Fig 2: P2X7R expression and microglial activation in the PVN of AMI rats. A Representative image of immunohistochemistry of Iba-1-ir cells (brown) (scale bars, left 200 μm; right 50 μm). B Fluorescence images of microglia immunostained for anti-OX42 (cd11b/c) in the PVN from Sham, AMI, and BBG + AMI rats (scale bars, 50 μm). C Numbers of Iba-1-ir cells in the PVN. D Mean densitometry of OX42 (cd11b/c) immuno-positivity. E Representative immunoblot bands of P2X7R, pro-IL-1β, and IL-1β in the PVN in the different groups. F–H Optical density analysis of P2X7R (F), pro-IL-1β (G) and IL-1β (H) immunoblotting bands. I Double immunofluorescence showing co-localization of P2X7R and Iba-1 analyzed by confocal fluorescence microscopy (scale bars, 20 μm). J Quantitative analysis of fluorescence intensity of P2X7R and Iba-1 staining in microglia from the groups. K Levels of co-localization of P2X7R and Iba-1 assessed using the Pearson coefficient. Data are expressed as the mean ± SEM. **P < 0.01 versus Sham group, #P < 0.05 versus AMI group.

Fig 3: Effects of the P2X7R antagonist BBG on NOX2 expression and ROS production in the PVN of AMI rats. A Representative images of western blots showing protein expression of NOX2. B Histogram of protein levels relative to GAPDH levels. C Representative images showing the enhanced DHE fluorescence in the PVN of AMI compared with sham rats and those with other treatments (scale bars, 20 μm). D Mean NADPH-dependent O2− production in the PVN of different groups. Data are presented as the mean ± SEM. **P < 0.01, *P < 0.05 versus Sham group, ##P < 0.01, #P < 0.05 versus AMI group.

Fig 4: Schematic displaying that PVN P2X7R activation aggravates acute myocardial injury via ROS-induced vasopressin-V1b activation in AMI rats.