Figure 3.

Effects of xestospongin-C on high-K⁺-stimulated [Ca²⁺]_i (upper tracing) and muscle tension (lower tracing) in ileal smooth muscle. When [Ca²⁺]_i and muscle tension induced with high K⁺ reached a steady state level, 3 (A) or 10 (B) μM xestospongin-C and 10 μM verapamil were added sequentially. (C) Summarized data on (A) and (B) (n=6). In (C), 100% represents high K⁺-induced increases in [Ca²⁺]_i and force at steady state before the addition of xestospongin-C. Values were obtained 20–30 min after the addition of 3 μM xestospongin-C and 15 min after the addition of 10 μM xestospongin-C. **P < 0.01 vs control.