Fig. 4.

Sample midwall circumferential strain (E_cc) vs. time curves from WT (top), eNOS^−/− (middle), and nNOS^−/− (bottom) mice at baseline and in response to infusion of Dob and Dob + CCh. In WT and eNOS^−/− mice, peak E_cc increased significantly from basal levels (dotted gray line) in response to Dob and returned to basal levels following administration of Dob + CCh. In nNOS^−/− mice, no change in E_cc was seen in response to either Dob or Dob + CCh.