Protective effect of shen-fu injection on neuronal mitochondrial function in a porcine model of prolonged cardiac arrest

Abstract

Background. Shen-Fu injection (SFI) following cardiac arrest exhibits neurological effects, but its effect on neurological dysfunction is unclear. This study sought to investigate the protective effect of SFI on nerve cells in a porcine model of cardiac arrest. Methods. After eight minutes of untreated ventricular fibrillation (VF) and 2 minutes of basic life support, 24 pigs were randomized and divided into three cardiopulmonary resuscitation groups, which received central venous injection of either Shen-Fu (SFI group; 1.0 ml/kg), epinephrine (EP group; 0.02 mg/kg), or saline (SA group). Surviving pigs were sacrificed at 24 h after ROSC and brains were removed for analysis for morphologic changes of mitochondria by electron microscopy, for mitochondrial transmembrane potential (MTP) by flow cytometry, and for opening of the mitochondrial permeability transition pore (MPTP) by mitochondrial light scattering. Results. Compared with the EP and SA groups, SFI treatment reduced opening of MPTP, showing higher MMP. In addition, animals treated with SFI showed slight cerebral ultrastructure damage under the electron microscopy. Conclusion. Shen-Fu injection alleviated brain injury, improved neurological ultrastructure, stabilized membrane potential, and inhibited opening of MPTP. Therefore, SFI could significantly attenuate postresuscitation cerebral ischemia and reperfusion injury by modulating mitochondrial dysfunction of nerve cells.

Figure 1

Cumulative survival in the sham and CPR (SA, EP, and SFI) groups. There were no significant differences in 6- and 24-hour survival rates between CPR groups.

Figure 2

(a) Mean aortic pressure (MAP); (b) cardiac output (CO); the values are reported as mean (SD), ^* P < 0.05, and ^# P < 0.01 versus sham; ^▲ P > 0.05 and ^# P < 0.01 versus EP (one-way repeated-measures ANOVA).

Figure 3

MMP are expressed as mean ± SEM (n = 6 in SHAM group and CPR groups). Quantitative data for MMP were significantly lower in the CPR subgroups than in the SHAM group (^•• P < 0.01); MMP was significantly higher in the SFI group than in the SA group (⁺⁺ P < 0.01); MMP was significantly higher in the SFI group than in the EP group (^△ P < 0.05).

Figure 4

Changes of MPTP in pig cerebral cortex nerve cell. Mitochondria light density was significantly lower in all CPR groups than SHAM group at 24 hours after ROSC. In addition, the degree of opening of MPTP in SFI group is lighter than that in SA and EP group.

Figure 5

Cytoplasmic ultrastructure of the brain neuron under an electron microscope. (a) Normal cells structure of the brain neuron was observed in the SHAM group (arrows). (b) Ischemic pig brain cells ultrastructures in the SA group at 24 hours after cardiac resuscitation. Dotted arrows display brain glial cell nucleus damage, and the arrow shows mitochondrial swelling. (c) At 24 h after cardiac resuscitation in the EP group, mitochondrial architecture of brain neuron became more severe. (d) Mitochondrial architecture exhibited little intracellular damage in the SFI group at 24 hours after cardiac resuscitation.