Metabolism of confluent vascular endothelial cell cultures

Confluent endothelial monolayers were kept for a period of about 75 h without medium change. The concentrations of D-glucose, L-lactate, ammonium ions and amino acids in the conditioned media were determined at various time points. From the concentration versus time curves rates were calculated for the various metabolites. The vitality of confluent endothelial monolayers remained constant during the test period. The only metabolite depleted by human umbilical cord vein endothelial cells (HUVEC) was L-serine, but no loss of vitality of the culture was observed. Potential toxic metabolites such as L-lactate and ammonium ions did not accumulate to critical levels