Effect of various solvents on binding of Bn-like peptides or PD 168368 to Bn receptor subtypes
| Receptor/Cell Line | Ki | ||
|---|---|---|---|
| Cyclodextrin | DMSO | Buffer | |
| nM | |||
| hGRP-R/BALB | |||
| Bn | 1.6 ± 0.8 | 2.4 ± 1.1 | 1.4 ± 0.2 |
| PD 168368 | 1200 ± 90 | 3400 ± 4001-a | N.D. |
| hNMB-R/BALB | |||
| NMB | 2.4 ± 0.3 | 3.0 ± 0.4 | 1.3 ± 0.2 |
| PD 168368 | 30 ± 2.0 | 160 ± 201-b | >30,000 |
| hBRS-3/BALB | |||
| [d-Phe6,β-Ala11,Phe13,Nle14]Bn(6–14) | 2.7 ± 0.4 | 3.9 ± 1.7 | 2.1 ± 0.8 |
| PD 168368 | >10,000 | >10,000 | N.D. |
BALB 3T3 cells transfected with human GRP, NMB, or BRS-3 receptors were incubated with 75 pM of their respective radioligand as described inExperimental Procedures for 45 min with either Bn, NMB, [d-Phe6,β-Ala11,Phe13,Nle14]Bn(6–14), or PD 168368 in binding buffer alone; binding buffer containing 0.5% cyclodextrin (v/v); or 0.3% DMSO (v/v) vehicles. Increasing concentrations of unlabeled peptide or PD 168368 were added with the same final concentration of vehicle in all cases, and the dose-inhibition curves were analyzed by least-squares curve fitting program. Ki values were calculated according to the method of Cheng-Prusoff and are the mean ± S.E.M. from at least three experiments performed in duplicate.