Drug affinities at MDCK cell alpha-1 adrenoceptors
| Competitor | Hill slope | −log Ki |
|---|---|---|
| 5-Methylurapidil | 1.04 ± 0.02 | 7.37 ± 0.14 |
| Epinephrine | 0.83 ± 0.03 | 6.38 ± 0.07 |
| Methoxamine | 0.99 ± 0.04 | 4.34 ± 0.21 |
| Norepinephrine | 0.91 ± 0.09 | 6.79 ± 0.28 |
| Oxymetazoline | 1.06 ± 0.03 | 6.77 ± 0.04 |
| Phentolamine | 1.35 ± 0.27 | 8.27 ± 0.04 |
| SDZ NVI-085 | 1.16 ± 0.06 | 5.16 ± 0.03 |
| (−)-Tamsulosin | 0.98 ± 0.09 | 9.78 ± 0.03 |
| (+)-Tamsulosin | 1.04 ± 0.06 | 7.82 ± 0.06 |
None of the drugs had competition curves that were significantly better explained by a two- than a one-site model; agonist competition curves (epinephrine, methoxamine, norepinephrine, oxymetazoline, SDZ NVI-085) were performed in the presence of 100 μM GTP.
Data are mean ± SEM of 3 or 4 experiments.