Fig. 3
Astrocytes were stimulated, in a fluorescence-based assay for detecting changes in intracellular Ca2+ over time, with the following: 5-HT (10−5 M), glutamate (10−3 M), or ATP (10−4 M). The cells were cultivated in 5.5 mM or 25 mM glucose the whole cultivation period. Ca2+ responses when incubated with LPS (10 ng/ml) for 24 h, or when incubated with LPS for 24 h followed by LPS and sildenafil (Sild) (1 μM); unstimulated cells were used as controls ©. The area under the Ca2+ peak (AUC) was calculated for each Ca2+ transient, and the amplitude (peak) was expressed as the maximum increase. The cells were obtained from three experiments with quadruple wells in each. 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. Separate small histograms show cells cultivated in 5.5 mM glucose and 25 mM glucose, respectively. The level of significance was calculated against LPS (5.5) or against LPS (25). *P < 0.05