Figure 3. Na⁺ dependency of Hcy inhibition of [³H]l–Arg uptake into MVM vesicles.

Effect of l–Hcy (A), dl–Hcy (B) and l–Met (C) as positive control on 0.2 μm[³H]l–Arg uptake by MVM vesicles in the presence (▪) or absence (▴) of an inwardly directed Na⁺ gradient at initial rate (30 s). Data are mean ±s.e.m. (n= 6) and were fitted by non-linear regression to a one-site binding model.