Normalized Ca2+ responses of OX1 and OX2 receptors to orexin-A and orexin-B in normal and low extracellular Ca2+
| 1 mM [Ca2+]e | 140 nM [Ca2+]e | |||
|---|---|---|---|---|
| Max (×ctrl) | EC50 (×ctrl) | Max (×ctrl) | EC50 (×ctrl) | |
| OX1 | ||||
| Orexin-A | 1.0 ± 0.1 | 1.0 ± 0.1 | 1.1 ± 0.1 | 14 ± 33-a |
| Orexin-B | 0.90 ± 0.04 | 6.9 ± 1.83-a | 0.87 ± 0.063-b | 46 ± 93-c 3-d |
| OX2 | ||||
| Orexin-A | 1.0 ± 0.1 | 1.0 ± 0.2 | 1.1 ± 0.13-a | 10 ± 23-a |
| Orexin-B | 0.76 ± 0.033-a | 1.0 ± 0.2 | 0.80 ± 0.073-e | 6.3 ± 0.93-b 3-c |
The data from the same experiments as in Table 3 were normalized to the response to orexin-A in 1 mM [Ca2+]e in each batch of cells.
↵3-a Significantly different (P < 0.001) compared with orexin-A in 1 mM [Ca2+]e.
↵3-b Significantly different (P < 0.05) compared with orexin-A in 140 nM [Ca2+]e.
↵3-c Significantly different (P < 0.001) compared with orexin-B in 1 mM [Ca2+]e.
↵3-d Significantly different (P < 0.001) compared with orexin-A in 140 nM [Ca2+]e.
↵3-e Significantly different (P < 0.01) compared with orexin-A in 140 nM [Ca2+]e. All the other reasonable comparisons yielded nonsignificant results.