FIGURE 9.

Sevoflurane induced neuronal Parthanatos in hippocampus of neonatal rats (A) Representative images of hippocampal neurons stained by hematoxylin and eosin (HE) staining in P7 rat pups at 7 days after 2.5% sevoflurane exposure for 6 h. Scale bar = 50 μm. Compared to the control group, sevoflurane induced pyramidal neuron death (yellow arrow) in the hippocampal CA1 region, presenting in sparce and disordered arrangement of neurons, morphologically cell shrinkage, pink cytoplasm, and pyknotic nuclei, which were rescued by pretreatment with PAPR-1 inhibitor 3AB at 30 mg/kg or antioxidant NAC at 90 mg/kg intraperitoneally. (B) Statistical analysis of living neurons in hippocampal CA1 regions showed that pretreatment of 3AB or NAC significantly rescued sevoflurane-induced reduction of living neurons. (C–J,L–O) Western blotting and quantitative analysis showed that 2.5% sevoflurane for 6 h significantly upregulated the levels of cytoplasmic PAR polymer, PAPR-1, and AIF both in the cytoplasm and nucleus in the hippocampi of rat pups, which were markedly attenuated by pretreatment of 3AB or NAC. (K) The levels of ROS using ELISA method showed that 2.5% sevoflurane for 6 h significantly increased ROS overproduction in hippocampus of rat pups, which were markedly prevented by pretreatment with antioxidant NAC. (P,Q) Western blotting and quantitative analysis showed that 2.5% sevoflurane for 6 h significantly upregulated the levels of 8-OHdG, γH2AX, and p-ATM in hippocampi of rat pups, which were markedly attenuated by pretreatment of NAC. Compared with the control group, ^∗∗p < 0.01; Compared with sevoflurane group, significant differences were shown in rat pups pretreated with 3AB or NAC prior to sevoflurane exposure (p < 0.05, p < 0.01). Data are represented as mean ± SD from five independent experiments.