Carrier N, Connat J L
Laboratoire d'Anatomie et Physiologie Comparées, Université de Genève, Switzerland.
Gen Comp Endocrinol. 1995 Nov;100(2):197-210. doi: 10.1006/gcen.1995.1149.
The wall of the rat common bile duct (CBD) consists of several epithelial ducts embedded in connective tissue which contains some regions with cells weakly stained by an antibody against alpha smooth muscle actin. The hepatic side (HS) is more vascularized than the duodenal side (DS). Calcitonin gene-related peptide (CGRP)-like immunoreactivity is present in nerve fibres penetrating deeply into the CBD wall. On whole-mount preparations, CGRP innervation is mainly associated with blood vessels in the HS, whereas it forms a wide meshed network independent of vasculature in the DS. Abundance of CGRP innervation was compared between both sexes and at different ages. No differences were found in the total number of fibres between males and females except at 4 months of age, when males had statistically more abundant innervation than females. However, during aging, while the abundance of innervation (fibers/mm) remained stable in both HS and DS in females, it significantly decreased in males. Autoradiography demonstrated the presence of 125I-CGRP binding sites in the rat CBD. In vitro, 30% of HS strips showed spontaneous rhythmic contractions but all the strips (autocontractile or not) contracted dose dependently in response to acetylcholine (Ach) or substance P (SP). However, DS strips were neither autocontractile nor responsive to Ach or SP. Perfusion of all strips with 10(-7) M CGRP produced no effects nor influenced Ach- or SP-induced contractions.
大鼠胆总管（CBD）壁由嵌入结缔组织的几条上皮导管组成，结缔组织中有些区域的细胞被抗α平滑肌肌动蛋白抗体弱阳性染色。肝侧（HS）比十二指肠侧（DS）血管化程度更高。降钙素基因相关肽（CGRP）样免疫反应性存在于深入穿透胆总管壁的神经纤维中。在整装标本上，CGRP神经支配主要与肝侧的血管相关，而在十二指肠侧则形成一个独立于脉管系统的宽网状网络。比较了两性和不同年龄组的CGRP神经支配丰度。除4月龄时雄性的神经支配在统计学上比雌性更丰富外，雄性和雌性之间的纤维总数没有差异。然而，在衰老过程中，雌性肝侧和十二指肠侧的神经支配丰度（纤维数/毫米）保持稳定，而雄性则显著下降。放射自显影显示大鼠胆总管中存在125I-CGRP结合位点。在体外，30%的肝侧条带表现出自发性节律性收缩，但所有条带（无论是否自动收缩）对乙酰胆碱（Ach）或P物质（SP）均呈剂量依赖性收缩。然而，十二指肠侧条带既无自动收缩性，也对Ach或SP无反应。用10^(-7)M CGRP灌注所有条带均无作用，也不影响Ach或SP诱导的收缩。
