title: Activation of phosphorylating-p38 mitogen-activated protein kinase and its relationship with localization of intestinal stem cells in rats after ischemia-reperfusion injury.
abstract: OBJECTIVE
  To investigate the expression of phosphorylating p38 mitogen-activated protein kinase (MAPK) in rat small intestine after ischemia-reperfusion (I/R) insult and its relationship with the localization of intestinal stem cells.
  
  
  METHODS
  Forty-eight Wistar rats were divided randomly into three groups, namely intestinal ischemia-reperfusion group (R), intestinal ischemia group (I) and sham-operated control group (C). In group I, the animals were killed 45 minutes after superior mesenteric artery (SMA) occlusion, while in group R the rats sustained SMA occlusion for 45 minutes and reperfusion for 2, 6, 12 or 24 hours respectively. In sham-operated control group, SMA was separated, but without occlusion. The activity of plasma diamine oxidase (DAO) was determined. Intestinal tissue samples were also taken for histological analysis and immunohistochemical analysis of MAPK p38 detection and intestinal stem cell localization.
  
  
  RESULTS
  The changes in histological structure and plasma DAO levels indicated that the intestinal barrier was damaged after intestinal I/R injury. In group C and I, each crypt contained 5-6 p38 MAPK positive cells, which were mainly located in the lower region of the crypts. This was consistent with the distribution of intestinal stem cells. The presence of positive cells in crypts increased with the time of reperfusion and reached its peak at 12 hours after reperfusion (35.6 %).
  
  
  CONCLUSIONS
  After intestinal I/R injury, the expression of phosphorylating-p38 MAPK in small intestine increased with the duration of reperfusion, and its distribution coincided with that of intestinal stem cells and their daughter cells, indicating that phosphorylating-p38 might be a possible marker of intestinal stem cells.
authors.affiliation: Wound Healing and Cell Biology Laboratory, Institute of Burns, 304 Hospital, Trauma Center of Postgraduate Medical College, 51 Fu Cheng Road, Beijing 100037, China. fuxb@cgw.net.cn
authors.forename: Xiao-Bing
authors.initials: XB
authors.lastname: Fu
authors.forename: Feng
authors.initials: F
authors.lastname: Xing
authors.forename: Yin-Hui
authors.initials: YH
authors.lastname: Yang
authors.forename: Tong-Zhu
authors.initials: TZ
authors.lastname: Sun
authors.forename: Bao-Chen
authors.initials: BC
authors.lastname: Guo
mesh_terms: D000818:Animals; D004789:Enzyme Activation; D007421:Intestine, Small / Q000098:blood supply* / Q000201:enzymology* / Q000473:pathology; D008297:Male; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D010766:Phosphorylation; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000201:enzymology* / Q000473:pathology*; D013234:Stem Cells / Q000473:pathology*; D048051:p38 Mitogen-Activated Protein Kinases
chemical_list: D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases