Table 1

Pharmacological characterization of α1-adrenoceptor subtypes

Potency ordernoradrenaline = adrenaline1-a
Selective agonists A61603
Selective antagonistsKMD 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).