Fig. 10. The rates of Ca2+ removal following depolarization- and InsP3-induced increases in [Ca2+]c were reduced by 8-bromo cADPR. (A) The membrane permeable cADPR antagonist, 8-bromo cADPR (20 µM, added to the bath), significantly slowed the rate of Ca2+ removal following the increases in [Ca2+]c (ai and bi) produced either by InsP3 (
, ai,iii; n=6) or depolarization (70 mV to +10 mV, bi,iii; n=6). (B) Inhibition of Ca2+ removal mechanisms [ii; mitochondria, SR Ca2+ pump and Na+-Ca2+ exchange using CCCP and oligomycin (OL) Na+-free bathing solution (NaF) and thapsigargin (TG) together] significantly slowed the rate of decline following depolarization-evoked (60 mV to +10 mV) [Ca2+]c increases. Thereafter, 8-bromo-cADPR was added (iii) in the continued presence of the removal inhibitors; this increased the baseline [Ca2+]c and slowed further the rate of [Ca2+]c decline (notice the increased time base on iii) (summarised in Bb) (*P<0.05; n=5-7 for each data point).