On leukocyte stasis in hepatic sinusoids. Vollmar, Brigitte, Sven Richter, Michael D. Menger. Institute for Clinical & Experimental Surgery, University of Saarland, D-66421 Homburg/Saar, Germany
APStracts 2:0255G, 1995.
There is ongoing debate on the significance of capillary leukostasis for the manifestation of ischemia-reperfusion (I/R)-induced capillary "no-reflow". Using intravital fluorescence microscopy, we studied leukocyte trafficking through the hepatic microvasculature and the relevance of sinusoidal leukostasis for nutritive perfusion failure in rats following hepatic I/R (n=8). Sham-operated animals (n=8) served as controls. Hepatic reperfusion was characterized by perfusion failure of individual sinusoids and a significant increase of sinusoidal leukostasis. However, in both non-ischemic and postischemic livers, the major fraction of sinusoids presenting with stagnant leukocytes were found perfused (97+/-1% and 73+/-5%, respectively), while only 3+/-1% and 27+/-5% failed to conduct flow. Analysis of leukocyte trafficking in sinusoids with leukostasis revealed a marked reduction of leukocyte velocity and leukocyte flux in non-ischemic and postischemic livers when compared to sinusoids without leukostasis. Thus, stagnant leukocytes retard cellular passage through hepatic sinusoids, probably due to an increase of flow resistance. However, the fact that during postischemic reperfusion more than 70% of the sinusoids accomodating stagnant leukocytes are still perfused, indicate that sinusoidal leukostasis per se does not necessarily determine perfusion failure ("no -reflow") following I/R of the liver.

Received 14 August 1995; accepted in final form 29 November 1995.
APS Manuscript Number G352-5.
Article publication pending Am. J. Physiol. (Gastrointest. Liver
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 23 December 95