Figure 6. Interactions of (1,4,6)IP₃ with IP₃ receptor subtypes.

(A) Structures of (1,4,5)IP₃ and (1,4,6)IP₃ drawn to show how they differ only in the relative orientations of the 2- and 3-hydroxyl groups of (1,4,5)IP₃. (B) Effects of (1,4,6)IP₃ on Ca²⁺ release via each IP₃R subtype. (C) Paired comparisons of the effects of (1,4,5)IP₃ and (1,4,6)IP₃ are shown for each IP₃R subtype. Results (B and C) are means ± SEM from the number of independent experiments given in Table 1.