Pin1 aggravates renal injury induced by ischemia and reperfusion in rats via Nrf2/HO-1 mediated endoplasmic reticulum stress

Purpose: To investigate the role of peptidyl-prolyl cis/trans isomerase 1 (Pin1) on renal ischemia-reperfusion (I/R) injury and underlying mechanism. Methods: By establishing the in vitro and in vivo models of renal I/R, the role of Pin1 was explored by using molecular assays. Results: In renal I/R, endogenous Pin1 level was up-regulated in I/R-impaired kidney. Suppression of Pin1 with juglone afforded protection against I/R-mediated kidney dysfunction, and reduced I/R-induced endoplasmic reticulum (ER) stress in vivo. Consistent with the in vivo results, repression of Pin1 with juglone or gene knockdown with si-Pin1 conferred cytoprotection and restricted hypoxia/reoxygenation (H/R)-driven ER stress in HK-2 cells. Simultaneously, further study uncovered that Nrf-2/HO-1 signals was the association between Pin1 and ER stress in response to renal I/R. In addition, Nrf-2/HO-1 signal pathway was inactivated after kidney exposed to I/R, as indicated by the down-regulation of Nrf-2/HO-1 levels. Furthermore, inhibition of Pin1 remarkably rescued the inactivation ofNrf-2/HO-1. Conclusions: Pin1 modulated I/R-mediated kidney injury in ER stress manner dependent on Nrf2-HO-1 pathway in I/R injury.

Brief topical and intraluminal use of Carolina rinse solution does not attenuate experimental ischemia and reperfusion injury in rabbit jejunum / [O uso tópico breve e intraluminal da solução de Carolina rinse não atenua a injúria de isquemia e reperfusão experimental no jejuno de coelhos ]

Fifteen New Zealand adult rabbits were randomly allocated into three groups: Sham-operated (group A), Ischemia and Reperfusion (group B) and Carolina Rinse Solution (CRS) (group C). Groups B and C were subjected to one hour of ischemia and two hours of reperfusion. In group C, ten minutes before reperfusion, the bowel lumen was filled with CRS, and the segment immersed in CRS. Necrosis and loss of integrity of the villi were visible in groups B and C. Edema of the submucosa and circular muscle was observed in all groups. Hemorrhage was observed in different layers for groups B and C, but group C showed more severe hemorrhage in different layers during reperfusion. All groups showed polymorphonuclear leukocyte infiltration on the base of the mucosa, submucosa, and longitudinal muscle, in addition to polymorphonuclear leukocytes margination in the mucosal and submucosal vessels. Necrosis of enterocytes, muscles, crypts of Lieberkühn and myenteric plexus was observed in groups B and C during reperfusion. Topical and intraluminal Carolina Rinse Solution did not attenuate the effects of ischemia and reperfusion in the small intestine of rabbits.(AU)

Quinze coelhos da raça Nova Zelândia foram alocados em três grupos: instrumentado (grupo A), isquemia e reperfusão (grupo B) e solução de Carolina rinse (CRS) (grupo C). Os grupos B e C foram submetidos a uma hora de isquemia e a duas horas de reperfusão. No grupo C, 10 minutos antes da reperfusão, o segmento isolado foi imerso e teve seu lúmen preenchido com CRS. Os grupos B e C apresentaram necrose e perda progressiva da integridade das vilosidades. Foi observado edema na submucosa e na camada muscular circular em todos os grupos. Nos grupos B e C, foi observada hemorragia em diferentes camadas, mas, no grupo C, a hemorragia foi mais intensa durante a reperfusão. Todos os grupos apresentaram infiltrado de PMN na base da mucosa, na submucosa e na camada muscular longitudinal e marginação de PMN nos vasos da mucosa e da submucosa. Durante a reperfusão, foi observada necrose dos enterócitos, das camadas musculares, das criptas de Lieberkühn e do plexo mioentérico nos grupos B e C. O uso tópico e intraluminal de CRS não atenuou os efeitos da isquemia e da reperfusão no intestino delgado de coelhos.(AU)

Brief topical and intraluminal use of Carolina rinse solution does not attenuate experimental ischemia and reperfusion injury in rabbit jejunum / [O uso tópico breve e intraluminal da solução de Carolina rinse não atenua a injúria de isquemia e reperfusão experimental no jejuno de coelhos]

