Abstract 595: Functional, Histologic, and Radiographic Characteristics of Global Ischemia-reperfusion Brain Injury in a Mouse Model Of Cardiac Arrest

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Akshay Pendyal ◽  
Cameron Dezfulian ◽  
Luhua Zhang ◽  
Jeeva Munasinghe ◽  
Mark T Gladwin

Cardiac arrest (CA) and subsequent CPR constitute a clinically relevant form of global ischemia-reperfusion injury (IR). Global IR often results in widespread ischemic brain damage and severe neurologic sequelae. In the present study, we sought to describe the functional, histologic, and radiographic brain changes that occur following CA/CPR. 8–10 week old C57BL/6 mice were subjected to 12 minutes of normothermic cardioplegic CA and resuscitated with chest compressions, mechanical ventilation, and epinephrine. Sham mice underwent surgery, but not CA. At 3 and 24 hours, 10-point functional neurological score and rectal temperature were assessed prior to trans-cardiac perfusion with PBS and 10% buffered formalin. Sectioned brains were stained using hematoxylin and eosin (H/E) and the terminal deoxyuridine triphosphate nick end-labeling (TUNEL) technique. An additional cohort of mice underwent quantitative diffusion MRI at 24 and 72 hours, gadolinium (Gd)-enhanced MRI at 24 hours, and quantitative T2 imaging at 72 hours. Compared to shams, mice undergoing CA/CPR displayed significantly lower functional neurological score at 3 hours (3±2 vs. 10±0; P<.001) and 24 hours (8±1 vs. 10±0, P<.05), and significantly higher rectal temperature at 3 hours (35.8±1.5 vs. 34.1±0.8, P<.001) and lower rectal temperature at 24 hours (33.8±2.5 vs. 37.1±0.8, P=.08). TUNEL and H/E staining revealed injury in the cortex, thalamus, hippocampus, and cerebellum, but neither a consistent pattern nor clear temporal progression was observed. Gd-enhanced MRI revealed increased signal intensity, particularly in the cortex, after CA (3.7×105±0.96×105 vs. 0.66×105±0.017×105, P<.05), consistent with breakdown of the blood-brain barrier. Diffusion MRI revealed a strong trend towards globally decreasing diffusion coefficients at 24 and 72 hours (P=0.14), consistent with widespread cell death. In our model of CA, global IR results in poor neurological function and global injury by MRI that is not reflected by early histology. MRI thus appears to be a more sensitive measure of visualizing neurological injury in the early stages after CA and may predict the delayed neuronal death remarked upon by other authors.

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Jiefeng Xu ◽  
Sen Ye ◽  
Zilong Li ◽  
Moli Wang ◽  
Zhengquan Wang ◽  
...  

Introduction: Systemic ischemia-reperfusion injury produced by CA and resuscitation can result in severe post-cardiac arrest syndrome; which includes systemic inflammatory response and multiple organ dysfunction syndrome such as acute pulmonary edema. We previously demonstrated that remote ischemic post-conditioning (RIpostC) improved post-resuscitation myocardial and cerebral function in a rat model of CA. In this study, we investigated the effects of RIpostC on inflammatory response and pulmonary edema after CPR in a porcine model. Hypothesis: RIpostC would alleviate post-resuscitation inflammatory response and pulmonary edema in a porcine model of CA. Methods: Fourteen male domestic pigs weighing 37 ± 2 kg were utilized. Ventricular fibrillation was electrically induced and untreated for 10 mins. The animals were then randomized to receive RIpostC or control. Coincident with the start of CPR, RIpostC was induced by four cycles of 5 mins of limb ischemia and then 5 mins of reperfusion. Defibrillation was attempted after 5 mins of CPR. The resuscitated animals were monitored for 4 hrs and observed for an additional 68 hrs. Results: Six of the seven animals in each group were successfully resuscitated. After resuscitation, significantly lower levels of tumor necrosis factor-α and interleukin-6 were measured in the animals that received RIpostC when compared with the control group. Post-resuscitation extra-vascular lung water index was lower in the RIpostC group than in the control group; in which the differences were significant at 2,3 and 4 hrs (Table). Conclusion: In a porcine model of CA, RIpostC significantly alleviates post-resuscitation inflammatory response and pulmonary edema.


