Figure 2. Effect of isoflurane on endothelium-dependent relaxation induced by SIN-1 (endothelium-denuded) in canine pulmonary arteries. Arterial rings were contracted to the ED50level of tension with phenylephrine. Relaxations are expressed as percentages of phenylephrine contraction (n = 5). Isoflurane had no effect on acetylcholine-induced (n = 5) or SIN-1-induced (n = 5) vasorelaxation.