Comparative analysis of metabolism of medium- and plasma perfused primary pig hepatocytes cultured around a 3-D membrane network

Culture media are frequently used in the evaluation of metabolical functions of hepatocytes in hybrid liver support systems (hLSS). However, media compositions differ substantially from those of plasma. Therefore, our study was designed to investigate whether current in vitro studies with medium are suitable to assess the metabolical competence of hLSS-cultures during clinical application as well as to explore whether the cell nutrition with medium provides a suitable modus operandi for stand by cultivation. Paired bioreactor cultures were perfused with either Williams' Medium E (MPB) or human plasma (PPB). About 6x108 primary pig hepatocytes (>97% viability) were cultured in three laboratory scale bioreactors designed according to Gerlach's bioreactor-concept. Different perfusion protocols were initiated after a standardised period allowing for cell attachment and reorganisation in aggregates. Whereas patterns of enzyme release were similar in both protocols the metabolical behaviour was different between MPB (anabolic state) and PPB (catabolic state). Furthermore, compared to MPB the lidocaine-MEGX-tests for PPB demonstrated lower MEGX-concentrations and a different reaction pattern. We conclude that the nutrition of hepatocytes with medium during the stand by period itself might influence the cell function and subsequently the efficacy of the hLSS-treatment during clinical application.