Changes in glucose oxidation during growth of embryonic heart cells in culture.

A rapid and convenient method has been utilized to investigate glucose oxidation during growth of chick embryo heart cells in tissue culture. Primary isolates of chick embryo heart cells showed exponential growth when plated at low densities and exhibited density-inhibited growth as cultures became confluent. The density-dependent growth inhibition of chick embryo heart cells is associated with a marked decrease in the specific activity of glucose oxidation to CO(2). This decrease in glucose oxidation was observed as density increased as either a function of time in culture or as related to initial plating density. The decrease in (14)CO(2) production associated with density-dependent inhibition of growth is due to a marked decrease in activity of the pentose phosphate pathway.