Figure 3. Net VC uptake in cortical crude synaptosomes.

[A] Crude synaptosomes were incubated for 30 min without (control) and with 250 μM VC only or 250 μM VC and 10 min pre-incubation with 1 mM sulfinpyrazone and/or 0.1 mM phloretin. [B] Crude synaptosomes were pre-incubated for 10 min with 1 mM SPZ, 0.1 mM PHL, sodium-free KRH, 1 mM unlabeled VC, or 40 mM 3-O-methylglucose before the addition of ¹⁴C-VC (0.05 μCi, 7 μM) and further incubated for 30 min. [C] Crude synaptosomes were incubated with ¹⁴C-VC (0.05μCi, 7μM) for different periods of time or [D] for 10 min with increasing amounts of unlabeled VC. The calculated K_m and V_max were 18.3 ± 4.7 μM and 277 ± 28.1 nmol/g/30 min, respectively. The results represent the mean ± SEM (n=3). *P<0.05, compared control bar (far left) by one-way ANOVA with post-hoc testing.

SPZ, sulfinpyrazone; PHL, phloretin; VC, Vitamin C