Author(s):  
Anita A. Mehta ◽  
Purav Patel ◽  
Vandana R. Thakur ◽  
Jayesh V. Beladiya

This study was designed to assess the effect of soya phosphatidylcholine (SPC) against ischemia/reperfusion (I/R) injury and the possible underlying mechanism using experimental and computational studies. I/R injury was induced by global ischemia for 30 min followed by reperfusion for 120 min. The perfusion of the SPC was performed for 10 min before inducing global ischemia. In the mechanistic study, the involvement of specific cellular pathways was identified using various inhibitors such as ATP-dependent potassium channel (KATP) inhibitor (glibenclamide), protein kinase C (PKC) inhibitor (chelerythrine), non-selective nitric oxide synthase inhibitor (L-NAME), and endothelium remover (Triton X-100). The computational study of various ligands was performed on toll-like receptor 4 (TLR4) protein using AutoDock version 4.0. SPC (100 μM) significantly decreased the levels of cardiac damage markers and %infarction compared with the vehicle control (VC). Furthermore, cardiodynamics (indices of left ventricular contraction (dp/dtmax), indices of left ventricular relaxation (dp/dtmin), coronary flow, and antioxidant enzyme levels were significantly improved as compared with VC. This protective effect was attenuated by glibenclamide, chelerythrine, and Triton X-100, but it was not attenuated by L-NAME. The computational study showed a significant bonding affinity of SPC to the TLR4-MD2 complex. Thus, SPC reduced myocardial I/R injury in isolated perfused rat hearts, which might be governed by the KATP channel, PKC, endothelium response, and TLR4-MyD88 signaling pathway.


Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Jose A Adams ◽  
Jaqueline Arias ◽  
Jorge Bassuk ◽  
Heng Wu ◽  
Arkady Uryash ◽  
...  

Periodic acceleration (pGz) is the motion of the supine body using a motorized platform (3Hz & ±0.4G). pGz produces pulsatile shear stress increasing release of endothelial derived NO (eNO) which, also decreases myocardial stunning and improves outcomes from ventricular fibrillation (VF) cardiac arrest. Preconditioning with pGz (PRE-pGz) prior to VF cardiac arrest ameliorates global post resuscitation cardiac dysfunction and reduces arrhythmias. To test whether pGz and PRE-pGz increase eNOS and phosphorylated eNOS (p-eNOS) via the PI3-kinase-Akt pathway, anesthetized, intubated male swine (40 –50lbs) were studied. Five animals had no intervention (BL) and 5 received 1 hr pGz preconditioning (pGz) followed by Western Blot of myocardial tissue. Additional animals (10 per group) received 1 hr pGz (PRE-pGz) or no treatment (CPR-CONT). In the latter groups VF was electrically induced and unsupported for 8 min followed by continuous manual chest compression and defibrillation for 10 min or until return of spontaneous circulation (ROSC). PRE-pGz animals showed less hemodynamically significant arrhythmias after ROSC than CPR-CONT (35 vs 7; p<0.05) and less myocardial stunning. eNOS and phosphorylated-eNOS (p-eNOS) significantly increased after pGz and after CPR but were significantly higher in pGz preconditioned animals along with increased phosphorylated Akt (p-Akt). The graph below shows % changes relative to BL (M±SD). *p < 0.01 PRE-pGz vs CPR-CONT. Conclusion: pGz applied prior to ischemia reperfusion injury increases eNOS and p-eNOS expression and increased p-Akt. Thus, pGz preconditioning protects myocardium during I-R in part by activating eNOS through p-Akt


Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Zhengfei Yang ◽  
Jiangang Wang ◽  
Lu Yin ◽  
Shen Zhao ◽  
Ziren Tang ◽  
...  

