Background:

CGS 21680 HCl is a selective agonist of A2 adenosine receptor with IC50 value of 22nM [1].

In rat striatal membranes, CGS 21680 potently prevents ligands from binding to A2 adenosine receptors with IC50 value of 22nM. In the binding assay, CGS 21680 shows no effect to other putative neurotransmitter/neuromodulator sites in brain membranes such as adrenergic, dopamine and serotonin. In the rat heart model, CGS 21680 is effective in increasing coronary flow with EC25 value of 2nM [1].

In vivo, the hydrochloride salt of CGS 21680 has potent efficacy to decrease blood pressure in the anesthetized normotensive rat with ED50 value of 9μg/kg. It also causes heart rate increasing up to 15%. Besides that, CGS 21680 HCl significantly lower the blood pressure at dose of 10mg/kg in the spontaneously hypertensive rat. A transient elecation of heart rate is also observed at 30 min in the model [1].

参考文献:
[1] Hutchison A J, Webb R L, Oei H H, et al. CGS 21680C, an A2 selective adenosine receptor agonist with preferential hypotensive activity. Journal of Pharmacology and Experimental Therapeutics, 1989, 251(1): 47-55.