Early administration of YT-146, an adenosine A2 receptor agonist, inhibits neointimal thickening after rat femoral artery endothelium injury.

Adenosine is known to inhibit vascular smooth muscle cell proliferation in vitro via adenosine A2 receptor activation. We tested the inhibitory effect of an adenosine A2 receptor agonist, 2-octynyladenosine (YT-146), on in vivo intimal thickening following a photochemically induced injury of the endothelium of rat femoral artery. YT-146 (1 mg/kg/day) was administered s.c. for the first 3, 7 or 28 days after the injury. YT-146 significantly decreased neointimal area and the ratio of intima to medial area measured 28 days after the injury, regardless of the duration of administration. These results suggest that YT-146 may inhibit the early events of neointimal formation. The effect is long lasting and is not reversed even if YT-146 is stopped after a short course of administration.