Fifteen New Zealand adult rabbits were randomly allocated into three groups: Sham-operated (group A), Ischemia and Reperfusion (group B) and Carolina Rinse Solution (CRS) (group C). Groups B and C were subjected to one hour of ischemia and two hours of reperfusion. In group C, ten minutes before reperfusion, the bowel lumen was filled with CRS, and the segment immersed in CRS. Necrosis and loss of integrity of the villi were visible in groups B and C. Edema of the submucosa and circular muscle was observed in all groups. Hemorrhage was observed in different layers for groups B and C, but group C showed more severe hemorrhage in different layers during reperfusion. All groups showed polymorphonuclear leukocyte infiltration on the base of the mucosa, submucosa, and longitudinal muscle, in addition to polymorphonuclear leukocytes margination in the mucosal and submucosal vessels. Necrosis of enterocytes, muscles, crypts of Lieberkühn and myenteric plexus was observed in groups B and C during reperfusion. Topical and intraluminal Carolina Rinse Solution did not attenuate the effects of ischemia and reperfusion in the small intestine of rabbits.(AU)

Quinze coelhos da raça Nova Zelândia foram alocados em três grupos: instrumentado (grupo A), isquemia e reperfusão (grupo B) e solução de Carolina rinse (CRS) (grupo C). Os grupos B e C foram submetidos a uma hora de isquemia e a duas horas de reperfusão. No grupo C, 10 minutos antes da reperfusão, o segmento isolado foi imerso e teve seu lúmen preenchido com CRS. Os grupos B e C apresentaram necrose e perda progressiva da integridade das vilosidades. Foi observado edema na submucosa e na camada muscular circular em todos os grupos. Nos grupos B e C, foi observada hemorragia em diferentes camadas, mas, no grupo C, a hemorragia foi mais intensa durante a reperfusão. Todos os grupos apresentaram infiltrado de PMN na base da mucosa, na submucosa e na camada muscular longitudinal e marginação de PMN nos vasos da mucosa e da submucosa. Durante a reperfusão, foi observada necrose dos enterócitos, das camadas musculares, das criptas de Lieberkühn e do plexo mioentérico nos grupos B e C. O uso tópico e intraluminal de CRS não atenuou os efeitos da isquemia e da reperfusão no intestino delgado de coelhos.(AU)

Resveratrol inhibits TNF-alfa-induced inflammation to protect against renal ischemia/reperfusion injury in diabetic rats

Purpose To examine effects of resveratrol on renal ischemia/ reperfusion injury (I/R) in a streptozotocin (STZ)-induced diabetic rat model. Methods Twenty-four male Sprague Dawley rats were treated with STZ injection for the development of diabetes, and divided into the following groups: Sham group, I/R group and Resveratrol group (n=8). Resveratrol (RSV) was administered at a dose of 10 mg.kg-1.d-1 fourteen days prior to suffering from I/R. Renal function, histology, SOD, MDA, TUNEL assay and expression of TNF-alfa, IL-1beta, NF-kB-P65, COX-2 and Caspase3, Bcl2 and Bax were analyzed. Results Administration of RSV significantly reduced the serum levels of renal dysfunction and injury markers, including creatinine, blood urea nitrogen and MDA; in the other hand, it significantly increased the serum levels of SOD. The protective effect of RSV was also reflected on histologic evaluation. RSV reduced the number of apoptotic cells as determined by TUNEL assay. RSV significantly reduced the protein expression of TNF-alfa, IL-1beta, NF-B-P65, COX-2 and Caspase3, and Bax. Meanwhile, RSV significantly increased the protein expression of Bcl2. Conclusion RSV attenuated I/R-induced renal injury in diabetic rats through the modulation of oxidative stress and TNF-alfa-stimulated inflammation.(AU)

Effects of bradykinin preconditioning in an experimental intestinal ischemia reperfusion model on rats

Purpose To investigate the effects of bradykinin on reperfusion injury in an experimental intestinal ischemia reperfusion model. Methods We used 32 Wistar-Albino rats. We composed 4 groups each containing 8 rats. Rats in sham group were sacrified at 100 minutes observation after laparotomy. Thirty minutes reperfusion was performed following 50 minutes ischaemia in control group after observing 20 minutes. Ischaemic preconditioning was performed in one group of the study. We performed the other study group pharmacologic preconditioning by infusional administration of 10 g/kg/minute bradykinin intravenously. We sacrified all of the rats by taking blood samples to evaluate the lactate and lactate dehydrogenase (LDH) after resection of jejunum for detecting tissue myeloperoxidase (MPO) activity. Results Lactate and LDH levels were significantly higher in control and study groups than the sham group (P 0.001). There is no difference between the study groups statistically. (P>0.05). The results were the same for MPO levels. Although definitive cell damage was determinated in the control group by hystopatological evaluation, the damage in the study groups observed was lower in different levels. However, there was no significant difference between the study groups statistically (P>0.05). Conclusion Either ischeamic preconditioning or pharmacologic preconditioning made by bradykinin reduced the ischemia reperfusion injury at jejunum.(AU)

Interventionist videothermometry: a new model of cardiac ischemia evaluation.

