The Mechanisms Of Selenium Deficiency Induce Jejunum Tunica Mucosa Epithelial Cell Apoptosis In Chicks

In order to research the effect of Selenium deficiency in chick jejunum mucosal epithelial cell apoptosis, This experiment we select 120 1st instar SPF chicks which were randomly divided into the experimental group and control group(n=60), Selenium deficiency model of chickens through artificial reproduction, and respectively 7, 21 and 35 days of age and profile to kill sampling. HE staining methods for detection of jejunal mucosa morphology and intestinal epithelial cells and changes in the number of intraepithelial lymphocytes; ultraviolet Colorimetric detection of jejunum mucosa Glutathione peroxidase(GSH-PX) activity, through ABST method to detect total antioxidant capacity, by NBT chromogenic reaction for detection of SOD activity by colorimetric assay for tissue MDA content; Application of DNA ladder and TUNEL detection methods on apoptosis in jejunal mucosal epithelial cells were detected using Western blot and Immunohistochemistry methods in the jejunal Mucosa, BCL-2, caspase-3, and Cleaved Caspase-3 detect changes in protein expression levels. To reveal the relationship between selenium and apoptosis of epithelial cells,the main results are as follows:(1) Treatment group compared with the control group, height of villus, depth of villus and muscle layer thickness, intestinal mucosal epithelial cells and intraepithelial lymphocyte counts were decreased, on the 21 st day of age and 35 days of age were significantly decreased(p<0.01).(2) Treatment group compared with the control group, 7th-day-old GSH-PX activity,tissue total antioxidant ability and SOD activity was significantly decreased(p<0.05), no significant differences in MDA content(p>0.05). On the 21 st day of age and at the age of 35 days, GSH-PX, tissue total antioxidant ability and SOD activity decreased significantly(p<0.01),MDA content increased significantly(p<0.01).(3) Treatment group compared with the control group, DNA ladder at 35 days of age detected in chick jejunum mucosa resulting in degradation of DNA fragments, 7, 21 and 35 days old chicks increased number of jejunal mucosal epithelial cell apoptosis(p<0.0.1).(4) Treatment group compared with the control group was that 7th in intestinal mucosa of ageing moment and space BCL-2 and no significant differences in the expression of Caspase-3 protein(p>0.05), 21 st age reduce the level of expression of BCL-2(p<0.01), reduce the level of expression of Caspase-3(p<0.05), average 35 days of age BCL-2and Caspase-3 water(p<0.01), Cleaved Age of Caspase-3 in the 21 st and was expressed at theage of 35 days.To sum up, selenium deficiency affecting the development of jejunal mucosa morphology of chickens, causing epithelial cells and a decrease in the number of intraepithelial lymphocytes,jejunal mucosa antioxidant capacity, reduce the level of expression of BCL-2 and Caspase-3 in chick jejunum Mucosa, Cleaved elevated levels of Caspase-3 expression, leading to increased number of jejunal mucosal epithelial cell apoptosis in chicks.