Pharmacological characterization of α1-adrenoceptor subtypes
| α1A | α1B | α1D | |
|---|---|---|---|
| Potency order | noradrenaline = adrenaline1-a | ||
| Selective agonists | A61603 | ||
| Selective antagonists | KMD 3213 (10.4) | AH 11110A (7.1) | BM Y7378 (8.4) |
| (+)-Niguldipine (10.0) | Chloroethylclonidine1-b | ||
| SNAP 5089 (9.7) | |||
| 5-Methylurapidil (9.2) | |||
| RS 17053 (9.2) | |||
| SNAP 5272 (8.4) |
Antagonist affinities (number in parentheses) are expressed as approximate −log K i values.
↵1-a Both noradrenaline and adrenaline have about 10-fold higher affinity for α1D- than for α1A- and α1B-adrenoceptors.
↵1-b Although the rank order of α1-adrenoceptor subtype inactivation by chloroethylclonidine is α1B ≥ α1D> α1A, chloroethylclonidine can inactivate all α1-adrenoceptor subtypes depending on concentration and time, temperature, and medium for incubation. Adapted from Alexander and Peters (1999).