OBJECTIVE: To observe the neuroprotective effect of 6-shogaol (6-SH) in global cerebral ischemia/reperfusion injury (CIRI) following cardiac arrest (CA) and cardiopulmonary resuscitation (CPR) in rats. METHODS: Computer-aided molecular docking was used to determine whether 6-SH could spontaneously bind to death-associated protein kinase 1 (DAPK1). SPF-grade male SD rats were randomly divided into a sham group (n = 5), a CPR group (n = 7), and a CPR+6-SH group (n = 7). The CPR group and CPR+6-SH group were further divided into 12-, 24-, and 48-hour subgroups based on observation time points. A rat model of global CIRI after CA-CPR was established by asphyxiation. In the sham group, only tracheal and vascular intubation was performed without asphyxia and CPR induction. The CPR group was intraperitoneally injected with 1 mL of normal saline immediately after successful modeling. The CPR+6-SH group received an intraperitoneal injection of 20 mg/kg 6-SH (1 mL) immediately after successful modeling, followed by administration every 12 hours until the endpoint. Neurological Deficit Score (NDS) was recorded at each time point after modeling. After completion of observation at each time point, rats were anesthetized and sacrificed, and brain tissue specimens were collected. Histopathological changes of neurons were observed under light microscopy after hematoxylin-eosin (HE) staining. Ultrastructural changes of hippocampal neurons and autophagy were observed by transmission electron microscopy (TEM). Real-time quantitative polymerase chain reaction (RT-qPCR) was used to detect mRNA expression levels of DAPK1, vacuolar protein sorting 34 (VPS34), Beclin1, and microtubule-associated protein 1 light chain 3 (LC3) in brain tissues. Western blotting was used to detect protein expression levels of DAPK1, phosphorylated DAPK1 at serine 308 (p-DAPK1 ser308), VPS34, Beclin1, and LC3. Immunofluorescence was used to observe Beclin1 and LC3 expression in brain tissues under a fluorescence microscope. RESULTS: Molecular docking results indicated that 6-SH could spontaneously bind to DAPK1. Compared with the sham group, the NDS scores of the CPR group rats were significantly increased at all modeling time points; under light microscopy, disordered cell arrangement, widened intercellular spaces, and edema were observed in brain tissues, with pyknotic and necrotic nuclei in some areas; under TEM, mitochondria were markedly swollen with intact membranes, dissolved matrix, reduced or disappeared cristae, vacuolization, and increased autophagosomes. Compared with the CPR group, the NDS scores of the CPR+6-SH group rats were significantly decreased at all modeling time points; under light microscopy, local neuronal edema and widened perinuclear space were observed; under TEM, mitochondria were mostly mildly swollen with intact membranes, fewer autophagosomes, and alleviated injury. RT-qPCR results showed that compared with the sham group, mRNA expression levels of DAPK1, VPS34, Beclin1, and LC3 in brain tissues were significantly upregulated in all CPR subgroups, with the most pronounced changes at 24 hours. Compared with the CPR group, the CPR+6-SH group showed significantly lower mRNA expression of the above indicators at each time point [24 hours post-modeling (relative expression): DAPK1 mRNA: 3.41±0.68 vs. 4.48±0.62; VPS34 mRNA: 3.63±0.49 vs. 4.66±1.18; Beclin1 mRNA: 3.08±0.49 vs. 4.04±0.22; LC3 mRNA: 2.60±0.36 vs. 3.67±0.62; all P < 0.05]. Western blotting results showed that compared with the sham group, the protein expression levels of DAPK1, VPS34, Beclin1, and LC3 in all CPR subgroups were significantly increased, while the expression of p-DAPK1 ser308 was significantly decreased, with the most pronounced changes observed in the CPR 24-hour subgroup. Compared with the CPR group, the CPR+6-SH subgroups exhibited significantly reduced protein expression of DAPK1, VPS34, Beclin1, and LC3 [24-hour post-modeling: DAPK1/β-actin: 1.88±0.22 vs. 2.47±0.22; VPS34/β-actin: 2.55±0.06 vs. 3.46±0.05; Beclin1/β-actin: 2.12±0.03 vs. 2.87±0.03; LC3/β-actin: 2.03±0.24 vs. 3.17±0.23; all P < 0.05]. Conversely, the expression of p-DAPK1 ser308 was significantly upregulated in the CPR+6-SH group compared to the CPR group [24-hour post-modeling: p-DAPK1 ser308/β-actin: 0.40±0.02 vs. 0.20±0.07, P < 0.05]. Under the fluorescence microscope, fluorescence intensities of Beclin1 and LC3 in the CPR 24-hour group were significantly higher than those in the sham 24-hour group; compared with the CPR 24-hour group, the CPR+6-SH 24-hour group showed significantly reduced fluorescence intensities of Beclin1 and LC3. CONCLUSION 6-SH inhibited the expression of DAPK1, alleviated excessive autophagy after global CIRI following CA-CPR in rats, and exerted neuroprotective effects. The mechanism may be related to phosphorylation at the DAPK1 ser308 site.
Animals ; Rats, Sprague-Dawley ; Male ; Rats ; Cardiopulmonary Resuscitation ; Autophagy/drug effects* ; Heart Arrest/therapy* ; Death-Associated Protein Kinases/metabolism* ; Reperfusion Injury/metabolism* ; Disease Models, Animal ; Neuroprotective Agents/pharmacology* ; Brain Ischemia/metabolism*

