Mitochondrial function in hepatocyte monolayer cultures

Proceedings of the British Toxicology Society Annual Congress, Heriot Watt University and Neurotox 2003, University of Nottingham, UK, 1st - 4th September 2003. Paper describing the mitochondrial function in hepatocyte monolayer cultures. Many drug metabolising enzymes important in toxicology, such as cytochrome P-450, display a decrease in activity after time in culture, and after the process of cryopreservation (Lawrence and Benford, 1991). Cytochrome P-450 activity requires the availability of free NADPH in the cytosol, which is generated both in the oxidative stage of the pentose phosphate pathway and in the pyruvate-malate cycle by functional mitochondria (Mandl et al., 1995). Cryopreservation has been reported to perturb mitochondrial function in cryopreserved (Dabos et al., 2002; Lawrence and Benford, 1991) and hypothermically stored (Kerkweg et al., 2003) hepatocytes, but to our knowledge this has not been investigated in rat hepatocytes cryopreserved as monolayers. In the present study, the mitochondrial membrane potential (-Ψmit) of primary rat hepatocytes cultured and cryopreserved as monolayers of cells on collagen coated culture dishes was assessed by the fluorescent -Ψmit indicator tetramethylrhodamine ethyl ester (TMRE).