Study On The Tissue Structure And Mucosal Immunity-associated Cells In Abomasum Of The Yak

Yak is unique animal species in china,alpine meadow for food.Providing irreplaceable life material and production material for local nomads,which is the important stockbreeding economy pillar in local.Gastrointestinal mucosa is not only the animal digestion and absorption of nutrients place,but also have immune barrier function. And stomach is an important part of the digestive system.In order to reveal the tissue structure and the distribution and number changes of abomasum mucosal immunity-associated cells in the yak.The tissue structure and intraepithelial lymphocytes, plasma cells and mast cells of abomasum in the yak were investigated with histochemical method, the scion image software analysis techniques method and the electron microscope technique.The results show that there are mucousmembrane, submucosa, tunica muscularis and serosa in the abomasum of yak. The gastric pit(Pyloric gland region275.2±59.8Μm,Fundus gland region144.1±52.9μm,Cardiac gland region143.9±41.4μm) is deepest in the pyloric gland region of abomasum,and this glandular region has also the longest gland(Pyloric gland region827.4±114.71μm,Fundus gland region721.1±120.8μm,Cardiac gland region624.4±137.1μm) and the thickest muscular layer(Pyloric gland region96.1±17.8μm,Fundus gland region44.1±8.9μm,Cardiac gland region25.4±9.1μm). The thickness of muscular and glands length in each glandular region of abomasum are significantly different (P<0.01). The gastric pit of the pylorus gland region is significantly different (P<0.01) with the fundus gland region,and it has also significantly difference compared with the cardiac gland region, but the gastric pit of the fundus gland region is quite similar(P>0.05) to the cardiac gland region.The number of intraepithelial lymphocyte(Fundus gland region2.7±1.8, Cardiac gland region2.6±1.7, Pyloric gland region2.1±1.6) and plasma cell(Cardiac gland region5.7±2.5, Fundus gland region5.1±1.3, Pyloric gland region4.5±2.1) in each glandular region of abomasum are not significantly different (P>0.05).The number of the mast cells between the fundus gland region(26.4±3.3) and the pyloric gland region (20.7±5.0) are significantly different(P<0.01), the fundus gland region has most mast cells, and the pyloric gland region has the lest mast cells, but both of them are similar to the cardia gland region(23.3±4.4)(P>0.05). There are a lot of diffuse lymphatic cells and solitary lymphoid nodules in the lamina propria of abomasum. In the electron microscope, gastric pit columnar epithelial cells are aligned tightly. There are lots of mucous cells in the lamina propria of pylorus gland region, these cells are tall columnar or cone shape, their nucleu are located basally part of the cell,there are the high electrons density particles are gathered in the top of these cells. There are a large number of parietal cells and chief cells in the fundus gland region and cardiac gland region.Plasma cells are circular or elliptical, the chromatin is distributed along the nuclear membrane,cytoplasms are richer in endoplasmic reticulum;Mast cells are elliptical, there are strong electron density particles in its cytoplasm(metachromatic granule).The tissue structure of abomasum in the yak and other ruminant animals basic similar, but each layer has its distinct characteristic. Each gland area of abomasum in the yak are inherent layers with a lot of dispersion lymphocytes and isolated lymphatic summary, make the yak is better than the other abomasum ruminant animals the mucous membrane of the stronger immune function.