Figure 4.

Characterization of intracellular pathways involved in the protective effect of Hb on astroglial cells. Cells were pre-incubated for 30 min in the absence or presence of H89 (2 × 10⁻⁵ M), chelerythrine (10⁻⁶ M; Chel), or U0126 (10⁻⁶ M) and then incubated for 24 h with medium alone () Hb (10⁻⁹ M) alone or with H₂O₂ (50 µM) in the absence () or presence of Hb (). (A) Cell death was determined by measuring LDH activity in culture media, and the results are expressed as percentage of LDH released in Triton-lysed cells. (B) Cell survival was quantified by measuring FDA fluorescence intensity, and the results are expressed as percentages of control. Data are means ± SEM of four independent experiments. ANOVA followed by Bonferroni’s test ***p < 0.001; NS, not statistically different from control cells. ^###p < 0.001; ns, not statistically different vs. H₂O₂-treated cells.