(A) Depolarization (60 mmol/L K+ KRB)-induced, and (B) induced contraction in MAs derived from wt (white bars), Trx-Tg (blue bars) and dnTrx-Tg (red bars) mice. MAs derived from wild-type (circles), Trx-Tg (upward triangles) and dnTrx-Tg (downward triangles) mice were assessed for: (C) Endothelium-dependent relaxations to cumulative concentrations of ACh. (D) Endothelium-independent relaxations in MAs pretreated with L-NAME and indomethacin (INDO) contracted with a submaximal concentration of PHE, and assessed with cumulative concentrations of SNP. (E) NO-mediated endothelium-dependent relaxations in MAs pretreated for 30 min with INDO the IK1 channel blocker TRAM-34 and the SK3 channel blocker UCL-1684, to block EDH-mediated responses, contracted with PHE before assessing relaxing responses to cumulative concentrations of ACh. (F) Endothelium-dependent hyperpolarizing (EDH) responses in MAs treated with the NO synthase blocker L-NAME and INDO followed by cumulative concentrations of ACh. Values are means ± SEM (n=8–10 mice). * P< 0.05 Trx-Tg compared with wt, # P< 0.05 dnTrx-Tg compared with wtand Trx-Tg, ** P< 0.05 Trx-Tg compared with wtand dnTrx-Tg.