BackgroundThe incidence of cancer, diabetes, and autoimmune diseases has been increasing. Furthermore, there are more and more patients with solid organ transplants. The survival rate of these immunocompromised individuals is extremely low when they are severely hit-on. In this study, we established cardiac arrest cardiopulmonary resuscitation (CPR) model in severe combined immunodeficient (SCID) mice, analyzed the expression and activation of mitochondrial autophagy and NLRP3 inflammasome/caspase-1, and explored mitochondrial repair and inflammatory injury in immunodeficiency individual during systemic ischemia-reperfusion injury.

MethodsA potassium chloride-induced cardiac arrest model was established in C57BL/6 and nonobese diabetic/SCID (NOD/SCID) mice. One hundred male C57BL/6 mice and 100 male NOD/SCID mice were randomly divided into five groups (control, 2 h post-CPR, 12 h post-CPR, 24 h post-CPR, and 48 h post-CPR). A temporal dynamic view of alveolar epithelial cells, macrophages, and neutrophils from bronchoalveolar lavage fluid (BALF) was obtained using Giemsa staining. Spatial characterization of phenotypic analysis of macrophages in the lung interstitial tissue was analyzed by flow cytometry. The morphological changes of mitochondria 48 h after CPR were studied by transmission electron microscopy and quantified according to the Flameng grading system. Western blotting analysis was used to detect the expression and activation of the markers of mitochondrial autophagy, NLRP3 inflammasome, and caspase-1.

Results(1) In NOD/SCID mice, macrophages were disintegrated in BALF, and many alveolar epithelial cells were shed at 48 h after resuscitation. Compared with C57BL/6 mice, the ratio of macrophages/total cells peaked at 12 h and was significantly higher in NOD/SCID mice (31.17 ± 4.13 vs. 49.69 ± 2.43, t = 14.46, P = 0.001). After 24 h, the results showed a downward trend. Furthermore, a large number of macrophages were disintegrated in the BALF. (2) Mitochondrial autophagy was present in both C57BL/6 and NOD/SCID mice after CPR, but it began late in the NOD/SCID mice. Compared with C57BL/6 mice, phos-ULK1 (Ser) expression was significantly lower at 2 h and 12 h after CPR (2 h after CPR: 1.88 ± 0.36 vs. 1.12 ± 0.11, t = -1.36, P < 0.01 and 12 h after CPR: 1.52 ± 0.16 vs. 1.05 ± 0.12, t = -0.33, P < 0.01), whereas phos-ULK1 (Ser) expression was significantly higher at 2 h and 12 h after CPR in NOD/SCID mice (2 h after CPR: 1.28 ± 0.12 vs. 1.69 ± 0.14, t = 1.7, P < 0.01 and 12 h after CPR: 1.33 ± 0.10 vs. 1.94 ± 0.13, t = 2.75, P < 0.01). (3) Furthermore, NLRP3 inflammasome/caspase-1 activation in the pulmonary tissues occurred early and for only a short time in C57BL/6 mice, but this phenomenon was sustained in NOD/SCID mice. The expression of the NLRP3 inflammasome increased modestly in the C57 mice, but the increase was higher in the NOD/SCID mice than in the C57BL/6 mice, especially at 12, 24, 48 h after CPR (48 h after CPR: 1.46 ± 0.13 vs. 2.97 ± 0.19, t = 5.34, P = 0.001). The expression of caspase-1-20 generally followed the same pattern as the NLRP3 inflammasome.

