Leucocyte and platelet adhesion in different layers of the small bowel during experimental total warm ischaemia and reperfusion.
BACKGROUND
Ischaemia and reperfusion (IR) of the small bowel is involved in many clinical conditions. A key component in IR-induced tissue damage is microvascular dysfunction. The aim was to investigate the role of leucocytes and platelets in capillary flow impediment and tissue damage.


METHODS
Anaesthetized rats were subjected to 30 min warm ischaemia of the small bowel, followed by 1 h reperfusion. To elucidate the influence of leucocytes on platelet adhesion, leucocyte-vessel wall interactions induced by IR were prevented by anti-platelet activating factor (PAF) or anti-intercellular adhesion molecule (ICAM)-1. Intravital videomicroscopy was performed and tissue injury was evaluated histologically.


RESULTS
In submucosal venules, IR induced an increase in the median number of interacting leucocytes from 3 to 10 and 20 leucocytes per 100-microm venule segment after 10 and 60 min reperfusion respectively. Anti-PAF or anti-ICAM-1 completely attenuated this increase, resulting in an eightfold improvement in submucosal capillary flow and reduced tissue injury. Shedding of villi no longer occurred. Platelet-vessel wall interactions occurred particularly in submucosal venules, but were not affected by anti-PAF or anti-ICAM-1.


CONCLUSIONS
Small bowel IR initiated an inflammatory and thrombotic response in the submucosal layer only. Attenuation of leucocyte adhesion improved submucosal capillary perfusion, preventing shedding of mucosal villi.
Beuk
R J
RJ
Department of Surgery, Medisch Spectrum Twente, Enschede, The Netherlands. r.beuk@ziekenhuis-mst.nl
Tangelder
G-J
GJ
Maassen
R L J G
RL
Quaedackers
J S L T
JS
Heineman
E
E
Oude Egbrink
M G A
MG
D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D001783:Blood Flow Velocity / Q000502:physiology; D002196:Capillaries / Q000502:physiology; D002448:Cell Adhesion / Q000502:physiology; D018799:Intercellular Adhesion Molecule-1 / Q000276:immunology / Q000502:physiology*; D007421:Intestine, Small / Q000098:blood supply*; D007962:Leukocytes / Q000502:physiology*; D008833:Microcirculation / Q000502:physiology; D010972:Platelet Activating Factor / Q000037:antagonists & inhibitors / Q000502:physiology*; D010973:Platelet Adhesiveness / Q000502:physiology*; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology; D011726:Pyridinium Compounds / Q000494:pharmacology; D011897:Random Allocation; D051381:Rats; D011917:Rats, Inbred Lew; D015424:Reperfusion / Q000379:methods; D015427:Reperfusion Injury / Q000276:immunology; D044005:Tetrahydroisoquinolines / Q000494:pharmacology; D052096:Warm Ischemia / Q000379:methods
D000911:Antibodies, Monoclonal; D010972:Platelet Activating Factor; D010975:Platelet Aggregation Inhibitors; D011726:Pyridinium Compounds; D044005:Tetrahydroisoquinolines; D018799:Intercellular Adhesion Molecule-1; C067430:TCV 309