Department of Physiology, Shandong University School of Medicine, Jinan 250012, People's Republic of China.
Pflugers Arch. 2010 Nov;460(6):1063-71. doi: 10.1007/s00424-010-0880-7. Epub 2010 Oct 5.
The aim of the present study was to investigate the effect of oxytocin (OT) on duodenum motility in rats and the possibility that cholecystokinin (CCK) was involved in this process. The isometric contraction of longitudinal muscle strips of duodenum was monitored by polygraph. ELISA was used to measure the concentration of CCK and OT in duodenum. CCK mRNA was assayed by RT-PCR. Oxytocin receptor (OTR) and CCK in duodenum were located by immunohistochemistry and immunofluorescence staining. OT (10⁻⁵ and 10⁻⁶ M) inhibited the spontaneous contraction of the muscle strips. On the contrary, atosiban (OT receptor antagonist), lorglumide (CCK₁ receptor antagonist), and tetrodotoxin (TTX, blocker of voltage-dependent Na(+) channel on nerve fiber) excited the contraction. The inhibitory effect of OT on duodenal motility was reversed by pretreatment of atosiban, lorglumide, or TTX. Exogenous OT did not influence the expression of OT mRNA in duodenum but increased the concentration of CCK in the culture medium of the cells isolated from longitudinal muscle myenteric plexus. The OTR and CCK were co-expressed in the neurons of the myenteric plexus in duodenum. We concluded that OT inhibited the contraction of the LD spontaneous contraction of rats in vitro. This effect was mediated by the CCK released from the neurons of the myenteric plexus in duodenum.
本研究旨在探讨催产素（OT）对大鼠十二指肠运动的影响，以及胆囊收缩素（CCK）是否参与这一过程。通过多导记录仪监测十二指肠纵肌条的等长收缩。采用 ELISA 法测定十二指肠中 CCK 和 OT 的浓度。采用 RT-PCR 法测定 CCK mRNA。通过免疫组织化学和免疫荧光染色检测十二指肠中的催产素受体（OTR）和 CCK。OT（10⁻⁵ 和 10⁻⁶ M）抑制肌肉条的自发性收缩。相反，阿托西班（OT 受体拮抗剂）、洛格卢米德（CCK₁受体拮抗剂）和河豚毒素（TTX，神经纤维电压依赖性 Na(+)通道阻断剂）兴奋收缩。阿托西班、洛格卢米德或 TTX 的预处理可逆转 OT 对十二指肠运动的抑制作用。外源性 OT 不影响十二指肠中 OT mRNA 的表达，但增加了从纵肌肌间神经丛分离的细胞培养基中 CCK 的浓度。OTR 和 CCK 在十二指肠肌间神经丛的神经元中共同表达。我们得出结论，OT 抑制了体外大鼠 LD 自发性收缩的收缩。这种作用是由来自十二指肠肌间神经丛的神经元释放的 CCK 介导的。
Zotero 插件