ABSTRACT
AIM: To study the difference in glucose and lactate levels between brain extracellular fluid (ECF) and plasma in rabbits in the different blood glucose levels. METHODS: Using intracerebral microdialysis technology, brain ECF levels of glucose and lactate were measured in every 10 min under basal conditions and during a hyperglycemia-hypoglycemia clamp study. RESULTS: Under basal condition, brain ECF glucose levels were markedly lower than ambient plasma levels (30% of plasma), whereas ECF lactate levels were substantially higher (165% of plasma). During the hyperglycemia-hypoglycemia clamps, the relationship between plasma and ECF levels of glucose remained similar, but changes in ECF glucose lagged about 30 min. There were no substantially changes in ECF levels of lactate during dynamical study. CONCLUSION: There are striking differences in glucose and lactate levels between brain ECF and plasma. Lactate may involve in the metabolic process of central nervous system.