Ursodeoxycholic acid and endothelial-dependent, nitric oxide-independent vasodilatation of forearm resistance arteries in patients with coronary heart disease

Aims Ursodeoxycholic acid (UDCA) has cholesterol lowering and anti-inflamma tory effects and bile acids are reported to exert vasodilator effects, all of these properties might be considered desirable in a drug used in the tre atment of patients with coronary heart disease. We investigated a hypothesi s that UDCA may dilate arteries and the mechanism of action. Methods We evaluated effects of a 6-week treatment with UDCA in 11 coronary heart disease patients on endothelium-dependent (acetylcholine-induced) an d -independent (nitroprusside-induced) vasodilatations in forearm vasculatu re by strain-gauge plethysmography. Healthy individuals (n = 14) served as baseline controls. Results The percentage increase by acetylcholine in the flow of the infused arm relative to the non-infused arm of coronary heart disease patients dur ing the trial remained unaltered, but vasodilatation to NG-monomethyl-L-arg inine + acetylcholine was improved by 161 +/- 27% with UDCA vs 83 +/- 22% w ith placebo (mean difference 91% [95% CI 35%, 147%], P = 0.016). Conclusions Six weeks' UDCA therapy improved endothelium-dependent nitric o xide-independent vasodilatation, which might maintain arterial flow in coro nary heart disease patients under conditions of impaired nitric oxide produ ction.