Ability of PD 168368 to inhibit increases in [Ca2+]istimulated by activation of NMB-Rs, GRP-Rs, BRS-3, and BB4receptors
| Receptor | [Ca2+]i | |||||
|---|---|---|---|---|---|---|
| Basal | Buffer | PD 168368 Alone | Agonist | |||
| Agonist Alone | Plus PD 168368 | |||||
| nM | nM increase | nM increase | % agonist alone | |||
| rNMB-R/C6 | 36 ± 2 | 3 ± 1 | 0 ± 1 | 286 ± 175-a | 10 ± 25-b | 4 ± 1 |
| rNMB-R/BALB | 127 ± 1 | 1 ± 1 | 1 ± 1 | 355 ± 45-a | 82 ± 45-b | 23 ± 1 |
| hNMB-R/BALB | 81 ± 17 | 3 ± 1 | 2 ± 1 | 432 ± 815-a | 157 ± 355-b | 36 ± 4 |
| mGRP-R/BALB | 90 ± 10 | 6 ± 2 | 1 ± 1 | 750 ± 305-a | 356 ± 335-b | 47 ± 3 |
| hGRP-R/BALB | 81 ± 13 | 4 ± 2 | 0 ± 1 | 808 ± 1315-a | 404 ± 895-b | 58 ± 12 |
| hBRS-3/NCI-N417 | 39 ± 13 | 10 ± 1 | 2 ± 1 | 186 ± 415-a | 161 ± 31 | 88 ± 5 |
| hBRS-3/BALB | 116 ± 12 | 2 ± 1 | 7 ± 4 | 473 ± 605-a | 442 ± 57 | 97 ± 17 |
| fBB4/CHO-K1 | 96 ± 6 | 7 ± 1 | 3 ± 2 | 409 ± 765-a | 412 ± 77 | 100 ± 6 |
Cells expressing NMB-Rs, GRP-Rs, hBRS-3, or BB4 receptors were incubated with 100 nM NMB, Bn, [d-Phe6,β-Ala11,Phe13,Nle14]Bn(6–14), or [Phe13]Bn, respectively, with or without 4 μM PD 168368 in 0.5% cyclodextrin (v/v). hNMB-R-transfected BALB 3T3 cells were incubated with 10 nM NMB, which gave a comparable rise in [Ca2+]i to that seen with the other cells containing NMB-Rs. Percentage of agonist alone represents the percent of [Ca2+]i mobilized in the presence of agonist and 4 μM PD 168368 compared with the agonist alone. Results are expressed as mean ± S.E.M. from at least three experiments performed in duplicate.