The Studies Of Jejunum And Immc Damage Induced By Selenium Deficiency In Chicken

As a kind of essential nutritive material for human beings and animals, Selenium has the important function of protecting cell membrane structure, enhancing the immunity function of organism, as well as preventing disease. However, as a consequence of many factors, including low selenium content in soil or low exploitability of selenium, intestinal passive absorption, troubled process of composing Selenomethionine in liver, the disease of selenium deficiency in livestock and poultry still occurs from time to time, resulting in huge loss. Currently, the research on Selenium deficiency is mainly focused on anti-oxidation, apoptosis and so on. As an important effector cell in mucosal immune system, mast cells exist in a wide range in tissues and organs of the body, regulating the function of tissues and organs and adjusting the process of tissue injury. However, there have been no reports on whether selenium deficiency can lead to damage to mast cells and mast cells'function in intestinal injury caused by selenium deficiency so far.For this reason, this experiment chose one-day-old Isa roosters as trial subjects, and fed them with feeding stuffs lack of selenium (selenium content: 0.032mg/kg), with the purpose of making case model of selenium deficiency. And then the experimenter got sample by beheading them in batches respectively at 30th day, 45th day, 60th day and 75th day. Through observing drum dyeing and ultrastructure in jejunum, detecting the Se content in blood serum and jejunum, the histamine content and 5-HT content in blood serum, as well as detecting the expression of H2R and VIPR-1 mRNA, the experimenter made a study of selenium deficiency's influence on the structure and function of mast cells in jejunum, and on pathomechanism of intestinal tissue injury caused by mast cells. The findings show:â… Through the observation of clinical symptoms, pathological autopsy and histology, changes in histology and determination of selenium content, the experiment successfully made the case model of se-deficiency .â…¡With the extension of trial period, selenium deficiency resulted in the fact that histamine content in blood serum and H2R mRNA expression in jejunum was significantly higher than control group (P <0.01), which shows time effect. This indicates that selenium deficiency can lead to mast cells'oxidative stress and make degranulation release bioactive substances.â…¢With the extension of trial period, selenium deficiency resulted in the fact that 5-HT cont -ent in blood serum and VIPR-1 mRNA expression in jejunum was obviously higher than control group (P <0.01), which shows time effect. This indicates that selenium deficiency can lead to inju -ry of nerve by suppressing the secretion of neurotransmitter, lowering its content. 5-HT,VIP are part of inhibitory neurotransmitter, which can inhibit the injury of mast cells. So, this probably is one of the protection mechanisms of mast cells injuries caused by selenium deficiency.â…£Prompts the immune system caused by intestinal injury, intestinal mucosal mast cells (IMMC) increase in the number of local defense of the body are an important response to the performance.Through observing the micro-structure and ultrastructure of jejunum, the experimenter confirmed that selenium deficiency can cause the injury of smooth muscle cell in jejunum, intestinal mucosal thickening and congesting; the number of MC in jejunum was obviously increased and had different subtypes; with the extension of the trial period, there appeared vacuoles in degranulation. This result shows that the injury of intestinal mucosa's immune system and the increase of mast cells (IMMC) in intestinal mucosa that caused by selenium deficiency is an important manifestation of body's defensive reaction.In a word, selenium deficiency can make the number of IMMC, which are regulated by the network of nerve, endocrine and immune system, increase and occur oxidative stress; can make the degranulation release substantial medium, so that the histamine content in blood serum and the expression of histamine receptors in jejunum would increase; and can recruitment inflammatory cells, causing pathological damage to intestinal tissue. Besides, selenium deficiency can cause nerve injury, and so can made enteric nerve change the signal transmitted through it which will lead to inhibited secretion of 5-HT, the reduction of VIP receptor's expression, showing that selenium deficiency can affect the structure and function of mast cell, and probably can promote the development of intestinal injury through the medium of mast cells. However, selenium deficiency's molecule mechanism on mast cells'release of medium still needs further research.