UPTAKE OF L-LACTATE BY CULTURED RAT-BRAIN NEURONS

The uptake of L-lactate was investigated in neuronal primary cultures derived from embryonic rat brain with a radioactive tracer method. Aft er preincubation of the cells in glucose-free buffer for 30 min, uptak e increased with time for at least IO min. A saturable component of up take was found with half-maximal uptake at 10 mM lactate. This saturab le component was abolished in the presence of 10 mM alpha-cyano-4-hydr oxycinnamic acid. In addition, a non-saturable component dominated the uptake at high concentrations of lactate. Uptake was accelerated with decreasing pH, and was inhibited considerably by pyruvate. It is conc luded that neurons are endowed with a lactate transport system which r esembles in its properties the monocarboxylate carrier of peripheral t issues.