Table 2. Relative potencies of AdA analogues at different IP₃ receptor subtypes.

	IP3R1	IP3R2	IP3R3
IP3	1.02±0.02	0.9±0.30	1.1±0.30
Imidophostin	0.78±0.15	0.78±0.08	0.81±0.04
Ribophostin	0.82±0.18	0.96±0.20	1.06±0.07
Furanophostin	0.92±0.13	0.83±0.14	1.25±0.05
Manno-AdA	0.74±0.08	0.79±0.18	0.98±0.08
Xylo-AdA	−0.01±0.07	−0.3±0.27	0.05±0.08
2′-dephospho-AdA	1.24±0.33	1.60±0.18	1.68±0.16
3″-dephospho-AdAa	4.03±0.09	4.47±0.30	4.13±0.14

From paired comparisons with AdA, the potency (ΔpEC₅₀) of the analogues relative to AdA is shown for each IP₃R subtype. Results are means ± SEM, with n provided in Table 1. ND, not determined. ^aBecause the very low affinity of 3″-dephospho AdA for IP₃R made it impracticable to stimulate cells with a maximally effective concentration, ‘ΔpEC₅₀’ for 3″-dephospho AdA was estimated by comparing concentrations of it and AdA that evoked the same sub-maximal Ca²⁺ release.