leucocyte-endothelial cell adhesion in intestinal inflammation

Background-An important action of interleukin 8 (IL8) is stimulation ofgranulocytes. The object of this study was to assess the contribution ofIL8 to the leucocyte-endothelial celi interactions associated with intestinal inflammation in the rat. Methods-Two indomethacin injections (48 and 24 hours prior to the experiments) induced a longlasting ileitis in rats. The number of adherent and emigrated leucocytes, leucocyte rolling velocity, and shear rate were monitored in normal and inflamed mesenteric postcapillary venules. Some animals received a monoclonal antibody (MAb) against IL8 or CD1lb/CD18 at 24 and 12 hours prior to the experiment. Results-Indomethacin elicited a sevenfold increase in leucocyte adherence and a 54-fold increase in leucocyte emigration, while leucocyte rolling velocity was reduced by nearly 80%. The indomethacin induced increases in leucocyte adherence and emigration were significantly reduced (by 57% and 67%, respectively) while leucocyte rolling velocity was increased (to 63% of control) by the IL8-specific MAb. The level ofinhibition seen with the IL8 MAb was similar to that associated with administration of a MAb directed against the leucocyte adhesion molecule CD1lb/CD18. Conclusions-IL8 contributes to the leucocyte-endothelial cell interactions elicited in mesenteric venules by indomethacin. (Gut 1996; 38: 911-915) Department of Physiology and Biophysics, Louisiana State University Medical Center, USA D N Granger Department of Internal Medicine I, University of Regensburg, Germany H Arndt Molecular and Celiular Biology, The Monsanto Company, St Louis, Missouri, USA A Bolanowski Correspondence to: D N Granger, PhD, Department of Physiology and Biophysics, Louisiana State University Medical Center, 1501 Kings Highway, Shreveport, Louisiana 71130-3932, USA. Accepted for publication 29 December 1995