A computational model for hepatotoxicity by coupling drug transport and acetaminophen metabolism equations.

The spatial distributions of cytochrome P450 (CYP450) and glutathione (GSH) in liver lobules determine the heterogeneous hepatotoxicity of acetaminophen (APAP). Their interplay in conjunction with blood flow is not well understood. In this paper, we integrate a cellular APAP metabolism model with a sinusoidal blood flow to simulate the temporal-spatial patterns of APAP-induced hepatotoxicity. The heterogeneous distribution of CYP450 and GSH is modeled by linearly varying their reaction rates along the portal triad to the central vein axis of a sinusoid. We found that the spatial distribution of GSH, glutathione S-transferases (GSTs), and CYP450 all contributes to the high acetaminophen protein adduct formation at zone 3 of the lobules. The reversed spatial gradients of CYP450 and GSH cause quick depletion of GSH, which is further accelerated by the distribution of GST. The hepatic flow congestion and hyperperfusion however do not seem to play a significant role in the zonal hepatotoxicity. The simulation results may be useful for understanding the APAP-induced hepatotoxicity and associated pharmaceutical treatment.