Figure 4.

TCTP induced dopamine release from PC12 cells via Ca²⁺-independent pathways. [³H]Dopamine-preloaded PC12 cells were washed and treated in Ca²⁺-containing buffer (+Ca²⁺) or Ca²⁺-free buffer (−Ca²⁺) with 50 mM KCl, 1 µM bradykinin, and 50 µg/mL MrTCTP (A); [³H]Dopamine-preloaded PC12 cells were washed, pretreated for 20 min at 37 °C with 10 or 50 µM BAPTA-AM (B); 2 μM nifedipine (C); or 10 μM dantrolene (D); and then treated for 20 min with 50 µg/mL MrTCTP with the continued presence of above agent where indicated, in the basal and the high K⁺ (50 mM KCl) buffers. [³H]Dopamine release into media is expressed as relative to total [³H]dopamine loaded. Data are presented as Mean ± S.E.M. (standard error of mean) * p < 0.05 relative to control basal release; † p < 0.05 relative to control high K⁺ release; # p < 0.05 relative to respective basal release.