title: Ischaemic preconditioning improves microvascular perfusion and oxygenation following reperfusion injury of the intestine.
abstract: BACKGROUND
  Ischaemia-reperfusion (IR) injury of the intestine occurs commonly during abdominal surgery. Ischaemic preconditioning (IPC) provides a way of protecting the organ from damage inflicted by IR. This study was designed to evaluate the beneficial effect of IPC, focusing on the intestinal microcirculation and oxygenation in intestinal IR injury.
  
  
  METHODS
  Rats were allocated to three groups. Animals in the IR and IPC groups underwent 30 min of intestinal ischaemia followed by 2 h of reperfusion. In the IPC group this was preceded by 10 min of ischaemia and 10 min of reperfusion. Animals in the third group underwent laparotomy but no vascular occlusion. Intestinal microvascular perfusion, oxygenation and portal venous blood flow (PVF) were monitored continuously. At the end of the reperfusion period, blood samples were obtained for measurement of lactate dehydrogenase (LDH) and biopsies of ileum for histological evaluation.
  
  
  RESULTS
  : IPC improved intestinal microvascular perfusion and tissue oxygenation significantly at the end of the reperfusion period (P < 0.001). PVF improved significantly in the IPC compared with the IR group (P = 0.005). The serum LDH concentration was significantly lower in the IPC than the IR group (mean(s.e.m.) 667.1(86.8) versus 1973.8(306.5) U/l; P < 0.001) Histological examination showed that ileal mucosa was significantly less injured in the IPC group.
  
  
  CONCLUSIONS
  This study demonstrated that IPC improves intestinal microvascular perfusion and oxygenation.
authors.affiliation: Gastrointestinal and Hepatobiliary Research Unit, University Department of Surgery, Royal Free and University College Medical School, University College London, UK.
authors.forename: I H
authors.initials: IH
authors.lastname: Mallick
authors.forename: W
authors.initials: W
authors.lastname: Yang
authors.forename: M C
authors.initials: MC
authors.lastname: Winslet
authors.forename: A M
authors.initials: AM
authors.lastname: Seifalian
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity; D007422:Intestines / Q000098:blood supply*; D019194:Ischemic Preconditioning; D017078:Laser-Doppler Flowmetry; D008297:Male; D008833:Microcirculation / Q000502:physiology*; D010100:Oxygen / Q000032:analysis*; D011168:Portal System / Q000502:physiology; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D015424:Reperfusion / Q000009:adverse effects; D015427:Reperfusion Injury / Q000503:physiopathology / Q000517:prevention & control*
chemical_list: D010100:Oxygen