β2- and β3-Adrenoceptors activate glucose uptake in chick astrocytes by distinct mechanisms: a mechanism for memory enhancement?

摘要: Isoprenaline, acting at beta-adrenoceptors (ARs), enhances memory formation in single trial discriminated avoidance learning day-old chicks by mechanisms involving alterations glucose and glycogen metabolism. Earlier studies of consolidation indicated that beta3-ARs enhanced increasing uptake, whereas beta2-ARs enhance glycogenolysis. This study examines the ability beta-ARs to increase uptake chick forebrain astrocytes. The beta-AR agonist isoprenaline increased a concentration-dependent manner, as did insulin. Glucose was beta2-AR zinterol beta3-AR CL316243, but not beta1-AR RO363. In astrocytes, reverse transcription-polymerase chain reaction showed beta1-, beta2-, mRNA were present, radioligand-binding presence only beta2- beta3-ARs. or insulin-mediated inhibited phosphatidylinositol-3 kinase protein C inhibitors, suggesting possible interaction between insulin pathways. However two different mechanisms: via Gs-cAMP-protein A-dependent pathway, while interactions with Gi. These results indicate activation causes astrocytes distinct mechanisms, which may be relevant for enhancement.