Figure 6.

Glycolysis and TCA cycle metabolism are augmented in cultured astrocytes exposed to norepinephrine. Cultured astrocytes were superfused for 60 min with medium containing 2.5 mM of [1,6-¹³C]glucose in the absence (control; white bars) or presence of 100 μ M norepinephrine (NE; black bars). The percent ¹³C enrichment in lactate, reflecting glycolytic activity (A) and glutamate, reflecting TCA cycle metabolism of acetyl-coA derived from glucose (B) was monitored employing liquid chromatography—mass spectrometric (LC-MS) analyses. Statistically significant differences between controls and NE treated astrocytes were determined using an unpaired Student's T-test (P < 0.05) and are indicated by an asterisk (^*). Data modified from Walls et al. (2009).