Fig 2: The changes of melatonin receptors and their related proteins in sleep-deprived mice after being treated with ramelteon, SMC, as well as melatonin receptor antagonists luzindole and 4-P-PDOT (n = 3). (A) Western blotting results. Statistical data of the MT1 levels (B), the MT2 levels (C), the OX1R levels (D), the OX2R levels (E), the Per1 levels (F), the clock levels (G), the CaMK? levels (H), and the p-CREB levels (I). *p < 0.05 vs. control group; #p < 0.05 vs. model group; @p < 0.05 vs. SMC group. All the data were represented as the mean ± SD.

Fig 3: Gene expression of orexin receptors. DOCA-salt treatment significantly increased (A) OX1R and (B) OX2R mRNA in the brain hypothalamic PVN of WT mice, which was prevented in B1RKO mice with DOCA-salt hypertension. Statistical significance: Two-way ANOVA followed by Tukey’s multiple comparisons test. *p < 0.05 versus WT + Sham; †p < 0.05 versus WT + DOCA; n = 6/group.

Fig 4: Orexin protein expression of orexin receptors within PVN. DOCA-salt treatment significantly increased (A) OX1R and (B) OX2R protein expression in the brain hypothalamic PVN of WT mice, which was prevented in B1RKO mice with DOCA-salt hypertension. Statistical significance: Two-way ANOVA followed by Tukey’s multiple comparisons test. *p < 0.05 versus WT + Sham; †p < 0.05 versus WT + DOCA; n = 6/group. (C) Triple immunofluorescence staining of OXR1 (green) and OXR2 (magenta) along with neuronal anatomical marker vasopressin (red) reveals OX1R and OX2R staining co-localized with PVN neurons as pointed by arrows.