Figure 5.

Concentration response curves showing the changes in tone induced by (a) tiron, (b) PTIYO and (c) tempol on phenylephrine-contracted, endothelium-containing rings of rat aorta (control). The effects of pretreatment with L-NAME (100 μM; 30 min) and of endothelial removal (−EC) on these changes are also shown. Each point is the mean±s.e.mean of 8–18 observations. ^***P<0.001 and ###P<0.001 indicate a significant difference following treatment with L-NAME and following endothelial removal, respectively.