Introduction: Curcumin has been proven to provide potent protection of vital organs against regional ischemia reperfusion injury. In this study, we investigated the effects of curcumin on the outcomes of CPR in a rat model of cardiac arrest. Hypothesis: Curcumin reduces the severity of post-CPR myocardial dysfunction and prolong the duration of survival. Method: Sixteen male Sprague-Dawley rats weighing between 450-550g were randomized into two groups: 1) Placebo; 2) Curcumin (100 mg/kg) pre-treatment. Ventricular fibrillation (VF) was induced. After 8 mins of VF, CPR was initiated for 8 mins and defibrillation was then attempted. Myocardial function was measured by echocardiography at baseline and hourly for 4 hours following successful resuscitation. The duration of survival was observed for total 72 hours. Result: Six animals in the placebo group and seven in the curcumin group were successfully resuscitated. Post-resuscitation myocardial function was significantly impaired in all animals. However, myocardial function gradually improved 4 hours after resuscitation and was significantly better in the animals pre-treated with curcumin (Figure). Significantly shorter duration of survival of 40±29 hours was observed in the placebo group. Conclusion: In a rat model of cardiac arrest, curcuminim proves post-resuscitation myocardial dysfunction and prolongs the duration of survival.


Molecules ◽  
2019 ◽  
Vol 24 (9) ◽  
pp. 1838 ◽  
Author(s):  
Yi Zhang ◽  
Ying Zhang ◽  
Xiao-fei Jin ◽  
Xiao-hong Zhou ◽  
Xian-hui Dong ◽  
...  

Background: Ischemia/reperfusion (I/R) caused by ischemic stroke treatments leads to brain injury, and autophagy plays a role in the pathology. Astragaloside IV is a potential neuroprotectant, but its underlying mechanism on cerebral I/R injury needs to be explored. The objective of this study is to investigate the neuroprotective mechanism of Astragaloside IV against cerebral I/R injury. Methods: Middle cerebral artery occlusion method (MCAO) and oxygen and glucose deprivation/reoxygenation (OGD/R) method were used to simulate cerebral I/R injury in Sprague-Dawley (SD) rats and HT22 cells, respectively. The neurological score, 2,3,5-Triphe-nyltetrazolium chloride (TTC) staining, and transmission electron microscope were used to detect cerebral damage in SD rats. Cell viability and cytotoxicity assay were tested in vitro. Fluorescent staining and flow cytometry were applied to detect the level of apoptosis. Western blotting was conducted to examine the expression of proteins associated with autophagy. Results: This study found that Astragaloside IV could decrease the neurological score, reduce the infarct volume in the brain, and alleviate cerebral I/R injury in MCAO rats. Astragaloside IV promoted cell viability and balanced Bcl-2 and Bax expression in vitro, reduced the rate of apoptosis, decreased the expression of P62, and increased the expression of LC3II/LC3I in HT22 cells after OGD/R. Conclusions: These data suggested that Astragaloside IV plays a neuroprotective role by down-regulating apoptosis by promoting the degree of autophagy.


1999 ◽  
Vol 277 (6) ◽  
pp. H2373-H2380 ◽  
Author(s):  
Elaine J. Tanhehco ◽  
Koji Yasojima ◽  
Patrick L. McGeer ◽  
Ruth A. Washington ◽  
Kenneth S. Kilgore ◽  
...  

