Figure 1. Time course of plasma membrane Calcium²+-ATPase (PMCA) transport of Calcium²+ into synaptic plasma membrane (SPM) vesicles prepared from cerebra of control (unanesthetized) rats (C), rats anesthetized with halothane 1 MED (minimum effective dose) for 20 min (A), and rats recovered (R) from anesthesia. Data (means) were derived from six separate experiments, with membranes pooled from three to eight rats and incubated in quadruplicate. The vertical axis denotes Calcium sup 2+ uptake (nmoles *symbol* mg protein sup -1) and the horizontal axis incubation time (minutes). Treatment groups are indicated by open columns (C), hatched columns (A), and cross-hatched columns (R). Solid columns in the foreground demonstrate the inhibitory effect of 0.1 mM orthovanadate on PMCA pumping activity for all treatment groups. Error bars indicate 95% confidence limits for the mean derived from ANOVA. Methods are described in the text.