迷走神经切断术后小鼠胰岛内神经元型一氧化氮合酶免疫阳性神经末梢的变化

Changes of nNOS immunopositive nerve terminals in Langerhans＇ islets following vagotomy in mice

目的：观察迷走神经切断术后胰岛内神经元型一氧化氮合酶（nNOS）免疫阳性神经末梢分布的变化.方法：将28只小鼠随机分成实验组和对照组,对实验组小鼠行膈下食管迷走神经前、后干切断术,对照组不做任何处理.术后3、 5、 7、 14d分别处死小鼠,取胰冷冻切片,免疫组织化学显色.结果：在实验组和对照组的胰岛内均可观察到nNOS免疫阳性的副交感神经节和神经末梢存在,神经末梢在胰岛周围或深入内部,呈树枝状或念珠状分布,大多成束走行.迷走神经切断后小鼠胰内胰岛nNOS免疫阳性神经末梢的分布密度明显低于正常对照组.结论：胰岛内nNOS免疫阳性神经末梢与迷走神经存在较大的相关性,提示NO是副交感神经调节胰岛分泌的主要神经递质之一.

Objective： To investigate the distribution of neuronal nitric oxide synthase （nNOS）-immunoreactive nerve fibers in the islet of vagotomized mice. Methods： Mice were randomly divided into two groups： subdiaphragarnatic vagotomy group and control group（n= 14）. Immunohistochemical method was used to detect the expression of nNOS-immunoreactive nerve fibers in the pancreas of mice on 3, 5, 7, 14 days after vagotomy. Results： nNOS-immunoreactive nerve fibers were found in the pancreas of two groups mice, and they were mainly distributed around the islet or in-depth inside, showing dendritic or rosary-like, distributing into the beam line. The density of nNOS-immunoreactive nerve fibers in islets significantly decreased after vagotomy, compared with the control group. Conclusion： nNOS nerve endings in the pancreas come mainly from the vagus nerve, suggesting that NO is one of the main neurotransmitters to adjust the islet.