BACKGROUND: The purpose of the present study was to evaluate, through videothermometry, the temperature variation in the hearts of rabbits, that underwent induced myocardial ischemia and reperfusion. RESULTS: A total of 20 female rabbits were divided into two groups: a treated group and a sham group, the treatment group underwent 5 min of cardiac arrest and reperfusion, using the inflow occlusion technique. Throughout the experiment, the animals were monitored by videothermometry, observing the thermal variations of the myocardial tissue. During the experiment, at different times, blood gas tests and tests to evaluate the lactate concentrations were performed. At the end of the experiment, each heart was submitted to histopathological evaluation. In the treated group, there was a reduction in temperature of the myocardial tissue during the circulatory arrest compared to the sham group. Additionally, a colder area next to the caudal vena cava ostium and the right atrium was observed. Notably, despite the 5 min of cardiac arrest in the treated group, both the lactate and bicarbonate levels were maintained without significant variation. However, there was an increase in PaCO2 and pH reduction, featuring respiratory acidosis. In relation to the histopathological study, the presence of hydropic degeneration in the myocardium of animals in the treated group was observed. CONCLUSIONS: Based on these results, the videothermometry was efficient in identifying the range of myocardial tissue temperature, suggesting that the first areas to suffer due to cardiac arrest were the caudal vena cava ostium and the right atrium. However, in regard to the angiographic coronary thermography, the study was not feasible due to the small size of the coronary. There was no variation between the groups regarding the presence of myocardial infarction, myocardial congestion, myocardial edema and myocardial hemorrhage.

Induction of selective liver hypothermia prevents significant ischemia/reperfusion injury in Wistar rats after 24 hours

Purpose To investigate the effects of induction of selective liver hypothermia in a rodent model. Methods Seven male Wistar rats were subjected to 90 minutes of partial 70% liver ischemia and topic liver 26°C hypothermia (H group). Other seven male Wistar rats were subjected to 90 minutes of partial 70% normothermic liver ischemia (N group). Five additional rats underwent a midline incision and section of liver ligaments under normothermic conditions and without any liver ischemia (sham group). All animals were sacrificed 24-h after reperfusion, and livers were sampled for analyses. Pathology sections were scored for sinusoidal congestion, ballooning, hepatocelllular necrosis and the presence of neutrophilic infiltrates. Results At the end of the experiment, liver tissue expressions of TNF-, IL-1, iNOS and TNF-/IL-10 ratio were significantly reduced in the H group compared to N group, whereas IL-10 and eNOS were significantly increased in H group. Histopathological injury scores revealed a significant decrease in ischemia/reperfusion (I/R) injuries in H group. Conclusion Selective liver hypothermia prevented I/R injury by inhibiting the release of inflammatory cytokines, preserves microcirculation, prevents hepatocellular necrosis and leukocyte infiltration, allowing maintenance of the liver architecture.(AU)

Investigation of the role of rosmarinic acid treatment in regulating inflammation, cell damage, and angiogenesis in rat ovarian torsion and detorsion models

Purpose To investigate the protective effect of rosmarinic acid (RA) in ovarian ischemia/reperfusion injury using biochemical, histopathological, and immunohistochemical methods. Methods Wistar female rats (n = 32) were randomly divided into four groups: control, ischemia, ischemia-reperfusion, and ischemia-reperfusion with RA. Rosmarinic acid was given at a dose of 50 mg/kg by oral gavage three hours after reperfusion. Malondialdehyde (MDA) levels and glutathione peroxidase (GSH-Px) activities were determined in the ovary tissue homogenates for each rat. Results In the ischemia-reperfusion with RA group, the epithelial cells are regularly regulated at the periphery, and the degenerative changes in preantral and antral follicle cells are reduced. Follicle cells and cells in the corpus luteum showed a decrease in vascular endothelial growth factor (VEGF) expression, while VEGF demonstrated a positive reaction in vascular endothelial cells and stromal cells. The TNF-alfa expression due to the decreased degenerative effect and inflammation was positive in the macrophage cells. The expression of caspase-3 as an apoptosis change was negative in antral follicle cells and granular cells around the antral follicle. Conclusion Different doses of RA may be useful in preventing ischemic damage after vascularization, inflammation, and apoptotic development after ischemia/reperfusion.(AU)

