EFFECT OF 1,3-BUTANEDIOL ON CEREBRAL ENERGY-METABOLISM - COMPARISON WITH BETA-HYDROXYBUTYRATE

Previous studies have shown that 1,3-butanediol (BD) has beneficial ef fects in experimental models of hypoxia or ischemia but the mechanism by which it exerts its protective effects remains unknown. BD is conve rted in the body to B-hydroxybutyrate (BHB) and it has been proposed t hat its effects were linked to its ketogenic effect. The effects of BD (25 and 50 mmol/kg) on cerebral energy metabolism of rats were studie d by measuring the cerebral level of energy metabolites and by evaluat ing the cerebral metabolic rate according to the Lowry's method. BD in duced an increase in [cortical glucose]/[plasma glucose] ratio which w as associated with a decrease in lactate level and an increase in gluc ose and glycogen stores. In contrast, BHB treatment which mimicked hyp erketonemia equivalent to BD did not modify cerebral glycolysis metabo lites. Calculation of the energy reserve flux after decapitation showe d that BD did not reduce the cerebral metabolic rate excluding a prote ctive effect due to a depressant, barbiturate-like, action. These resu lts suggest that BD induces a reduction of cerebral glycolytic rate. H owever, the effect is not linked to hyperketonemia but might be due to intracerebral conversion of BD to BHB.