Fig. 1

Transport activity of system y⁺L in monocytes from three LPI patients. Left Panels. Monocytes from healthy donors and LPI patients carrying different mutations of SLC7A7 were obtained as described in “Materials and Methods” (Panels a, b and c show results obtained for cont₁ vs LPI₁, cont₂ vs LPI₂, and cont₃ vs LPI₃, respectively). After a wash in EBSS, arginine uptake was assayed by 1-min incubation in the same solution supplemented with L-[³H]-arginine (50 μM; 4 μCi/ml) either in the absence or in the presence of 2 mM Leucine (see Methods). Data are means ± SD of four independent determinations in a representative experiment, repeated twice for each subject with comparable results. Right Panels. Data shown in left Panels were employed to calculate the relative contribution of system y⁺L as the difference between total transport and transport measured in the presence of leucine (see Methods). *p < 0.05, **p < 0.01 vs. control