Fig. 2

Relationships between glucose metabolism and cytosolic NADH:NAD⁺ ratio. a Factors that reduce glucose flux through glycolysis, such as reduced glucose availability or glycolytic inhibitors, reduce NADH levels and thereby reduce NADH:NAD⁺ ratio, whereas factors that inhibit oxidative metabolism, such as hypoxia and mitochondrial inhibitors, have the opposite effect. Glutamine provides ketone bodies (α-ketoglutarate) to fuel mitochondrial ATP production in the absence of glycolysis. Lactate dehydrogenase (LDH) maintains the lactate:pyruvate ratio in equilibrium with the cytosolic NADH:NAD⁺ ratio. b The lactate:pyruvate ratio provides an index of the cytosolic NADH:NAD⁺ ratio in cells treated with glycolytic and mitochondrial inhibitors. 2DG, 1 mM 2-deoxyglucose; 0 Glu, glucose-free medium; CoCl₂, 200 µm cobalt chloride; antimycin, 1 µm antimycin A. n = 4; *p < 0.05 v. control. c LPS-induced iNOS expression was suppressed in RAW267.4 cells treated with 1 mM 2DG or glucose-free medium, and increased in cells treated with the mitochondrial inhibitor cobalt chloride (CoCl_2, 200 µm). n = 4; *p < 0.05 v. control. Error bars show s.e.m. Full length immunoblots are shown in Supplementary Fig. 3