Distribution of 5-hydroxytryptamine,Ghrelin or Glucagon-like Peptide-1 Immunopositive Cells in the Gastrointestinal Tract of Meihua Pig

In order to analyze the distributions and densities of endocrine cells in the gastrointestinal tract of Meihua pig (an elite native breed of Guangdong province, China), 6 healthy piglets weaned at 30 days of age were fed with the same diet till 65 days of age. At 65 days of age, different sections of the gastrointestinal tract of each piglet were collected, and the features and densities of 5-hydroxytryptamine (5-HT), ghrelin and glucagon-like peptide-1 (GLP-1) immunopositive cells were detected by immunohistochemistry. The results showed that the 5-HT positive cells distributed at the epithelial layer throughout the intestinal tract (duodenum, jejunum, ileum and colon) with a variety of features (e.g. cone, round, spindle), and they could be classified into either open-shape or closed-shape type, the density of 5-HT positive cells in duodenum was highest; The ghrelin positive cells were located along the gastrointestinal tract (gastric glands, pylorus, duodenum and jejunum) with both open-shape and closed shape, and its density decreased along the tract with most cells in gastric glands; The GLP-1 positive cells were observed along the intestinal tract, but its density increased from duodenum to ileum and then decreased in colon. This study might provide supporting data for further study of the gastrointestinal physiology of Meihua pig.