Fig. 3. Targets of different drugs within the sympathetic nervous system that increase the availability of norepinephrine (NE) within the synaptic cleft (EGCG, ephedrine, amphetamine, sibutramine) or prolong NE-induced increases in lipid mobilization and oxidation (caffeine). Abbreviations: NE, norepinephrine; COMT, catechol-O-methyl transferase; ß-AR, ß-adrenoreceptor; Gs, stimulatory G-protein; PKA, protein kinase A; HSL, hormone sensitive lipase; TAG, triacylglycerol; FFA, free fatty acids; PDE, phosphodiesterase.