Intraportal perfusion of prostaglandin E1 attenuates hepatic postischaemic microcirculatory impairments in rats

Background: The efficacy of intraportal perfusion with prostaglandin E(1) (PGE(1)) in decreasing postischaemic hepatic microcirculatory damage was studied in rats. Methods: An extrahepatic portosystemic shunt was created by attaching the spleen to a subcutaneous site on the left lateral wall of the abdomen in male Wistar rats weighing between 200 and 350 g. Four weeks later, when the shunt was mature, the portal vein and hepatic artery were occluded for 60 min. The animals were divided into the following three groups according to the type of intraportal perfusion during the ischaemic phase: group 1 consisted of untreated animals; group 2, animals perfused with lactated Ringer's solution; and group 3, animals perfused with PGE(1) (0.1 mu g/kg per min). The hepatic microcirculation was observed under an inverted intravital microscope after the injection of fluorescent dyes to label leucocytes and damaged cells 30 and 60 min after reperfusion. The liver was removed 60 min after reperfusion and stained immunohistochemically using 1A29, an anti-rat intercellular adhesion molecule-1 (ICAM-1) antibody. Results: The leucocyte velocity during reperfusion was lowest in group 1 and highest in group 3. Of the three groups, group 3 showed the least leucocyte adhesion to the sinusoidal walls and terminal venules, the lowest damaged cell count and the lowest ICAM-1 expression on the sinusoidal walls. Conclusion: The results of this study suggest that hepatic perfusion with PGE, markedly alleviates microcirculatory damage associated with ischaemia and reperfusion through the inhibition of leucocyte-endothelium interactions. (C) 1999 Blackwell Science Asia Pty Ltd.