表达,细胞体和突触是彩色的和多边形的,一些细胞出现突起并在CBD附近形成网络,而另一些细胞在局部细胞的突触末端形成细丝。CCK-A受体也在CBDICLC上表达。在10-6mol/L至10-10mol/L的浓度范围内,CCK以剂量依赖性方式促进CBD平滑肌收缩性。相比之下,ICLC移除后,CCK介导的CBD平滑肌收缩力降低。
结论:CCK-A受体在CBDICLC上高表达,CCK可能通过ICLC上的CCK-A受体调节CBD运动。