Figure 7.

Effect of leptin and tumor necrosis factor-α (TNF-α) upon ¹⁴C-l-methionine (¹⁴C-l-Met) uptake by Bewo cells. (A) Cells were exposed to 1, 100, 300, or 1000 ng/mL leptin or the respective solvent (control; corresponding to 100%) for 1 to 72 hours, and initial rates of uptake were then determined by incubating cells for 6 minutes at 37°C with 250 nmol/L ¹⁴C-l-Met (n = 5-13); (B) cells were exposed to 100, 300, or 1000 ng/L TNF-α or the respective solvent (control; corresponding to 100%) for 1 to 48 hours, and initial rates of uptake were then determined by incubating cells for 6 minutes at 37°C with 250 nmol/L ¹⁴C-l-Met (n = 5-16). Shown is arithmetic mean ± standard error of the mean. *Significantly different from control (P < .05) and ^#significantly different from leptin (1 ng/mL; P < .05).