title: Role of PI3K/Akt signaling in the protective effect of magnesium sulfate against ischemia-perfusion injury of small intestine in rats.
abstract: BACKGROUND
  The protective effects of magnesium sulfate against ischemia-reperfusion injury of the small intestine in Sprague-Dawley (SD) rats have been confirmed in our previous research. However, its exact mechanism is unclear. This study was to evaluate the role of PI3K/Akt signal pathway in the protective effect of magnesium sulfate against ischemia-reperfusion injury of the small intestine in SD rats.
  
  
  METHODS
  Rat model of intestinal ischemia-reperfusion injury was used. The SD rats were divided into four groups randomly: sham operation group, ischemia-reperfusion group, magnesium sulfate group and magnesium sulfate plus LY294002 (an inhibitor of PI3K) group. The pathological changes of intestinal mucosa were examined; the activity of diamine oxidase (DAO) in plasma, the plasma contents of malondialdehyde (MDA), and apoptosis rate of the intestinal mucosal cells were determined and compared. The expression of p-Akt was detected by Western blotting.
  
  
  RESULTS
  There were more evident pathological changes of the intestinal mucosa (higher Chiu's score, P < 0.05), enhanced DAO activity (P < 0.05), elevated contents of MDA (P < 0.05), higher apoptosis rate (P < 0.05), and lower level of p-Akt (P < 0.05) in the ischemia-reperfusion group compared with the sham operation group. There were less evident pathological changes of the intestinal mucosa (lower Chiu's score, P < 0.05), lower DAO activity (P < 0.05), lower contents of MDA (P < 0.05), and lower apoptosis rate (P < 0.05), but higher level of p-Akt (P < 0.05) in the magnesium sulfate group compared with the ischemia-reperfusion group. There were more evident pathological changes of the intestinal mucosa (higher Chiu's score, P < 0.05), higher contents of MDA (P < 0.05), higher DAO activity (P < 0.05) and higher apoptosis rate (P < 0.05), and lower level of p-Akt (P < 0.05) in the magnesium sulfate plus LY294002 group compared with the magnesium sulfate group.
  
  
  CONCLUSIONS
  Activation of PI3K/Akt signal pathway results in the reduction of cell apoptosis, which likely accounts for the protective effect of magnesium sulfate against intestinal ischemia-reperfusion injury.
authors.affiliation: Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong 510080, China.
authors.forename: Shi-da
authors.initials: SD
authors.lastname: Chen
authors.forename: Ya-bin
authors.initials: YB
authors.lastname: Chen
authors.forename: You
authors.initials: Y
authors.lastname: Peng
authors.forename: Jia
authors.initials: J
authors.lastname: Xu
authors.forename: Su-shan
authors.initials: SS
authors.lastname: Chen
authors.forename: Jun-long
authors.initials: JL
authors.lastname: Zhang
authors.forename: Zheng-zhang
authors.initials: ZZ
authors.lastname: Li
authors.forename: Zhi
authors.initials: Z
authors.lastname: Tan
mesh_terms: D006631:Amine Oxidase (Copper-Containing) / Q000378:metabolism; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D004195:Disease Models, Animal; D007413:Intestinal Mucosa / Q000166:cytology / Q000187:drug effects; D007421:Intestine, Small / Q000187:drug effects*; D008278:Magnesium Sulfate / Q000627:therapeutic use*; D008315:Malondialdehyde / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000517:prevention & control*; D015398:Signal Transduction / Q000187:drug effects*
chemical_list: D008315:Malondialdehyde; D008278:Magnesium Sulfate; D006631:Amine Oxidase (Copper-Containing); D051057:Proto-Oncogene Proteins c-akt