Effects of dehydroepiandrosterone (DHEA) and lactate on glucose uptake in the central nervous system.

Dehydroepiandrosterone (DHEA) prevents brain aging, enhances the cerebral metabolism and interacts with energy substrates. The interaction between lactate and DHEA on glucose uptake and lactate oxidation by various nervous structures was investigated and results demonstrate that the 2-(14)C-deoxiglucose (2-(14)C-Dglucose) uptake was stimulated by 10mM lactate in the hypothalamus and olfactory bulb, inhibited in the cerebral cortex and cerebellum, and unaffected in the hippocampus. We also show that, in both the cerebral cortex and hypothalamus, (14)C-lactate oxidation was higher than (14)C-glucose oxidation (p≤0.001), demonstrating a relevant role for lactate as energy substrate. The interaction of lactate and 10(-8)M DHEA was tested and, although DHEA had no significant effect on uptake in the cerebellum, hippocampus, or hypothalamus, 10(-8)M DHEA increased the 2-(14)C-Dglucose uptake in the cerebral cortex in the presence of lactate (p≤0.001), and in the olfactory bulb in the absence of lactate (p<0.05). However, DHEA had no significant effect on (14)C-lactate oxidation. We suggest that DHEA improves glucose uptake in specific conditions. Thus, DHEA may affect CNS metabolism and interact with lactate, which is the most important neuronal energy substrate, on glucose uptake.