The Experimental Study Of The Glia's Function On The Visceral Hyperalgesia In Rats With Irritable Bowel Sydrome

Irritable Bowel Syndrome can lead to visceral hyperalgesia, as well as the changes in gastrointestinal motility, visceral hyperalgesia is remarkable features of IBS.But its mechanism is undefined, particularly nervous and molecular mechanism has not clarified. In the past, visceral sensitivity of IBS patients resulted from increased neuronic activity. Recent research found that glial cells (mainly astrocytes and microglia) played a key role in the initiation and maintenance of pain.Then the function and roles of glial cells in visceral sensitivity reaction of IBS are vague.It is essential to resovle this problem for studying the mechanism of IBS and researching a new way for exploring new drugs. Use trichina cystica to infect the rats and induce inflammation in the digestive tract and successfully establish animal models of IBS, Then stimulate IBS rat with dilatation in the colon and observe the behavior of visceral pain in IBS By using the ethology, electrophysiology and immunohistochemistry methods to detect the IBS behavior of visceral pain in IBS of rats and the changes of neurons and glial cells in DCN,which is an initial integration and regulation center of colon, under different dilatation pressure stimulus conditions.According to the above the test , given a block which can interrupt metabolic functiong of glial cell in IBS rat at the peak point of behavior visceral pain in IBS rats , and observe the changes on behavior of visceral pain and the changes of neurons and glial cells in DCN , to argumentate the mechanism of glial cells in IBS.That is important for resolving visceral hyperalgesia and for exploring new drugs for IBS.Methods By using trichina cystica to infect rats and successfully establish animal models of IBS. To utilizate the ethology, electrophysiology and immunohistochemistry methods to explore the mechanism of neuronic molecular biology and pathogenesis in IBS.Results1. The successful logo of IBS rats model:â‘ There are some cysts of trichinella spiralis in the skeletal muscles;â‘¡There are a few of chronic inflammatory corpuscle in the colon of infected rats;â‘¢The changes of ethology and electro activity of external oblique muscle of abdomen in the IBS rats are significantly than those in the normal rats.2. Distented stimulation of the colon induced the visceral pain,and which not only activated the neurons, but also activated glial cells (astrocytes and microglia) of DCN in the spinal cord.In preliminary study,we find that the activation of astrocytes is early than microglia cells.3. Under the same conditions, By using a block(propentofylline) to intervene,the propentofylline(PPF) can interrupt metabolic function of glial cell.The glial cells activation level decrease significantly and neuronic activation level are similar to the glial cells. In the mean time, the behavior of visceral pain also decreasedobviously in IBS rats.Conclusionâ‘ Rats infected with trichinella spiralis can induce visceral sensitization which was in line with the phenomenon of visceral sensitivity in IBS patients;â‘¡Distention stimulus in the colon can result in visceral pain,which activated neurons and glial cells, and glial cells play a role in this reaction.â‘¢Astrocytes probably are the "kick-off" factor in the visceral hyperalgesia, and glial cells probably play an important role in its maintaining function.