Effect of indometacin, NS398, furegrelate and tranylcypromin on vasodilation response to Ach. Cumulative concentration curves were obtained in aortic rings isolated from AIA, nor-NOHA AIA and control rats 21 days after the onset of arthritis. Cumulative concentration curves with Ach were obtained after a 60-minute incubation period with indometacin at 10-5 moles/liter or with NS398 at 10-4 moles/liter in controls (A), AIA (C) and nor-NOHA AIA (E) or with furegrelate at 10-6 moles/liter or with tranylcypromine at 10-5 moles/liter in controls (B), AIA (D) and nor-NOHA AIA (F). Values are the mean ± SEM from 8 to 12 aortic rings. * = P <0.05.