Expression and Localization of VIP in Different Segments of Pigeon Intestine

In order to further investigate the structural characteristic of pigeon intestine, the microstructure of each part of intestine was analyzed by HE staining, and its vasoactive intestinal peptide (VIP) was detected by immunohistochemistry staining and RT-qPCR. In present results, the intestinal mucosa epithelium is a single layer of columnar epithelium, other structures are relatively complete, and the intestinal villi and glands are distinct in each part of intestine. The localization of VIP is extensive in the intestinal wall, but most typical in the lamina propria and muscular layer; VIP in mucosal epithelium is mainly distributed within goblet cells. The distribution of VIP is stronger in the duodenum than in other parts, followed by the rectum, ileum, and jejunum. The lamina propria, muscular layer and serosa always contain VIP nerve fibers with deep staining. Unexpectedly, the results of RT-qPCR showed that the expression level is consistent with that of immunohistochemical detection. It is indicated VIP probably participate in the functional regulation of pigeon intestine as a key role and mediate the neuroendocrine and mucosal immune system as an information molecule due to the high expression of VIP. It will provide the basis for clarifying the biological function of VIP in pigeons.