title: [Changes in endothelial progenitor cells and their implications in multiple organ dysfunction syndrome caused by trauma in pigs].
abstract: OBJECTIVE
  To investigate characteristics of changes in bone marrow endothelial progenitor cells (EPCs) and implications on multiple organ dysfunction syndrome (MODS) as a result of trauma.
  
  
  METHODS
  Eighteen mini-pigs were randomized into two groups: MODS group (n=9) and control group (n=9). The animal models of MODS were reproduced by "two-hit" injury with hemorrhagic shock and lipopolysaccharide (LPS) injection. Bone marrow and peripheral blood of them were collected at five time points: normal condition (T1), before injection of LPS (T2), and 0 (T3), 24 (T4) and 48 hours (T5) after injection of LPS. Erythrocytic lysate was added to the samples, and the number of leucocytes in every sample was counted. The rate of EPCs in each sample was determined by flow cytometry. Number of EPCs in bone marrow and peripheral blood were calculated, and the results were analyzed statistically.
  
  
  RESULTS
  The number of EPCs (x10(6)/L) in bone marrow of control group at T1-5 was 7.64+/-0.68, 7.32+/-0.55, 7.58+/-1.13, 7.77+/-0.70, and 7.88+/-0.84, respectively, and in peripheral blood control group was 3.54+/-0.26, 4.06+/-0.64, 3.74+/-0.55, 3.61+/-0.37, and 3.98+/-0.63, respectively. The number of EPCs (x10(6)/L) in bone marrow in the experimental group was 7.45+/-1.55, 6.58+/-0.80, 11.27+/-1.20, 10.88+/-1.15, and 8.36+/-2.88, respectively. The number of EPCs (x10(6)/L) in peripheral blood in the experimental group was 3.21+/-0.48, 8.71+/-2.04, 5.98+/-0.77, 1.27+/-0.91, and 2.14+/-0.96, respectively. The number of EPCs in bone marrow of experimental group was larger than that of control group at T3, T4, T5. The number of EPCs in the experimental group in peripheral blood was larger than that of control group at T2, T3, T4, T5. The number of EPCs in bone marrow was larger than that in peripheral blood at every time point (all P<0.05).
  
  
  CONCLUSIONS
  The number of EPCs in peripheral blood elevates sharply in the earlier period, then plummeted quickly during MODS after a trauma. While the number of EPCs in bone marrow descends mildly at first, then rises obviously. Along with the aggravation of MODS, a declination of EPCs in bone marrow emerges. The change in bone marrow EPCs plays an important role in recovery of MODS.
authors.affiliation: Department of General Surgery, Changhai Hospital Affiliated to Second Military Medical University, Shanghai 200433, China.
authors.forename: Wen-zheng
authors.initials: WZ
authors.lastname: Fu
authors.forename: An-rong
authors.initials: AR
authors.lastname: Mao
authors.forename: Tian-hang
authors.initials: TH
authors.lastname: Luo
authors.forename: Guo-en
authors.initials: GE
authors.lastname: Fang
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D004195:Disease Models, Animal; D042783:Endothelial Cells / Q000473:pathology*; D008297:Male; D009102:Multiple Organ Failure / Q000209:etiology / Q000473:pathology*; D012771:Shock, Hemorrhagic / Q000150:complications; D013234:Stem Cells / Q000473:pathology*; D034421:Sus scrofa; D013552:Swine