Comparison of small intestinal mucosal structure and mucosal immunity-associated cells between Tibetan antelopes and Tibetan sheep

AIM: To compare the characteristics of small intestinal mucosal structure and mucosal immunity-associated cells between Tibetan antelopes and Tibetan sheep.METHODS: The morphological characteristics of small intestinal mucosal structure were observed under light microscope and electron microscope.The numbers of intraepithelial lymphocytes(IELs),goblet cells(GCs) and mast cells(MCs) in different parts of small intestine were also analyzed by the techniques of histological/histochemical methods and the Scion Image software between Tibetan antelopes(n=5) and Tibetan sheep(n=5).RESULTS: The length of small intestine villi and the ratio of villus length to crypt depth(V/C value) of the Tibetan antelopes were significantly higher than those of the Tibetan sheep(P0.05).The length of the villi in duodenum,jejunum and ileum of the Tibetan antelopes was higher than that of the Tibetan sheep by 77.25%(P0.05),63.61%(P0.05) and 35.38%(P0.05),respectively,while V/C the ratio of villus length to crypt depth(V/C value) of duodenum,jejunum and ileum in Tibetan antelopes was higher than that in the Tibetan sheep by 65.63%(P0.05),20.08%(P0.05) and 35.68%(P0.05),respectively.The thickness of intestinal mucosa in the Tibetan antelopes was significantly greater than that in the Tibetan sheep(P0.05).No significant difference of intestinal muscle thickness between the Tibetan antelopes and the Tibetan sheep was observed(P0.05).The numbers of GCs and MCs in different parts of small intestine in the Tibetan antelopes were obviously higher than those in the Tibetan sheep(P0.05).The number of GCs in duodenum,jejunum and ileum in the Tibetan antelopes were higher than that in the Tibe-tan sheep by 12.84%(P0.05),49.88%(P0.05) and 5.58%(P0.05),respectively,while the number of MCs in duodenum,jejunum and ileum in the Tibetan antelopes was higher than that in the Tibetan sheep by 0.22%(P0.05),6.04%(P0.05) and 160.80%(P0.05),respectively.However,the number of IELs in different parts of small intestine in the Tibetan antelopes was significantly lower(P0.05) than that in the Tibetan sheep.The number of IELs in duodenum,jejunum and ileum in the Tibetan antelopes was lower than that in the Tibetan sheep by 35.04%(P0.05),52.85%(P0.05) and 52.82%(P 0.05),respectively.CONCLUSION: The functions of small intestinal digestion and absorption in Tibetan antelopes are stronger than those in Tibetan sheep.The small intestinal mucosal barrier function of Tibetan antelopes is greater than that of Tibetan sheep.The GCs and MCs in Tibetan antelopes play an important role in intestine mucosal immune defenses,while the IELs play the main role in intestine mucosal defensive barrier in Tibetan sheep.