Figure 2.

Inhibition by SKF-89976A of [³H]-GABA uptake by rat GP synaptosomes. Synaptosomes were incubated for 4 min with [³H]-GABA/GABA (50 nM/3 μM) in the absence and presence of the indicated concentrations of the inhibitor SKF-89976A, added 10 min before. (A) Representative experiment. Values are means ± SEM from three replicates. Nonspecific uptake was determined in parallel samples incubated at 4 °C. (B) Analysis of the concentration–response curve for SKF-89976A. [³H]-GABA uptake is expressed as percentage of control values after subtraction of nonspecific uptake. Values are means ± SEM of three replicates from the experiment shown in panel (A). The curve drawn is the best-fit adjust to a logistic equation. The IC₅₀ value is given in the text.