Cardioprotective effects of pharmacological blockade of the mitochondrial calcium uniporter on myocardial ischemia-reperfusion injury

Purpose To evaluate whether the attenuation of mitochondrial Ca2+ overload produced by pharmacological blockade of mitochondrial Ca2+ uniporter (MCU) protects the myocardium against injuries caused by cardiac ischemia and reperfusion (CIR). Methods CIR was induced in adult male Wistar rats (300-350 g) by occlusion of the left anterior descendent coronary artery (10 min), followed by reperfusion (120 min). Rats were treated with different doses of MCU blocker ruthenium red (RuR), administered 5 min before ischemia or reperfusion. Results In untreated rats, the incidences of ventricular arrhythmias (VA), atrioventricular block (AVB) and the lethality (LET) induced by CIR were 85%, 79% and 70%, respectively. In rats treated with RuR before ischemia, the incidences of VA, AVB and LET were significantly reduced to 62%, 25% and 25%, respectively. In rats treated with RuR after ischemia, the incidences of VA, AVB and LET were significantly reduced to 50%, 25% and 25%, respectively. Conclusion The significant reduction of the incidence of CIR-induced VA, AVB and LET produced by the treatment with RuR indicates that the attenuation of mitochondrial Ca2+ overload produced by pharmacological blockade of MCU can protect the myocardium against injuries caused by CIR.(AU)

Remote ischemic conditioning protects against testicular ischemiareperfusion injury in rats

Purpose To evaluate the effect of remote ischemic conditioning associated to N-acetylcysteine (NAC) on testicular ischemiareperfusion (IR) injury in rats. Methods Twenty-five adult male Wistar rats were randomly distributed into five experimental groups (n=5), as follows: Sham, IR, Perconditioning (PER), NAC and PER+NAC. Two-hour ischemia was induced by rotating the left testis 720° to clockwise direction, followed by 4 hours of reperfusion. Perconditioning was performed by three I/R cycles of 10 min each on the left limb, 30 min before reperfusion. N-acetylcysteine (150 mgkg) was administered 30 min before reperfusion. Results Statistical differences were observed in MDA levels between I/R group with all groups (p 0.01), in addition there was statistical difference between PER and Sham, and PER+ NAC groups (p 0.05) in plasma. Conclusions The protective effect of perconditioning isolated in the reduction of lipid peroxidation related to oxidative stress was demonstrated. However, when Perconditioning was associated with NAC, there was no protective effect against testicular injury of ischemia and reperfusion.(AU)

Arterial thromboembolism of non-cardiogenic origin in a domestic feline with ischemia and reperfusion syndrome / Tromboembolismo arterial de origem não cardiogênica em um felino doméstico com síndrome de isquemia e reperfusão

Arterial thromboembolism (ATE) is an acute and severe clinical condition resulting from the formation of a thrombus and its accommodation in an artery, impairing the perfusion of tissues irrigated by it. In felines, it is often related to hypertrophic cardiomyopathy, but there are reports of its association with neoplasms. Ischemia and reperfusion syndrome may occur secondary to ATE and result in difficult to correct electrolyte and acid-base imbalances. The aim of the present study is to describe a case of ATE, including its clinical and laboratory findings and electrolyte and acid-base changes compatible with ischemia and reperfusion syndrome. A 14-year-old crossbreed female feline with sudden pelvic limb paralysis was treated at the Feline Medicine Service of the Federal University of Rio Grande do Sul. Clinical and laboratory alterations included hypothermia, hypotension, bradycardia, azotemia, metabolic acidosis, and hyperkalemia. The electrocardiogram indicated sinoventricular rhythm, and echocardiogram evaluation showed no alterations. Thorax radiographic evaluation revealed areas of higher radiopacity in the pulmonary fields. We opted for abdominal aorta arteriotomy as an emergency treatment for thrombus removal. The feline died in the postoperative period, and histopathological examination of lungs, mediastinal lymph nodes, and heart were performed, being compatible with pulmonary adenocarcinoma with lymph node metastasis. This study deals with a case of ATE of possible neoplastic origin, which is uncommon in cats. In this case, the patient had difficult-to-manage hemodynamic impairment, as well as electrolyte and acid-base balance disorders severe and refractory to therapy, culminating in death. The time to start treatment from the presentation of clinical signs may be determinant in therapeutic success, reducing the possible effects of reperfusion syndrome.(AU)

