Condition | MPP+ Uptake | ||||
---|---|---|---|---|---|
15 sec | 30 sec | 60 sec | 2 min | 60 min | |
nmol/mg protein | |||||
5 mM TEAin | 15.9 ± 1.7* | 25.1 ± 4.1* | 20.8 ± 3.1* | 22.3 ± 1.3** | 31.8 ± 4.0 |
0 mM TEAin | 10.8 ± 0.9 | 12.9 ± 0.8 | 11.4 ± 0.8 | 12.2 ± 2.0 | 28.9 ± 2.3 |
Membrane vesicles were incubated with 250 mM sucrose, 10 mM HEPES/Tris, pH 7.4, 0.2 mM CaCl2, in the presence or absence of 5 mM TEA, for 60 min at 25°C. Uptake over time was measured at 25°C in medium containing 250 mM sucrose, 10 mM HEPES/Tris, pH 7.4, and 0.2 mM CaCl2. Extravesicular medium contained 1 mM [3H]MPP+ and 1 mM TEA at time 0. Data are expressed as means ± S.E. of triplicate analyses of five different membrane vesicle preparations.
* P < .05.
** P < .005.