Direct Evidence for Intracellular Homeostasis in Mammalian Cells: Insulin-independent Glucose Metabolisms

In our previous study, carbonates, NaHCO3 and Na2CO3, influence glucose metabolism in vitro, using Py-3Y1-S2 rat fibroblast cells, and these compounds accelerate significantly glucose consumption. In the present study, the effects of the carbonates on glucose metabolism were examined to determine whether these effects are universal among different cell lines, VERO green monkey kidney cells, TE-13 human esophageal cancer cells, and HepG2 human cells. Glucose was completely converted to lactate, which disappeared gradually from the culture medium. However, the disappearance of lactate from the medium was independent of carbonates. The present study clarified that NaHCO3 and Na2CO3 directly regulate glucose metabolism among different cell lines via an insulin-independent pathway, that is, intracellular homeostasis.