Figure 3.

Acute exercise drives long-term increase in leucine uptake. (A) Intramuscular free leucine in SOL after exercise combined with leucine administration. (B) Intramuscular free leucine in SOL after exercise without leucine. (C) Fold change intramuscular free leucine in conditions where leucine was administered vs. no leucine (data derived from panel A and B). (D) Correlation between the increase in intramuscular free leucine (fold change versus Sed sal) and the increase in downstream mTORC1 signaling (pRPS6^Ser235/236 versus Sed sal). (G) qPCR of amino acid transporter genes in SOL in sed, Run0 and Run48 conditions without leucine. Quantification and representative immunoblot for SLC7A5 (LAT1) in SOL (E–F). (H) Experimental set-up to assess ¹⁴C leucine uptake. (I) Leucine uptake in m. soleus (SOL) and m. tibialis anterior (TA) after exercise and leucine supplementation. Bars represent mean, circles represent individual values, error bars represent standard error of mean (SEM). All data is shown as fold change to Sed sal (dashed horizontal line, when applicable). Panel A, (Sed sal n = 6), (Sed leu n = 6) (Run0 n = 6) (Run48 n = 6). Panel B, (Sed leu n = 4) (Run0 n = 6) (Run48 n = 4). Panel E, (Sed leu n = 5) (Run0 n = 6) (Run48 n = 4). Panel G, (Sed leu n = 6) (Run0 n = 6) (Run48 n = 5). Panel I, (Sed leu n = 5) (Run0 n = 6) (Run48 n = 5). One-Way ANOVA with Tukey's multiple comparisons test (panel A–D, G and I). ∗ p < 0.05; ∗∗ p < 0.01, ∗∗∗p < 0.001.