Techniques for measurement of oxygen consumption rates of hepatocytes during attachment and post-attachment.

Three techniques for measuring oxygen consumption rate (OCR) of cultured cells relevant to the development of bioartificial liver devices are reported. In an oxystat apparatus, HepG2 cells immobilised on Cytodex 3 microcarriers at a concentration of 10(6) cells ml-1 had a mean OCR of 0.7 nmol s-1/10(6) cells. The OCR decreased with increasing cell density, a characteristic previously reported for other cell lines. Rat hepatocytes immobilised on single collagen layers in a flow cell and challenged with ammonia had a mean OCR of 0.59 nmol s-1/10(6) cells. A novel two-compartment oxystat system was used to determine the OCR of rat hepatocytes during the attachment phase. OCR declined from 1.0 nmol s-1/10(6) immediately after seeding to 0.7 nmol s-1/10(6) cells at nine hours. The low OCR for HepG2 reflects loss of certain oxygen dependent metabolic pathways. The OCR measured for rat hepatocytes during and post-attachment are significantly higher than those reported elsewhere and have major implications for the development of bioartificial liver devices.