Figure 6.
Effect of perfusion with 20 μM T1AM on SR calcium release determined using the quick filtration technique. Left panel: maximum release rate, measured after passive loading with 10 mM 45Ca and exposure to 18 μM unlabelled calcium. Right panel: passive leak measured after active loading with 45Ca and exposure to 1 mM EGTA, 10 mM MgCl2 and 0.3 mM tetracaine. The figures show vescicle radioactivity, expressed as percentage of the baseline value, at different filtration times (note the different time scale between the two panels). Data represent mean ± S.E.M. obtained in three different preparations. Exponential fitting yielded a significant difference in the rate constant for the right panel (P < 0.01). See text for analytical results.