O tromboembolismo arterial (TEA) é uma condição clínica aguda e grave decorrente da formação de um trombo e seu alojamento em uma artéria, prejudicando a perfusão dos tecidos irrigados por ela. Em felinos, está frequentemente relacionado com a cardiomiopatia hipertrófica, porém existem relatos da sua associação com neoplasias. A síndrome de isquemia e reperfusão pode ocorrer secundária ao TEA e resultar em desequilíbrios eletrolíticos e ácido-base de difícil correção. O objetivo do presente trabalho é descrever um caso de TEA, incluindo seus achados clínico-laboratoriais e as alterações eletrolíticas e acidobásicas compatíveis com a síndrome de isquemia e reperfusão. Foi atendido no Serviço de Medicina de Felinos da Universidade Federal do Rio Grande do Sul um felino, sem raça definida (S.R.D.), fêmea, de 14 anos de idade, com paralisia súbita dos membros pélvicos. As alterações clínicas e laboratoriais incluíram hipotermia, hipotensão, bradicardia, azotemia, acidose metabólica e hipercalemia. O eletrocardiograma indicou ritmo sinoventricular e a avaliação do ecocardiograma não mostrou alterações. A avaliação radiográfica do tórax revelou áreas de maior radiopacidade nos campos pulmonares. Optou-se pela arteriotomia da aorta abdominal como tratamento emergencial para a retirada do trombo. O felino veio a óbito no pós-operatório e foi realizado exame histopatológico dos pulmões, linfonodos mediastinais e do coração, que foi compatível com adenocarcinoma pulmonar com metástase para o linfonodo. O presente trabalho trata de um caso de TEA de possível origem neoplásica, o que é pouco comum em gatos. Neste caso, o paciente apresentou comprometimento hemodinâmico de difícil manejo, além de desordens eletrolíticas e do equilíbrio ácido-base graves e refratárias a terapia, culminando em óbito. O tempo do início do tratamento a partir da apresentação dos sinais clínicos pode ser determinante no sucesso terapêutico, reduzindo os...(AU)

Arterial thromboembolism of non-cardiogenic origin in a domestic feline with ischemia and reperfusion syndrome / Tromboembolismo arterial de origem não cardiogênica em um felino doméstico com síndrome de isquemia e reperfusão

Arterial thromboembolism (ATE) is an acute and severe clinical condition resulting from the formation of a thrombus and its accommodation in an artery, impairing the perfusion of tissues irrigated by it. In felines, it is often related to hypertrophic cardiomyopathy, but there are reports of its association with neoplasms. Ischemia and reperfusion syndrome may occur secondary to ATE and result in difficult to correct electrolyte and acid-base imbalances. The aim of the present study is to describe a case of ATE, including its clinical and laboratory findings and electrolyte and acid-base changes compatible with ischemia and reperfusion syndrome. A 14-year-old crossbreed female feline with sudden pelvic limb paralysis was treated at the Feline Medicine Service of the Federal University of Rio Grande do Sul. Clinical and laboratory alterations included hypothermia, hypotension, bradycardia, azotemia, metabolic acidosis, and hyperkalemia. The electrocardiogram indicated sinoventricular rhythm, and echocardiogram evaluation showed no alterations. Thorax radiographic evaluation revealed areas of higher radiopacity in the pulmonary fields. We opted for abdominal aorta arteriotomy as an emergency treatment for thrombus removal. The feline died in the postoperative period, and histopathological examination of lungs, mediastinal lymph nodes, and heart were performed, being compatible with pulmonary adenocarcinoma with lymph node metastasis. This study deals with a case of ATE of possible neoplastic origin, which is uncommon in cats. In this case, the patient had difficult-to-manage hemodynamic impairment, as well as electrolyte and acid-base balance disorders severe and refractory to therapy, culminating in death. The time to start treatment from the presentation of clinical signs may be determinant in therapeutic success, reducing the possible effects of reperfusion syndrome.