ConclusionsThere is a regulatory relationship between the NLRP3 inflammasome and mitochondrial autophagy after CPR in the healthy mice. This regulatory relationship was disturbed in the NOD/SCID mice because the signals for mitochondrial autophagy occurred late, and NLRP3 inflammasome- and caspase-1-dependent cell injury was sustained.

Animals ; Autophagy ; physiology ; Heart Arrest ; metabolism ; physiopathology ; Inflammasomes ; metabolism ; Lung ; metabolism ; physiopathology ; Macrophages ; metabolism ; physiology ; Male ; Mice ; Mice, Inbred C57BL ; Mice, Inbred NOD ; Mice, SCID ; Mitochondria ; metabolism ; NLR Family, Pyrin Domain-Containing 3 Protein ; metabolism

To investigate the changes of myocardial glucose metabolism in rabbit cardiac arrest models and the effect of hydrogen intervention by 18F-fluroro-2-deoxyglucose (18F-FDG) positron emission tomography (PET) imaging.
 Methods: Fifteen male New Zealand white rabbits were randomly divided into a hydrogen group (n=6), a control group (n=6) and a sham group (n=3). Cardiac arrest (CA) was induced by intravenous injection of potassium chloride. Conventional cardiopulmonary resuscitation (CPR) was initiated after five-minutes CA. The hydrogen group and the control group were mechanically ventilated into mixed gas with 4% hydrogen+96% oxygen and pure oxygen, respectively, for 30 minutes after CPR. Rats in the sham group was performed the same surgical procedure and was injected adrenaline and potassium chloride but did not induce CA. The vital signs at basic state and 30 min after return of spontaneous circulation (ROSC) were recorded in each group. The parameters of CPR were recorded in two CA groups. Myocardial glucose metabolism was assessed by positron emission tomography (PET) at basic state, 2 h and 24 h after ROSC. The maximum standardized uptake value (SUVmax) of 18F-FDG was measured.
 Results: There were no significant differences in the basal body weight and vital signs among the three groups. There was no significant difference in the blood glucose level before PET examination. The 18F-FDG SUVmax in the sham group at three time points was not significantly changed. In the hydrogen group and the control group, the 18F-FDG SUVmax at 2 h after ROSC were significantly higher than the basic level (1.89±0.47 vs 3.47±1.24 and 1.90±0.36 vs 4.26±0.80, respectively). Compared with the control group, the 18F-FDG SUVmax in the hydrogen group was lower at the point at 2 h after ROSC. The 18F-FDG SUVmax in the 2 CA group were down to the basic level at 24 h after ROSC (hydrogen group 2.02±0.64, control group 2.07±0.61).
 Conclusion: Myocardial glucose metabolism in CA rabbits was increased significantly after ROSC, and hydrogen intervention can reduce the degree of glucose metabolism.
Animals ; Cardiopulmonary Resuscitation ; Glucose ; metabolism ; Heart Arrest ; physiopathology ; surgery ; Male ; Myocardium ; metabolism ; Positron-Emission Tomography ; Rabbits ; Random Allocation ; Rats

