OPC-28326 is a specific an α2-adrenergic receptor antagonist and acts as a peripheral vasodilator. OPC-28326 inhibits α2A-, α2B- and α2C-adrenoceptors with Ki of 2040, 285, and 55 nM, respectively.

Adenosine A1 receptor activator T62 is an allosteric enhancer of adenosine A1 receptor, and it produces antinociception in animal models of acute pain and also reduces hypersensitivity in models of inflammatory and nerve-injury pain[1][2][3].

Medetomidine (Domtor) is a potent, highly selective α2-adrenoceptor agonist, demonstrating Ki values of 1.08 nM for α2-adrenoceptors and 1750 nM for α1-adrenoceptors, indicating significant selectivity for α2 over α1 receptors compared to clonidine and UK 14,304 with 1620-, 220-, and 300-fold respectively. Medetomidine significantly inhibits the twitch response in electrically stimulated mouse vas deferens (pD2 = 9.0), showcasing its efficacy. Exhibiting a wide range of pharmacological effects, Medetomidine is effective in vivo, manifesting hypotensive, bradycardic, sedative, anxiolytic, hypothermic, and analgesic properties.

Moxonidine Hydrochloride serves as a selective agonist for the imidazoline receptor subtype 1 and functions as an antihypertensive agent. It primarily acts within the central nervous system and demonstrates a significant preference for I1 imidazoline receptors over α2-adrenoceptors, with a 40-fold higher affinity. This compound effectively reduces stimulated norepinephrine overflow, indicating its potent efficacy. Despite similar agents like AGN192403 targeting the same receptor, moxonidine's dose-response efficacy remains unaffected. Its ability to lower blood pressure and reduce heart rate is distinctly mediated through imidazoline receptors, reliant on well-preserved noradrenergic pathways within the rostral ventrolateral medulla (RVLM). This interaction is potentially linked to a specific 42 kDa imidazoline receptor protein, emphasizing its unique mechanism of action compared to other drugs like clonidine.

Piribedil hydrochloride can be used in the parkinson's disease, circulatory disorders, cancers research. Piribedil hydrochloride inhibits MLL1 methyltransferase activity with EC50 value of 0.18 μM. Piribedil hydrochloride is a potent and orally active agonist of dopamine D2 and dopamine D3 as well as the antagonist of α2-adrenoceptors [1] [2] [3] [4].

(E)-Guanabenz ((E)-Wy-8678), an oral central α2-adrenoceptor agonist, exhibits antihypertensive and neuroprotective activities by stimulating central α2-adrenoceptors to reduce sympathetic outflow and directly inhibiting GADD34, respectively. It is used in researching hypertension and Parkinson's disease [1] [2].