O tromboembolismo arterial (TEA) é uma condição clínica aguda e grave decorrente da formação de um trombo e seu alojamento em uma artéria, prejudicando a perfusão dos tecidos irrigados por ela. Em felinos, está frequentemente relacionado com a cardiomiopatia hipertrófica, porém existem relatos da sua associação com neoplasias. A síndrome de isquemia e reperfusão pode ocorrer secundária ao TEA e resultar em desequilíbrios eletrolíticos e ácido-base de difícil correção. O objetivo do presente trabalho é descrever um caso de TEA, incluindo seus achados clínico-laboratoriais e as alterações eletrolíticas e acidobásicas compatíveis com a síndrome de isquemia e reperfusão. Foi atendido no Serviço de Medicina de Felinos da Universidade Federal do Rio Grande do Sul um felino, sem raça definida (S.R.D.), fêmea, de 14 anos de idade, com paralisia súbita dos membros pélvicos. As alterações clínicas e laboratoriais incluíram hipotermia, hipotensão, bradicardia, azotemia, acidose metabólica e hipercalemia. O eletrocardiograma indicou ritmo sinoventricular e a avaliação do ecocardiograma não mostrou alterações. A avaliação radiográfica do tórax revelou áreas de maior radiopacidade nos campos pulmonares. Optou-se pela arteriotomia da aorta abdominal como tratamento emergencial para a retirada do trombo. O felino veio a óbito no pós-operatório e foi realizado exame histopatológico dos pulmões, linfonodos mediastinais e do coração, que foi compatível com adenocarcinoma pulmonar com metástase para o linfonodo. O presente trabalho trata de um caso de TEA de possível origem neoplásica, o que é pouco comum em gatos. Neste caso, o paciente apresentou comprometimento hemodinâmico de difícil manejo, além de desordens eletrolíticas e do equilíbrio ácido-base graves e refratárias a terapia, culminando em óbito. O tempo do início do tratamento a partir da apresentação dos sinais clínicos pode ser determinante no sucesso terapêutico, reduzindo os...

Expression analysis of long non-coding RNAs in a renal ischemia-reperfusion injury model

Purpose: To investigate the long non-coding RNAs (lncRNAs) profile on renal ischemia reperfusion in a mouse model. Methods: Microarray analysis was used to study the expression of misregulated lncRNA in a mouse model of renal ischemia reperfusion (I/R) with long ischemia time. Quantitative real-time PCR (qPCR) was used to verify the expression of selected lncRNAs and mRNAs. The potential functions of the lncRNA was analyzed by bioinformatics tools and databases. Results: Kidney function was impaired in I/R group compared to the normal group. Analysis showed that a total of 2267 lncRNAs and 2341 messenger RNAs (mRNAs) were significantly expressed in I/R group (≥2.0-fold, p < 0.05). The qPCR result showed that lncRNAs and mRNAs expression were consistent with the microarray analysis. The co-expression network profile analysis based on five validated lncRNAs and 203 interacted mRNAs showed it existed a total of 208 nodes and 333 connections. The GO and KEEG pathway analysis results showed that multiple lncRNAs are involved the mechanism of I/R. Conclusion: Multiple lncRNAs are involved in the mechanism of I/R. These analysis results will help us to further understand the mechanism of I/R and promote the new methods targeted at lncRNA to improve I/R injury.(AU)

Evaluation of the therapeutic effect of methylene blue on the liver of rats submitted to ischemia and reperfusion

Purpose:To analyze the effect of methylene blue (MB) therapy during the liver ischemia-reperfusion injury (I/R) process.Methods:Thirty-five male Wistar rats were used, (70%) submitted to partial ischemia (IR) or not (NIR) (30%) were obtained from the same animal. These animals were divided into six groups: 1) Sham (SH), 2) Sham with MB (SH-MB); 3) I/R, submitted to 60 minutes of partial ischemia and 15 minutes of reperfusion; 4) NI/R, without I/R obtained from the same animal of group I/R; 5) I/R-MB submitted to I/R and MB and 6) NI/R-MB, without I/R. Mitochondrial function was evaluated. Osmotic swelling of mitochondria as well as the determination of malondialdehyde (MDA) was evaluated. Serum (ALT/AST) dosages were also performed. MB was used at the concentration of 15mg/kg, 15 minutes before hepatic reperfusion. Statistical analysis was done by the Mann Whitney test at 5%.Results:State 3 shows inhibition in all ischemic groups. State 4 was increased in all groups, except the I/R-MB and NI/R-MB groups. RCR showed a decrease in all I/R and NI/R groups. Mitochondrial osmotic swelling showed an increase in all I/R NI/R groups in the presence or absence of MB. About MDA, there was a decrease in SH values in the presence of MB and this decrease was maintained in the I/R group. AST levels were increased in all ischemic with or without MB.Conclusions:The methylene blue was not able to restore the mitochondrial parameters studied. Also, it was able to decrease lipid peroxidation, preventing the formation of reactive oxygen species.(AU)

