Ischemia/reperfusion in clamped lobes facilitates liver regeneration of non-clamped lobes after selective portal vein ligation.

Background: Hypertrophy of non-clamped liver lobes and the atrophy of clamped lobes have been shown to be interactive. Here, a rat model of selective lobe occlusion was established to study the effect of contralateral ischemia/reperfusion (I/R) on regeneration of non-clamped lobes.

Methods: Left lateral and middle liver lobes were pretreated with I/R. In the experimental (IR + PVL) group, portal veins of the left and middle lobes were ligated. A group given similar portal vein ligation but no I/R (PVL) was the positive control.

Results: Compared with the PVL group, the IR + PVL had higher, but not remarkable, levels of serum transaminases; weights of non-clamped lobes in the IR + PVL group comparatively increased much more notably. At 24-h post-surgery, the IR + PVL group's PCNA mRNA was up-regulated compared with the PVL group. At 72-h post-surgery, PCNA protein was up-regulated significantly, while TGF-β1 was down-regulated in the IR + PVL group notably, compared with the PVL group.

Conclusion: The I/R pretreatment given to the clamped lobes facilitates liver regeneration of non-clamped lobes after selective portal vein ligation, which may result from down-regulated TGF-β1 expression in non-clamped lobes.