α-adrenoceptors

L-Albizziin (2-Methoxyidazoxan monohydrochloride) is a highly potent selective antagonist of the alpha 2r adrenergic receptor, with little or no antagonistic effect on imidazoline. It has a significantly higher affinity for the alpha 2D adrenergic receptor (pKd9.7) in guinea pigs than for the alpha 2A adrenergic receptor (pKd8.2) in rabbits.

(±)-Tazifylline is a selective and long-acting antagonist of histamine H1 receptor. Tazifylline shows much lower affinity for H2 receptors, α- and β-adrenoceptors, 5-hydroxytryptamine and muscarinic receptor subtypes.

L-745870 trihydrochloride is a highly potent and selective D4 dopamine receptor antagonist.

(S)-Terazosin is an active S-enantiomer of Terazosin and acts as a potent, high-affinity antagonist of α-adrenoceptors [α1a, α1b, and α1d-adrenoceptors] with Ki values of 3.91 nM, 0.79 nM, and 1.16 nM, respectively.

Dobutamine, a synthetic catecholamine, increases cardiac output and corrects hypoperfusion. It acts on α1-AR, β1-AR, and β2-AR (α-1, β-1, and β-2 adrenoceptors) with selective agonist activity on β1-AR and relatively weak activity at α1-AR and β2-AR. [1] [2] [3] [4].