Fig. 3. Histamine inhibits hypoxia-induced autophagy activation and apoptosis.

a H9c2 cells were treated with histamine at the indicated dose under hypoxia for 12 h. LC3 and p62 were detected by western blotting. b H9c2 cells were transfected with plasmids encoding GFP-LC3 for 8 h and then treated with histamine under hypoxia at the indicated dose for 12 h. Confocal microscopy was used to visualize the appearance of autophagosomes. The ratios of autophagic cells were calculated. Scale bar = 10 μm. c H9c2 cells were treated as a. The numbers of autophagic cells were analyzed by electron microscopy (red arrows, autophagic vacuoles). Scale bar = 500 nm. d H9c2 cells were treated as a. TUNEL assay was utilized to detect apoptosis. Quantitative analysis of apoptosis is shown at the right panel. N, nucleus; T, TUNEL-positive cells; M, merged. Results are representative of three independent experiments. *P < 0.05; **P < 0.01