Phosphate is essential in regulating human metabolic processes, and severe hypophosphatemia can induce neurologic and hematological complications and result in respiratory failure and cardiac dysfunction. Therefore, correction of severe hypophosphatemia can be pivotal in the management of diabetic ketoacidosis (DKA). We report the case of a 14-year-old female who was diagnosed with type 1 diabetes and referred to our institute for treatment of DKA. Although the patient received fluid and continuous insulin administration according to the current DKA treatment protocol, generalized tonic seizures and cardiac arrest developed. After cardiopulmonary resuscitation, the patient recovered and was stable. Within 16 hours after DKA treatment, the patient developed respiratory failure with severe hypophosphatemia that required mechanical ventilation. Concurrent neurologic evaluation revealed no specific abnormalities. The patient recovered without any complications after correcting the hypophosphatemia. We suggest vigilant monitoring of the phosphate level in DKA patients and active replacement when required.
Adolescent ; Cardiopulmonary Resuscitation ; Clinical Protocols ; Diabetic Ketoacidosis* ; Female ; Heart Arrest ; Humans ; Hypophosphatemia* ; Insulin ; Metabolism ; Respiration, Artificial ; Respiratory Insufficiency* ; Seizures

OBJECTIVETo investigate the effects of Shenfu Injection (, SFI) on cerebral metabolism in a porcine model of cardiac arrest (CA).

METHODSThirty Wuzhishan minipigs were randomly assigned to the control group (n=6), epinephrine group (EP group, n=12) and Sfigroup (n=12). After 8 min of untreated ventricular fifibrillation (VF), pigs in the EP group or Sfigroup were administered with either EP (0.02 mg/kg) or Sfi(1.0 mL/kg), respectively. After successful resuscitation, cerebrospinal fluid (CSF) levels of glucose, pyruvate, lactate, glutamate and glycerol were measured at 1, 6, 12 and 24 h after recover from spontaneous circulation (ROSC). In addition, neurologic defificit score (NDS) was calculated at 24 h after ROSC. Surviving pigs were killed at 24 h after ROSC, and the brain tissue was obtained for ultra-microstructure examination.

RESULTSCompared with the EP group, CSF glucose and pyruvate levels were higher (all P<0.01), and lactate levels were lower in the Sfigroup (P<0.01). Meanwhile, CSF glutamate and glycerol levels in the Sfigroup were lower in comparison to the EP group (all P<0.05). In addition, Sfidecreased NDS at 24 h after ROSC (P<0.01), and alleviated the histopathological damage of the brain.

CONCLUSIONSSficould alleviate brain injury after CA, which may be associated with improving cerebral metabolism.

Animals ; Blood Circulation ; Blood Gas Analysis ; Brain ; drug effects ; metabolism ; ultrastructure ; Cardiopulmonary Resuscitation ; Disease Models, Animal ; Drugs, Chinese Herbal ; administration & dosage ; pharmacology ; therapeutic use ; Heart Arrest ; cerebrospinal fluid ; drug therapy ; physiopathology ; Injections ; Jugular Veins ; drug effects ; metabolism ; Perfusion ; Sus scrofa

OBJECTIVETo investigate whether Shen-Fu Injection (, SFI) reduces post-resuscitation immune dysfunction in a porcine model of cardiac arrest by modulating apoptosis of regulatory T lymphocytes (Treg) in the spleen.

METHODSAfter 8-min untreated ventricular fibrillation and 2-min basic life support, 24 pigs were divided into 3 groups with a random number table, i.e. SFI group, epinephrine (EP) group, and saline (SA) group (8 in each group), which received central venous injection of SFI (1.0 mL/kg), EP (0.02 mg/kg) and SA, respectively. The same procedure without CA initiation was achieved in the sham-operated (sham) group (n=6). After successful return of spontaneous circulation (ROSC), apoptosis rate of splenic Treg was detected by flow cytometry; and the mRNA expression of forkhead/winged helix transcription factor (Foxp3) of splenic Treg was detected by real time-polymerase chain reaction; and the levels of interleukin-4 (IL-4) and interferon-γ (IFN-γ) in porcine splenic Treg were detected by using enzyme-linked immunosorbent assay (ELISA).

