Comparison of the effects of specific inhibitors Nω-nitro-L-arginine (LNA, inhibitor of nitric oxide synthase) and indomethacin (INDO, inhibitor of cyclooxygenase) on contraction-relaxation vascular responses in aortas of WT (CB1R+/+) and CB1R KO (CB1R−/−) female mice. Panel (A). Effects of inhibitor LNA on Phe-induced vasoconstriction in CB1R+/+ (n = 6, segments = 6) and CB1R−/− (n = 6, segments = 6) female mice. Panel (B). Effects of inhibitor INDO on Phe-induced vasoconstriction in CB1R+/+ (n = 5, segments = 5) and CB1R−/− (n = 6, segments = 6) female mice. Panel (C). Effects of inhibitor LNA on Ach-induced vasorelaxation in CB1R+/+ (n = 8, segments = 8) and CB1R−/− (n = 8, segments = 8) female mice. Panel (D). Effects of inhibitor INDO on Ach-induced vasodilation in CB1R+/+ (n = 8, segments = 8) and CB1R−/− (n = 8, segments = 8) female mice. Panel (E). Effects of inhibitor LNA on E2 induced vascular responses in CB1R+/+ (n = 9) and CB1R−/− (n = 8) female mice. Panel (F). Effects of inhibitor INDO on E2-induced vascular responses in CB1R+/+ (n = 9) and CB1R−/− (n = 9) female mice. Differences in contraction or relaxation values are plotted. Panel (G). Normalized effects of INDO on E2 relaxation responses (at 10 µmol/L). Values are plotted as percentage differences from control relaxation. Mean ± SEM values. p < 0.05 values were considered significant. * p < 0.05 between CB1R+/+ and CB1R−/− groups (two-way ANOVA with a Bonferroni post hoc test). Abbreviations: Ach: acetylcholine, Phe: phenylephrine, E2: estradiol, INDO: indomethacin, LNA: Nω-nitro-L-arginine, CB1R: cannabinoid type 1 receptor, WT: wild-type, KO: knockout, CB1R+/+: cannabinoid type 1 receptor wild-type mice, CB1R−/−: cannabinoid type 1 receptor knockout mice.