Fig. 7

Expression levels of TLR4, NK-1, and Na⁺/K⁺-ATPase were studied using Western blot analysis. Astrocytes were cultivated in 5.5 mM glucose the whole cultivation period. The cells were incubated with LPS (10 ng/ml) for 24 h, when incubated with LPS for 24 h followed by LPS, 25 mM glucose, a combination of naloxone (Nal) (10^− 12 M), endomorphin-1 (EM-1) (10^− 6 M), and levetiracetam (Lev) (10^− 4 M), or a combination of sildenafil (Sild) (1 μM) and vitamin D3 (D3) (100 nM), or combination of all substances for another 24 h. Unstimulated cells were used as controls. The level of significance was calculated against LPS (5.5) and analyzed using one-way ANOVA followed by Dunnett’s multiple comparisons test. *P < 0.05, **P < 0.01, ***P < 0.001. n = 6. Representative images of Western blot membranes are presented. Additional data, small histograms below, show LPS + glucose, LPS + glucose + sildenafil, LPS + glucose + vitamin D3, and LPS + glucose + sildenafil + vitamin D3