Figure 4.

Percent Na⁺-dependent uptake of 50 uM [³H]-Thr remaining in the presence of the indicated amino acid (500 uM) (A) after subtraction of uptake in 140 mM Choline Cl. A 1-sample t-test confirmed that all amino acids tested were s significant inhibitors (^*p < 0.05). A one-way ANOVA indicated no statistically significant difference in [³H]-Thr uptake in the presence of the different amino acids tested (p > 0.05) (n = 4 for each column; 2 determinations obtained in each of 2 independent experiments). (B) Percent uptake of [³H]-Thr remaining in the presence of the indicated amino acid (500 uM) but without subtraction of Na⁺-independent transport. A 1-sample t-test confirmed that all amino acids were statistically significant inhibitors (^*p < 0.05). A one-way ANOVA indicated no statistically significant difference in [³H]-Thr uptake in the presence of the different amino acids tested (p > 0.05) (n = 4 for each column; 3 determinations obtained in each of 2 independent experiments).