Reactivity of LMAs from Wistar rats and SHRs with or without treatment to NOS inhibition with L-NAME and dilation to SNP. A, Percent constriction to the NO synthase inhibitor L-NAME (10−3 M) in LMAs isolated from Wistar rats, SHRs treated with hydralazine, captopril or vehicle. LMAs from all groups had similar vasoconstriction to L-NAME, data were analyzed by Kruskal-Wallis and Dunn’s test for multiple comparisons. Wistar: n=7; SHR-Hydral: n=6; SHR-Capto: n=7; SHR-Veh: n=8. B, Percent reactivity to the NO donor SNP in LMAs isolated from Wistar rats, and SHRs treated with hydralazine, captopril or vehicle. The concentration by group interaction was not significant [F(3, 170)=1.69, P>0.05], however, there were significant concentration effect and group effect [F(1, 170)=161.05, F(3, 25)=18.32; P<0.01]. **P<0.01 vs. All; ^^P<0.01 vs. Wistar and SHR-Capto by mixed model repeated measures ANOVA. Wistar: n=7; SHR-Hydral: n=6; SHR-Capto: n=8; SHR-Veh: n=8.