Both preconditioning and inhibition of complement activation have been shown to ameliorate myocardial ischemia-reperfusion injury. The recent demonstration that myocardial tissue expresses complement components led us to investigate whether preconditioning affects complement expression in the isolated heart. Hearts from New Zealand White rabbits were exposed to either two rounds of 5 min global ischemia followed by 10 min reperfusion (ischemic preconditioning) or 10 μM of the ATP-dependent K+(KATP) channel opener pinacidil for 30 min (chemical preconditioning) before induction of 30 min global ischemia followed by 60 min of reperfusion. Both ischemic and chemical preconditioning significantly ( P < 0.05) reduced myocardial C1q, C1r, C3, C8, and C9 mRNA levels. Western blot and immunohistochemistry demonstrated a similar reduction in C3 and membrane attack complex protein expression. The KATPchannel blocker glyburide (10 μM) reversed the depression of C1q, C1r, C3, C8, and C9 mRNA expression observed in the pinacidil-treated hearts. The results suggest that reduction of local tissue complement production may be one means by which preconditioning protects the ischemic myocardium.


2009 ◽  
Vol 2009 ◽  
pp. 1-7 ◽  
Author(s):  
Brad E. Zacharia ◽  
Zachary L. Hickman ◽  
Bartosz T. Grobelny ◽  
Peter A. DeRosa ◽  
Andrew F. Ducruet ◽  
...  

Out-of-hospital cardiac arrest (OHCA) is a devastating disease process with neurological injury accounting for a disproportionate amount of the morbidity and mortality following return of spontaneous circulation. A dearth of effective treatment strategies exists for global cerebral ischemia-reperfusion (GCI/R) injury following successful resuscitation from OHCA. Emerging preclinical as well as recent human clinical evidence suggests that activation of the complement cascade plays a critical role in the pathogenesis of GCI/R injury following OHCA. In addition, it is well established that complement inhibition improves outcome in both global and focal models of brain ischemia. Due to the profound impact of GCI/R injury following OHCA, and the relative lack of effective neuroprotective strategies for this pathologic process, complement inhibition provides an exciting opportunity to augment existing treatments to improve patient outcomes. To this end, this paper will explore the pathophysiology of complement-mediated GCI/R injury following OHCA.


2009 ◽  
Vol 296 (5) ◽  
pp. H1236-H1243 ◽  
Author(s):  
Anindita Das ◽  
Fadi N. Salloum ◽  
Lei Xi ◽  
Yuan J. Rao ◽  
Rakesh C. Kukreja

Sildenafil, a selective inhibitor of phosphodiesterase type 5, induces powerful protection against myocardial ischemia-reperfusion injury through activation of cGMP-dependent protein kinase (PKG). We further hypothesized that PKG-dependent activation of survival kinase ERK may play a causative role in sildenafil-induced cardioprotection via induction of endothelial nitric oxide synthase (eNOS)/inducible nitric oxide synthase (iNOS) and Bcl-2. Our results show that acute intracoronary infusion of sildenafil in Langendorff isolated mouse hearts before global ischemia-reperfusion significantly reduced myocardial infarct size (from 29.4 ± 2.4% to 15.9 ± 3.0%; P < 0.05). Cotreatment with ERK inhibitor PD98059 abrogated sildenafil-induced protection (31.8 ± 4.4%). To further evaluate the role of ERK in delayed cardioprotection, mice were treated with sildenafil (ip) 24 h before global ischemia-reperfusion. PD98059 was administered (ip) 30 min before sildenafil treatment. Infarct size was reduced from 27.6 ± 3.3% in controls to 7.1 ± 1.5% in sildenafil-treated mice ( P < 0.05). The delayed protective effect of sildenafil was also abolished by PD98059 (22.5 ± 2.3%). Western blots revealed that sildenafil significantly increased phosphorylation of ERK1/2 and GSK-3β and induced iNOS, eNOS, Bcl-2, and PKG activity in the heart 24 h after treatment. PD98059 inhibited the enhanced expression of iNOS, eNOS, and Bcl-2 and the phosphorylation of GSK-3β. PD98059 had no effect on the sildenafil-induced activation of PKG. We conclude that these studies provide first direct evidence that PKG-dependent ERK phosphorylation is indispensable for the induction of eNOS/iNOS and Bcl-2 and the resulting cardioprotection by sildenafil.


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