PAI-1 plays an important role in liver failure after excessive hepatectomy in the rat.

BACKGROUND/AIMS: Well-organized turnover of the extracellular matrix is important in liver regeneration, which is regulated by the plasminogen activating system. The aim of this study was to investigate the role of plasminogen activator inhibitor-1 (PAI-1) after excessive hepatectomy and to ascertain whether angiotensin-converting enzyme (ACE) inhibitors, which are PAI-1 inhibitors as well, successfully improve the survival rate of rats that have undergone 95% partial hepatectomy (PHx).

METHODS

Using liver tissues sampled after 90% or 95% PHx, the expression of PAI-1 mRNA was evaluated using reverse transcription polymerase chain reaction. Hepatic PAI-1 protein and urokinase-type plasminogen activator (uPA) levels were determined by enzyme-linked immunosorbent assay. Survival study and cytodynamic analysis by 5-bromo-2'-deoxyuridine staining were performed to evaluate the effects of ACE inhibition.

RESULTS

The levels of PAI-1 mRNA and hepatic PAI-1 protein in the 95% PHx group peaked and were then maintained. By contrast, the uPA level fell relative to the 90% PHx group. Additionally, the hepatic PAI-1 protein level decreased and the survival rate improved in the 95% PHx rats that had undergone ACE inhibition.

CONCLUSIONS

Our experimental results suggest that PAI-1 plays a role in the occurrence of liver failure after excessive hepatectomy via accelerated maturation of pro-uPA and fibrinolytic factors. These are potential molecular therapeutic targets for liver failure after excessive hepatectomy.