FIGURE 1.

Excess glucose and palmitate do not increase mitochondrial oxidative phosphorylation. Differentiated 3T3-L1 adipocytes were cultured for 7 days in low (5 mm) or high (25 mm) glucose media with or without added palmitate (250 μm) as indicated. A, ATP content was measured by an ATP assay kit. Oxygen consumption rate (B) and lactate production rate (LPR) (C) were measured using a flow culture system as described under “Experimental Procedures.” Oxygen consumption rate was measured in real time, and outflow samples were collected for lactate production rate and assayed for lactate, and the results were averaged over the duration of the experiment for the two separate conditions. *, p < 0.001 versus 5 mm glucose control.