INDUCTION OF CYTOCHROME P-450IA1 ACTIVITY IN RESPONSE TO SUBLETHAL STRESSES IN MICROCARRIER-ATTACHED HEP G2 CELLS

Cell damage for cells grown on microcarriers in suspension is a critic al problem for scale-up of microcarrier reactors. In order to study ce ll damage as a mechanistic process, a cellular response that is more s ensitive than changes in growth and death rates and would be more clos ely related to cell regulatory mechanisms would be advantageous. We ha ve observed the induction of a specific cytochrome P-450 monooxygenase , P-450IA1 (CYP1A1), to be a sensitive method for assessing the respon se of microcarrier-attached Hep G2 cells to stress resulting from hydr odynamic shear and oxygen deprivation. The kinetics of induction and a mount of CYP1A1 formed in response to subtle shear stress, moderate sh ear, and hypoxia are described. Increased stress results in increased CYP1A1 formation.