The role of ischemic preconditioning in gene expression related to inflammation in a rat model of intestinal ischemia-reperfusion injury

Purpose:To investigate the gene expression related to inflammation on mice subjected to intestinal ischemia and reperfusion (I/R) and treated with ischemic preconditioning (IPC).Methods:Thirty rats (EPM-Wistar), distributed in five groups of six animals each, were underwent anesthesia and laparotomy. The ischemia time was standardized in 60 minutes and the reperfusion time 120 minutes. IPC was standardized in 5 minutes of ischemia followed by 10 minutes of reperfusion accomplished before I/R. The control group was submitted only to anesthesia and laparotomy. The other groups were submitted to ischemia, I/R, ischemia + IPC and I/R + IPC. It was collected a small intestine sample to analyses by Quantitative Polymerase Chain Reaction in real Time (RT-qPCR) and histological analyses. It was studied 27 genes.Results:The groups that received IPC presented downregulation of genes, observed in of genes in IPC+ischemia group and IPC+I/R group. Data analysis by clusters showed upregulation in I/R group, however in IPC groups occurred downregulation of genes related to inflammation.Conclusion:The ischemia/reperfusion promoted upregulation of genes related to inflammation, while ischemic preconditioning promoted downregulation of these genes.(AU)

Adipose tissue derived mesenchymal stem cell transplantation in the treatment of ischemia/reperfusion induced acute kidney injury in rats. Application route and therapeutic window

Purpose:To evaluate renal repair in rats who had renal infarction induced by the obstruction of blood flow in the renal artery and were treated with transplantation of adipose tissue derived mesenchymal stem cellMethods:16-week-old Wistar rats (n=72) were used, submitted to celiotomy and had of the renal artery and vein clipped for 24 hours. The animals were randomly assigned to 10 experimental homogeneous groups, corresponding to the treatments with phosphate-buffered saline (PBS) or adipose tissue derived mesenchymal stem cell (ADSC), duration of application (24 or 48 hours), and site of transplantation (lateral vein of the tail or intrarenal). After the treatments were performed, at 8 and 31 days, four animals in each group were subjected to left nephrectomy for histological studies.Results:Histologically, a higher amount of cell debris and tubules devoid of the epithelium and a higher degree of necrosis were observed in the groups treated with PBS, as opposed to a low degree of necrosis and higher tubular vascularization in the groups treated with ADSC, particularly in the group treated with intrarenal ADSC 48 hours after injury.Conclusion:The transplantation of ADSC positively contributed to the replacement of necrotic tissue by renal tubular cells, vascularization of the renal parenchyma, and restoration of the organ function.(AU)

The role of the exogenous supply of adenosine triphosphate in the expression of Bax and Bcl2L1 genes in intestinal ischemia and reperfusion in rats

Purpose: To investigate the role of the exogenous supply of adenosine triphosphate (ATP) in the expression of Bax and Bcl2L1 genes in intestinal ischemia and reperfusion (IR) in rats. Methods: The study was designed as a randomized controlled trial with a blinded assessment of the outcome. Eighteen adult male Wistar-EPM1 rats were housed under controlled temperature and light conditions (22-23°C, 12 h light/dark cycle). The animals were randomly divided into 3 groups: 1. Sham group (SG): no clamping of the superior mesenteric artery; 2. Ischemia and reperfusion group (IRG): 3. Ischemia and reperfusion plus ATP (IRG + ATP). ATP was injected in the femoral vein before and after ischemia. Afterwards, intestinal segments were appropriately removed and processed for Endothelial Cell Biology Rat RT2 Profiler PCR Array. Results: ATP promoted the upregulation of Bcl2L1 gene expression, whereas it did not have significant effects on Bax gene expression. In addition, the relation of Bax/Bcl2L1 gene expression in the IRG group was 1.39, whereas it was 0.43 in the IRG + ATP group. Bcl2L1 plays a crucial role in protecting against intestinal apoptosis after ischemia and reperfusion. Increased Bcl2L1 expression can inhibit apoptosis while decreased Bcl2L1 expression can trigger apoptosis. Conclusion: Adenosine triphosphate was associated with antiapoptotic effects on the rat intestine ischemia and reperfusion by upregulating of Bcl2L1 gene expression.(AU)

Topical hepatic hypothermia associated with ischemic preconditioning. Histopathological and biochemical analysis of ischemia reperfusion damage in a 24 hour model

