Fig. 7.
Synaptosomes incubated at 4 or 37°C do not increase their uptake of [14C]acetate over time. The observed association of [14C] label at 37°C is not altered by addition of 10 mm CHC. Synaptosomal suspensions were incubated with 0.2 mm[14C]acetate alone at 4 or 37°C in the presence or absence of CHC. At the indicated times, aliquots of the suspension were diluted into cold buffer containing 10 mm CHC and immediately centrifuged through a layer of silicone oil at room temperature. Synaptosomes from the same preparation were kept on ice in 0.32 m sucrose until the acetate-uptake experiments were completed and then were incubated with 0.01 mm[14C]glutamate at 37°C. Data points represent the mean ± SD of five determinations. The 4°C experiment was repeated two additional times and the same results were obtained. There were no significant differences in [14C]acetate uptake between individual time points or between synaptosomes incubated with or without CHC.