Glutamine uptake and expression of mRNA’s of glutamine transporting proteins in mouse cerebellar and cerebral cortical astrocytes and neurons

摘要: Abstract The relative roles of the three sodium-dependent transport systems: A, ASC and N in uptake [ 3 H ]Gln, compatibility characteristics with expression mRNAs coding for Gln transporting molecules, were examined primary cultures astrocytes neurons derived from mouse cerebellum, a glutaminergic system-enriched structure, cerebral cortex. activity (Vmax) was higher cerebellar or than their cortical counterparts. N-methylamino-isobutyric acid (MeAiB)- pH-sensitive, system A-mediated component uptake, 14 C ]MeAiB itself, much more active either region. Also, mRNA GlnT (SAT1), A isoform specific Gln, only expressed both structures, while an alanine (Ala)-preferring transporter, SAT2, System ASC-mediated ASCT2 structures pronounced neurons, consistent postulated role efflux de novo synthesized astrocytes. N-mediated (threonine+MeAiB-inhibitable) showed comparable activities all four types cells, which is compatible ubiquitous NAT2 mRNA—a brain-specific N-system isoform.