Research To Number Of Mucosal Immunity-associated Cell And Change Of Digestive Enzyme Activity In Swine With Proliferative Enteritis

Porcine Proliferative Enteritis (PPE) is the contagious infectious disease of adenoma-like hyperplasia in crypt epithelium cells of porcine intestinal mucosa caused by obligate cell's Lawsonia intracellularis. Since the first report by Schwarte and others in 1931, PPE had already spread to main swine production countries of the world at the present time. In 1999, our country had also reported the outbreak, diagnosis, and prevention of the disease. Clinical suspected cases have the tendency of increasing, with a high infection rate in swine herds. The infected swine has a drop of growth rate, and emaciation, so PPE is a kind of worldwide disease with important economical significance, will bring great economic loss to swine industry. To investigate the number of mucosal immunity-associated cell of intestinal mucosal in swine with Proliferative Enteritis, change of distribution, and change of digestive enzyme and alkaline phosphatase activity will have a great significance for the gnosia of the disease.In Experiment 1, using Light Microscope Method to compare the number and distribution change of duodenum, jejunum, ileum mucous membrane lymphocyte, goblet cell, and mast cell of the positive swine and the negative swine after the PCR test. The results show that:(1). Lymphocyte: In duodenum and jejunum mucous membrane epithelium cell of the positive swine, compared with the negative swine, lymphocyte's number in each 100 columnar cells decreased slightly (P> 0.05), ileum the same increased slightly (P> 0.05). Number of lymphocyte in mucous membrane of porcine intestinal mucosa decreased gradually from the positive swine to negative swine. (2). Goblet cell:In duodenum, jejunum and ileum mucous membrane epithelium cell of the positive swine, compared with the negative swine, goblet cell's number in each 100 columnar cells increased significantly (P< 0.05). (3) Mast cell:Mast cell's number in mucosal lamina propria of the jejunum and ileum in positive swine, compared with the negative swine, decreased significantly (P< 0.05)In Experiment 2, using Enzymatic Reaction Method to compare the activity change in pancreas, duodenum, jejunum, ileum amylase, trypsin, lipase, and alkaline phosphatase of the positive swine and the negative swine after the PCR test. The results show that:(1). The activity of intestine amylase:Compared with the negative swine, the activity of amylase in pancreas, duodenum, jejunum and ileum of the positive swine all decreased (P> 0.05). (2). The activity of the trypsin in the intestine:Compared with the negative swine, the activity of the trypsin in pancreas, duodenum, jejunum, and ileum of the positive swine all decreased, among them the difference of comparison in pancreas and duodenum is slightly (P> 0.05), and that in jejunum and ileum is significantly (P< 0.05). (3). The activity of the lipase in the intestine:Compared with the negative swine, the activity of the lipase in pancreas, duodenum, jejunum and ileum of the positive swine all decreased (P> 0.05). (4). The activity of the alkaline enzymes in the intestine:Compared with the negative swine, the activity of the alkaline enzymes in pancreas, duodenum, jejunum, and ileum of the positive swine all decreased, among them the difference of comparison in pancreas, duodenum, and jejunum is slightly (P> 0.05), and that in ileum is significantly (P< 0.05), the activity of the alkaline enzymes in pancreas of the positive swine and the negative swine is extremely low.Conclusion:the number decrease of the lymphocyte and the mast cell causes the protection function of the intestine's mucosal barrier to decrease, so as to make the swine easily be infected by Lawsonia intracellularis and become the Porcine Prolierative Enteritis. The shedding of the infected swine's epithelium cell in intestine's mucous membrane stimulates the prolieration of the goblet cell, and in the circumstances of the imperfect immune function of the intestine, the goblet cell plays a certain function of immune function, and at the same time produces large number of three-phyllode protein. Collaborated with the cytokine and growth factor, goblet cell makes the healing process of the epithelium cell accelerated. The emaciation and anepithymia manifested in the infected swine mainly related with the decrease of the activity of the digestive enzymes in the intestine, particularly with the significant decrease of the activity of alkaline phosphatase, it inhibits the intestine's digestion of the nutrients, mainly protein, at the same time the decrease of the activity of the alkaline phosphatase also inhibits the absorption of the nutrients.