Purpose: To develop a new 24 hour extended liver ischemia and reperfusion (LIR) model analyzing the late biochemical and histopathological results of the isolated and combined application of recognized hepatoprotective mechanisms. In addition, we used a new stratification with zoning to classify the histological lesion. Methods: A modified animal model of severe hepatic damage produced through 90 minutes of segmental ischemia (70% of the organ) and posterior observation for 24 hours of reperfusion, submitted to ischemic preconditioning (IPC) and topical hypothermia (TH) at 26ºC, in isolation or in combination, during the procedure. Data from intraoperative biometric parameters, besides of late biochemical markers and histopathological findings, both at 24 hours evolution time, were compared with control (C) and normothermic ischemia (NI) groups. Results: All groups were homogeneous with respect to intraoperative physiological parameters. There were no losses once the model was stablished. Animals subjected to NI and IPC had worse biochemical (gamma-glutamyl transpeptidase, alkaline phosphatase, lactate dehydrogenase, aspartate aminotransferase, alanine aminotransferase, direct bilirubin, and total bilirubin) and histopathological scores (modified Suzuki score) compared to those of control groups and groups with isolated or associated TH (p 0.05). Conclusion: The new extended model demonstrates liver ischemia and reperfusion at 24 hour of evolution and, in this extreme scenario, only the groups subjected to topical hypothermia, combined with ischemic preconditioning or alone, had better outcomes than those subjected to only ischemic preconditioning and normothermic ischemia, reaching similar biochemical and histopathological scores to those of the control group.(AU)

The effects of local ischemic preconditioning and topical hypothermia in renal ischemia/reperfusion injury in rats

Purpose: Topical hypothermia and local ischemic preconditioning have been shown to reduce renal ischemia-reperfusion (I/R) injury individually. We examined whether combination of both strategies lessens renal I/R injury. Methods: Post right nephrectomy, 40 male Wistar rats were randomly assigned to five experimental protocols performed in the left kidney: topical hypothermia without ischemia (TH), warm ischemia (IR), ischemic preconditioning followed by warm ischemia (IPC+IR), cold ischemia (TH+IR), and ischemic preconditioning followed by cold ischemia (IPC+TH+IR). Eight randomly assigned right kidneys constituted the control group. After 240 min of reperfusion, the left kidney was retrieved to evaluate histological changes, lipid peroxidation and antioxidant enzymes activity. Serum was collected to evaluate urea and creatinine. Results: IPC+TH+IR group revealed no difference to any other group subjected to ischemia in relation to histological changes, lipid peroxidation and antioxidant enzymes activity. Creatinine was lower in IPC+TH+IR group compared with IPC+IR, but showed no difference compared to TH+IR group. Conclusions: Combination of local ischemic preconditioning (IPC) and topical hypothermia conferred no protection in renal I/R injury. Moreover, local IPC solely followed by warm ischemia impaired renal function more than warm ischemia alone.(AU)

Protective effect of intraportal infusion of hypothermic hydrogen-rich saline solution on hepatic warm ischemia/reperfusion injury in rat model

The aim of the present study was to investigate the effects of intraportal administration of hypothermic hydrogenrich saline solution (HRSS) on hepatic ischemia/reperfusion (I/R) injury. Thirty rats were divided equally into six groups; 1) sham, no I/R or transfusion, 2) I/R injury (60 minutes ischemia + 120 minutes reperfusion, 3) I/R injury + normal saline 24C, 4) I/R injury + normal saline 4C, 5) I/R injury + HRSS 24C, 6) I/R injury + HRSS 4C. In groups 3-6, 1 mg/kg normal saline (NS) and/or HRSS were administered into the vein of the left lateral and median lobes of the liver (upper the site of clumping) 10 minutes before finishing of ischemic period. The harvest time points were at 2 hours post reperfusion in all groups. Cell death, sinusoidal dilatation, congestion, hemorrhage, and neutrophil infiltration were observed in I/R group, while these histopathological changes were attenuated in the hypothermic HRSS administrated groups (P < 0.01). The level of alanine aminotransferase, aspartate aminotransferase, malondialdehyde, interleukin 6, tumor necrosis factor a, and caspase-3 were increased significantly by I/R injury and hypothermic HRSS administration reduced all these markers (P < 0.01). SOD level was low in I/R group whereas it tended to increase in the hypothermic HRSS administrated groups (P < 0.01). The present study demonstrated that hypothermic hydrogen-rich saline solution effectively protected the hepatic tissue against cellular injury and organ dysfunction through the mechanisms that decrease the effect of oxidative stress, inflammation, apoptosis and necrosis.