Cerebral ketone body oxidation is facilitated by a high fat diet enriched with advanced glycation end products in normal and diabetic rats

Diabetesmellitus(DM)causesimportantmodificationsintheavailabilityanduseofdifferentenergysubstratesinvariousorgansandtissues.Similarly,dietarymanipulationssuchashighfatdietsalsoaffectsystemicenergymetabolism.However,howthebrainadaptstothesesituationsremainsunclear.Toinvestigatetheseissues,controlandalloxan-inducedtypeIdiabeticratswerefedeitherastandardorahighfatdietenrichedwithadvancedglycationendproducts(AGEs)(HAGEdiet).TheHAGEdietincreasedtheirlevelsofbloodketonebodies,andthiseffectwasexacerbatedbyDMinduction.Todeterminetheeffectsofdietand/orDMinductiononkeycerebralbioenergeticparameters,bothketonebodies(b-hydroxybutyricacid)andlactateoxidationweremeasured.Inparallel,theexpressionofMonocarboxylateTransporter1(MCT1)and2(MCT2)isoformsinhippocampalandcorticalslicesfromratssubmittedtothesedietswasassessed.KetonebodyoxidationincreasedwhilelactateoxidationdecreasedinhippocampalandcorticalslicesinbothcontrolanddiabeticratsfedaHAGEdiet.Inparallel,theexpressionofbothMCT1andMCT2increasedonlyinthecerebralcortexindiabeticratsfedaHAGEdiet.TheseresultssuggestashiftinthepreferentialcerebralenergysubstrateutilizationinfavorofketonebodiesinanimalsfedaHAGEdiet,aneffectthat,inDManimals,isaccompaniedbytheenhancedexpressionoftherelatedtransporters.