RESULTSCompared with the sham group, the apoptosis rate of Treg was significantly decreased, and the levels of Foxp3 mRNA expression, IFN-γ, IL-4 and IFN-γ/IL-4 were increased in the SA group (P<0.05 or P<0.01). Compared with the EP and SA groups, SFI treatment increased the apoptosis rate of Treg and reduced the levels of Foxp3 mRNA expression, IFN-γ and IFN-γ/IL-4 (P<0.05).

CONCLUSIONSSFI has signifificant effects in attenuating post-resuscitation immune dysfunction by modulating apoptosis of Treg in the spleen.

Animals ; Apoptosis ; drug effects ; Cardiopulmonary Resuscitation ; Disease Models, Animal ; Drugs, Chinese Herbal ; administration & dosage ; pharmacology ; therapeutic use ; Forkhead Transcription Factors ; genetics ; metabolism ; Heart Arrest ; drug therapy ; immunology ; pathology ; physiopathology ; Hemodynamics ; drug effects ; Injections ; Interferon-gamma ; metabolism ; Interleukin-4 ; metabolism ; Lymphocyte Subsets ; drug effects ; metabolism ; Male ; Oxygen ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Spleen ; immunology ; Survival Analysis ; Swine ; Swine, Miniature ; T-Lymphocytes, Regulatory ; drug effects ; immunology

BACKGROUNDPostresuscitation immune dysfunction contributes to the low survival rate after successful resuscitation, but its mechanism remains poorly understood. The purpose of this study was to investigate whether splenic regulatory T-cell (Treg) apoptosis was involved in the postresuscitation immune dysfunction.

METHODSThirty-eight pigs were randomly divided into sham-operated group (SHAM group, n = 8), 12 h post return of spontaneous circulation (ROSC) group, 24 h post-ROSC group, and 48 h post-ROSC group (n = 10 per group). A Wuzhishan miniature porcine model of 8-min ventricular fibrillation cardiac arrest (CA) was established. The apoptosis rates of Treg in the spleen were tested by flow cytometry; the expressions of forkhead/winged helix transcription factor (Foxp3) of Treg in the spleen were detected by real-time polymerase chain reaction; and the levels of interleukin-4 (IL-4), IL-10, and interferon gamma (IFN-γ) of Treg in the spleen were detected by enzyme-linked immunosorbent assay.

RESULTSThe apoptosis rates of Treg in all post-ROSC groups were significantly lower than that of SHAM group (7.7% ± 1.9%, 7.1% ± 1.8%, 6.2% ± 0.4% vs. 13.1% ± 1.6%; P < 0.05); the expression levels of Foxp3 and IL-10 were also decreased with the increase of apoptosis rates of Treg. Helper T-cells CD4+ lymphocyte subsets were significantly lower in the post-ROSC groups compared with SHAM group (29.1% ± 2.2%, 24.3% ± 2.2%, 24.1% ± 2.5% vs. 43.8% ± 4.5%; P < 0.01) at 12, 24, and 48 h after ROSC. Compared with SHAM group, the levels of IFN-γ (161.0 ± 12.9, 167.7 ± 10.5, 191.2 ± 7.7 vs. 7.6 ± 0.9 ng/L) and IL-4 (27.7 ± 6.2, 35.9 ± 3.5, 50.6 ± 6.1 vs. 13.3 ± 2.3 ng/L) and the ratio of IFN-γ/IL-4 (8.6 ± 2.3, 4.9 ± 0.4, 4.5 ± 0.9 vs. 0.8 ± 0.2) were all greatly elevated in all post-ROSC groups (P < 0.05).

