The endothelin-1 receptor antagonist bosentan protects against ischaemia/reperfusion-induced endothelial dysfunction in humans.
Endothelial dysfunction may contribute to the extent of ischaemia/reperfusion injury. ET (endothelin)-1 receptor antagonism protects against myocardial ischaemia/reperfusion injury in animal models. The present study investigated whether oral administration of an ET(A)/ET(B) receptor antagonist protects against ischaemia/reperfusion-induced endothelial dysfunction in humans. FBF (forearm blood flow) was measured with venous occlusion plethysmography in 13 healthy male subjects. Forearm ischaemia was induced for 20 min followed by 60 min of reperfusion. Using a cross-over protocol, the subjects were randomized to oral administration of 500 mg of bosentan or placebo 2 h before ischaemia. Endothelium-dependent and -independent vasodilatation were determined by intra-brachial infusion of acetylcholine (1-10 microg/min) and nitroprusside (0.3-3 microg/min) respectively, before and after ischaemia. Compared with pre-ischaemia, the endothelium-dependent increase in FBF was significantly impaired at 15 and 30 min of reperfusion when the subjects received placebo (P<0.01). When the subjects received bosentan, the endothelium-dependent increase in FBF was not affected by ischaemia/reperfusion. Endothelium-independent vasodilatation was not affected during reperfusion compared with pre-ischaemia. The vaso-constrictor response induced by intra-arterial infusion of ET-1 was attenuated significantly by bosentan (P<0.001). The results suggest that the dual ET(A)/ET(B) receptor antagonist bosentan attenuates ischaemia/reperfusion-induced endothelial dysfunction in humans in vivo. Bosentan may thus be a feasible therapeutic agent in the treatment of ischaemia/reperfusion injury in humans.
Böhm
Felix
F
Department of Cardiology, Karolinska University Hospital Solna, S-171 76 Stockholm, Sweden.
Settergren
Magnus
M
Gonon
Adrian T
AT
Pernow
John
J
D000328:Adult; D000077300:Bosentan; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D065130:Endothelin A Receptor Antagonists; D019332:Endothelin-1 / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000503:physiopathology; D005542:Forearm / Q000098:blood supply; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D008297:Male; D010991:Plethysmography / Q000379:methods; D012039:Regional Blood Flow / Q000187:drug effects; D015427:Reperfusion Injury / Q000503:physiopathology / Q000517:prevention & control*; D013449:Sulfonamides / Q000627:therapeutic use*; D014664:Vasodilation / Q000187:drug effects
D065130:Endothelin A Receptor Antagonists; D019332:Endothelin-1; D013449:Sulfonamides; D000077300:Bosentan