Figure 4.

Roles of ryanodine receptors (RyR) and IP₃ receptors (IP₃R) in caffeine‐stimulated duodenal epithelial anion secretion. (a–c) Representative time courses and summary data showing the effect of LiCl (30 mM, n = 8) on carbachol (CCh)‐ or caffeine (Caf)‐stimulated I _sc after mucosal and serosal (m + s) addition. (d–f) Representative time courses and summary data showing the effect of ruthenium red (RR, 1 mM, n = 9) on carbachol‐ or caffeine‐stimulated I _sc after mucosal and serosal addition. (g) Representative time courses and summary data showing the effect of dantrolene (Dan, 100 μM, n = 6) on carbachol‐stimulated I _sc after serosal (s) addition. (h) Representative time courses and summary data showing the effect of dantrolene (Dan, 100 μM, 300 μM, 1 mM, n = 6 for each) on caffeine‐stimulated I _sc after mucosal (m) or serosal (s) addition. ns: no significant differences, ^* P < 0.05, significantly different from the corresponding control