CONCLUSIONSApoptosis rate of Treg was significantly decreased after CA, and thus the proportion of Treg was increased and the inhibitory effects were enhanced, which further led to the decrease of the amount of CD4+ T-cells. In addition, the T helper type 2/T helper type 1 (Th2/Th1) cell drift of Treg in the spleen caused postresuscitation immune dysfunction.

Animals ; Apoptosis ; physiology ; Cardiopulmonary Resuscitation ; Disease Models, Animal ; Enzyme-Linked Immunosorbent Assay ; Flow Cytometry ; Forkhead Transcription Factors ; metabolism ; Heart Arrest ; immunology ; metabolism ; Interferon-gamma ; metabolism ; Interleukin-4 ; metabolism ; Random Allocation ; Spleen ; cytology ; Swine ; Swine, Miniature ; T-Lymphocytes, Regulatory ; cytology ; metabolism ; physiology ; Ventricular Fibrillation ; complications ; metabolism

BACKGROUNDMorbidity and mortality after resuscitation largely depend on the recovery of brain function. Ventricular fibrillation cardiac arrest (VFCA) and asphyxial cardiac arrest (ACA) are the two most prevalent causes of sudden cardiac death. Up to now, most studies have focused on VFCA. However, results from the two models have been largely variable. So, it is necessary to characterize the features of postresuscitation cerebral metabolism of both models.

METHODSForty-four Wuzhishan miniature inbred pigs were randomly divided into three groups: 18 for VFCA group, ACA group, respectively, and other 8 for sham-operated group (SHAM). VFCA was induced by programmed electric stimulation, and ACA was induced by endotracheal tube clamping. After 8 min without treatment, standard cardiopulmonary resuscitation (CPR) was initiated. Following neurological deficit scores (NDS) were evaluated at 24 h after achievement of spontaneous circulation, cerebral metabolism showed as the maximum standardized uptake value (SUVmax) was measured by 18 F-fluorodeoxyglucose positron emission tomography/computed tomography. Levels of serum markers of brain injury, neuron specific enolase (NSE), and S100β were quantified with an enzyme-linked immunosorbent assay.

RESULTSCompared with VFCA group, fewer ACA animals achieved restoration of spontaneous circulation (61.1% vs. 94.4%, P < 0.01) and survived 24-h after resuscitation (38.9% vs. 77.8%, P < 0.01) with worse neurological outcome (NDS: 244.3 ± 15.3 vs. 168.8 ± 9.71, P < 0.01). The CPR duration of ACA group was longer than that of VFCA group (8.1 ± 1.2 min vs. 4.5 ± 1.1 min, P < 0.01). Cerebral energy metabolism showed as SUVmax in ACA was lower than in VFCA (P < 0.05 or P < 0.01). Higher serum biomarkers of brain damage (NSE, S100β) were found in ACA than VFCA after resuscitation (P < 0.01).

CONCLUSIONSCompared with VFCA, ACA causes more severe cerebral metabolism injuries with less successful resuscitation and worse neurological outcome.

Animals ; Asphyxia ; complications ; physiopathology ; Brain ; metabolism ; Cardiopulmonary Resuscitation ; Heart Arrest ; metabolism ; pathology ; therapy ; Positron-Emission Tomography ; Swine ; Ventricular Fibrillation ; metabolism ; pathology ; therapy

