Insulin,bax Protein Expression And Distribution Of Nnos Immunopositive Nerve Terminals In Mice Islets Of Langerhans After Vagotomy

[Objective]To investigate the effect of vagotomy on the insulin secretion, apoptosis of islet cells and the effect of NO on vagal regulation of insulin secretion by observing insulin,Bax protein expression and the distribution of neuronal nitric oxide synthase (nNOS)-immunoreactive nerve fibers in mice islets of langerhans after vagotomy.[Methods]28 mice were randomly divided into two groups:subdiaphragamatic vagotomy group and control group. Immono-histochemical methods and image analysis technique were used to detect the insulin, Bax protein expression and the expression of nNOS-immunoreactive nerve fibers in mice islets of langerhans at the 3,5,7 and 14 days after vagotomy.[Results]Insulin protein were observed in cytoplasm of islet cells. Most positive insulin cells in the islet dyed brown were beta cells. Image analysis of islet immunocytochemistry showed that total density of insulin positive cells in experiment group were significantly lower than the control group.Bax protein were also expressed in the cytoplasm of the islets cells both of the experiment group and control groups. Image analysis of islet immunocytochemistry showed that the Bax protein expression in islets had increased significantly, compared with control group,nNOS-immunoreactive nerve fibers were observed in the pancreas of two groups mice, and they were mainly located around the islet or in-depth inside, showing dendritic or rosary-like, distributing into the beam line. After vagotomy, the distribution density of nNOS-immunoreactive nerve fibers in islets were significantly decreased compared with control group.[Conclusion]Vagus nerve plays a important role of insulin secretion.High expression of Bax gene after vagotomy indicated that the vagus nerve were involved in regulating islet cell apoptosis.Nitric oxide synthase(nNOS) nerve endings in the pancreas come mainly from the vagus nerve. Partial fibers probably comes from nodose ganglion. That prompts NO is secretion of one of the main neurotransmitters to adjust the islet.