LACTATE TRANSPORT IN CULTURED GLIAL-CELLS

Uptake of L-lactate was investigated with a radioactive tracer method in cultured rat glioma cells and in astroglia-rich primary cultures de rived from rat brain. In the glioma cells, a saturable component of up take was identified with half-maximal uptake occurring at 1.0 +/- 0.4 mM lactate. In addition, a non-saturable component dominated the uptak e at high concentrations of lactate. In astroglia-rich primary culture s, no saturable component of uptake could be detected in the concentra tion range studied (0.1 - 15 mM). In conclusion, lactate uptake at phy siological concentrations is predominantly mediated in the glioma cell s by a carrier-dependent process, whereas in astroglial cells, simple diffusion appears to be the dominant way of lactate transport.