Figure 6.

Microsomal Ca²⁺ release triggered by selected HOCs of marine origin. (A) Schematic illustration showing the Ca²⁺ transport system monitored with Ca²⁺ dye Arsenozo III. (B) Representative traces of Ca²⁺ fluxes. Microsomal (JSR) vesicles were loaded with 4 sequential additions of 45 nmole CaCl₂, 60−90 s after the final bolus of Ca²⁺ was accumulated into vesicles, vehicle (0.2% DMSO, a) or test compounds (b or c) was introduced into one of the cuvettes. Ruthenium red (RR, 2 μM), a RyR blocker, was then added to each cuvettes to confirm the engagement of RyR1 followed by addition of SERCA inhibitor, cyclopiazonic acid (CPA, 50 μM), and CaCl₂ were added to calibrate absorbance unit into absolute Ca²⁺ in nmol. The Ca²⁺ release rate of initial 60 s upon the addition of Veh or test compounds (5 or 10 μM) are summarized in Panels C−H. Data shown are from 3 to 6 independent experiments using 2 different microsomal membrane preparations. Data expressed as Mean ± SD and one-way ANOVA followed by Dunnett’s multiple comparisons test was performed using Graph Pad 7.03. *p < 0.05, **p < 0.01 vs Veh. And n.s. indicates no significant difference compared with Veh.