The possible role of minocycline in microglial activation and neuronal death after cardiac arrest (CA) and cardiopulmonary resuscitation (CPR) in mice was investigated in this study. The mice were given potassium chloride to stop the heart beating for 8 min to achieve CA, and they were subsequently resuscitated with epinephrine and chest compressions. Forty adult C57BL/6 male mice were divided into 4 groups (n=10 each): sham-operated group, CA/CPR group, CA/CPR+minocycline group, and CA/CPR+vehicle group. Animals in the latter two groups were intraperitoneally injected with minocycline (50 mg/kg) or vehicle (normal saline) 30 min after recovery of spontaneous circulation (ROSC). Twenty-four h after CA/CPR, the brains were removed for histological evaluation of the hippocampus. Microglial activation was evaluated by detecting the expression of ionized calcium-binding adapter molecule-1 (Iba1) by immunohistochemistry. Neuronal death was analyzed by hematoxylin and eosin (H&E) staining and the levels of tumor necrosis factor-alpha (TNF-α) in the hippocampus were measured by enzyme-linked immunosorbent assay (ELISA). The results showed that the neuronal death was aggravated, most microglia were activated and TNF-α levels were enhanced in the hippocampus CA1 region of mice subjected to CA/CPR as compared with those in the sham-operated group (P<0.05). Administration with minocycline 30 min after ROSC could significantly decrease the microglial response, TNF-α levels and neuronal death (P<0.05). It was concluded that early administration with minocycline has a strong therapeutic potential for CA/CPR-induced brain injury.
Animals ; Cardiopulmonary Resuscitation ; Cell Death ; drug effects ; Enzyme-Linked Immunosorbent Assay ; Heart Arrest ; pathology ; Hippocampus ; cytology ; drug effects ; metabolism ; Male ; Mice ; Mice, Inbred C57BL ; Microglia ; cytology ; drug effects ; Minocycline ; pharmacology ; Neurons ; drug effects ; Tumor Necrosis Factor-alpha ; metabolism

BACKGROUNDToll-like receptor 4 (TLR4) is a crucial receptor in the innate immune system and noninfectious immune responses. It has been reported that TLR4 participates in the pathological course of ischemia/reperfusion (I/R) injury. However, the role of TLR4 in the process of I/R injury after cardiac arrest (CA) and cardiopulmonary resuscitation (CPR) is still unknown. In this study, we investigated the effects of TLR4 mutation on survival and neurological outcome in a mouse model of CA/CPR.

METHODSA model of potassium-induced CA was performed on TLR4-mutant mice (C3H/HeJ) and wild-type mice (C3H/HeN). After 3 min of untreated CA, resuscitation was attempted with chest compression, ventilation, and intravenous epinephrine. Behavioral tests were performed on mice on day 3 after CPR. The morphological changes in hippocampal neurons were assessed by light and electron microscopy. Expressions of TLR4 and intercellular adhesion molecule-1 (ICAM-1) were detected by Western blot. Levels of tumor necrosis factor-α (TNF-α) and myeloperoxidase (MPO) were measured with enzyme-linked immunosorbent assay (ELISA).

RESULTSOn day 3 after resuscitation the overall mortality was 33.33% in C3H/HeJ group compared with 53.33% in C3H/HeN group (P < 0.05). And there was much higher central tendency in C3H/HeJ group than C3H/HeN group during open field test (P < 0.05). Meanwhile, the percentage of nonviable neurons was 21.16% in C3H/HeJ group compared with 53.11% in C3H/HeN group (P < 0.05). And there were significantly lower levels of hippocampal TNF-α and MPO in C3H/HeJ mice (TNF-α: 6.85±1.19 ng/mL, MPO: 0.33±0.11 U/g) than C3H/HeN mice (TNF-α: 11.36±2.12 ng/mL, MPO: 0.54±0.17 U/g) (all P < 0.01). CPR also significantly increased the expressions of TLR4 and ICAM-1 in C3H/HeN group. However, the expression of ICAM-1 was much lower in C3H/HeJ group than in C3H/HeN group after CPR (P < 0.01).

CONCLUSIONTLR4 signaling is involved in brain damage and in inflammation triggered by CA/CPR.

Animals ; Blotting, Western ; Brain ; immunology ; metabolism ; Cardiopulmonary Resuscitation ; methods ; Heart Arrest ; genetics ; metabolism ; therapy ; Intercellular Adhesion Molecule-1 ; metabolism ; Male ; Mice ; Mutation ; Peroxidase ; metabolism ; Toll-Like Receptor 4 ; genetics ; metabolism ; Tumor Necrosis Factor-alpha ; metabolism