Previously published work on the effect of agitation on cultured animal cells has concentrated either on the macroscopic effects on percent viable, growth rate, or antibody productivity, or on the aspects of turbulence that correlate with these cellular responses. In this proposal the focus is on the cell itself, and in particular the balance it maintains between internal and external concentrations of calcium, sodium, potassium, and hydrogen. The steady state and dynamic responses of intracellular ion concentrations to various levels of agitation will be measured using a custom built high speed ratioing fluorometer. Energy related variables such as ATP and NADH levels, specific consumption rates of glucose, glutamine, and oxygen, and production rate of lactate will be determined also. GAP-A3 hybridomas, CHO, and BHK-21 cells will be used. The independent variables to be evaluated include agitation speed, impeller design, physical properties of the medium, dissolved oxygen concentration, and external concentrations of the ions of interest. This work will investigate some of the basic cellular responses to agitation, yet also consider practical modifications to culture conditions to control those responses.
