Figure 6. Effects of veratridine on intracellular free Ca²⁺ ([Ca²⁺]_i) and intracellular free Na⁺ ([Na⁺]_i) levels in human sperm cells.

(A,B) For [Ca²⁺]_i measurement, cells were loaded with Fura-2 and responses to veratridine (10 μM) were determined in the presence of (A) the Na _v1.8 antibody ab-66743 (dilution 1:50) (red line) or its solvent (black line) or (B) in the presence of the Na _v1.8 antagonist A-803467 (1 μM) (red line) or its solvent (black line). The X axis shows time in seconds and the Y axis shows [Ca²⁺]_i data expressed by the F340/F380 ratio. Traces are representative of typical results obtained in 5-7 different experiments for each blocker. (C) For [Na⁺]_i measurement, cells were loaded with SBFI and responses to veratridine (10 μM) were determined in the presence of A-803467 (1 μM) (red line) or its solvent (black line). The X axis shows time in seconds and the Y axis shows [Na⁺]_i data expressed by the F340/F385 ratio. Traces are representative of typical results obtained in 6 different experiments.