RESUMO
Gastrointestinal ischemia/reperfusion (I/R) generates pathological alterations that could lead to death. Early ischemic damage markers could be used to guide therapy and improve outcomes. AIM: To relate hypoxia-inducible factor 1α (HIF-1α) activation and inducible nitric oxide synthase (iNOS) expression to gastric impedance changes due to I/R damage. METHODS: Experimental animals were randomly distributed into 3 groups: control, ischemia (30 min) and I/R (60 min). Gastric ischemia was generated by celiac artery clamping for 30 min, and then blood flow was restored for 60 min. Impedance spectra and biopsies of the glandular portion were obtained for histological and immunohistochemical analyses. Immunodetection of both HIF-1α and iNOS was performed. RESULTS: Under ischemia and I/R conditions, there was an increase (p<0.05) in the impedance parameters. Histologically, under ischemic conditions, edema and necrosis were observed in epithelium and significant vascular congestion. In I/R condition, alterations of the glandular and luminal integrity were found, which generated areas of epithelial erosion. Immunohistochemical analysis of HIF-1α revealed an increase (p<0.01) in the number of immunoreactive cells in the ischemia (35.7±13.9) and I/R (119.9±18.8) conditions compared to the control (0.8±1.2). Immunodetection of iNOS showed an increase (p<0.01) in the number of cells expressing iNOS under the ischemia (5.4±2.9) and I/R conditions (27.4±11.3) was observed compared to the control (0.4±0.8). CONCLUSION: Early changes in impedance in response to I/R is related to histopathological changes, the nuclear stabilization and translocation of HIF-1α as well as expression of iNOS.
Assuntos
Mucosa Gástrica/enzimologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Imuno-Histoquímica , Óxido Nítrico Sintase Tipo II/metabolismo , Traumatismo por Reperfusão/enzimologia , Gastropatias/enzimologia , Transporte Ativo do Núcleo Celular , Animais , Biópsia , Modelos Animais de Doenças , Edema/enzimologia , Edema/patologia , Impedância Elétrica , Mucosa Gástrica/patologia , Masculino , Necrose , Estabilidade Proteica , Ratos Wistar , Traumatismo por Reperfusão/patologia , Gastropatias/patologia , Fatores de TempoRESUMO
The production of nitric oxide (NO) by nitric oxide synthases (NOS) depends on the bioavailability of L-arginine as NOS competes with arginase for this common substrate. As arginase activity increases, less NO is produced and adverse cardiovascular consequences can emerge. (-)-Epicatechin (EPI), the most abundant flavonoid in cacao, has been reported to stimulate endothelial and neuronal NOS expression and function leading to enhanced vascular function and cardioprotective effects. However, little is known about the effects of EPI on myocardial arginase activity. The aim of the present study was to determine if EPI is able to interact and modulate myocardial arginase and NOS expression and activity. For this purpose, in silico modeling, in vitro activity assays and a rat model of ischemia/reperfusion injury were used. In silico and in vitro results demonstrate that EPI can interact with arginase and significantly decrease its activity. In vivo, 10 days of EPI pretreatment reduces ischemic myocardium arginase expression while increasing NOS expression and phosphorylation levels. Altogether, these results may partially account for the cardioprotective effects of EPI.
Assuntos
Arginase/antagonistas & inibidores , Cardiotônicos/farmacologia , Catequina/farmacologia , Inibidores Enzimáticos/farmacologia , Traumatismo por Reperfusão/enzimologia , Traumatismo por Reperfusão/prevenção & controle , Animais , Arginase/química , Arginase/metabolismo , Catequina/metabolismo , Modelos Animais de Doenças , Inibidores Enzimáticos/metabolismo , Simulação de Acoplamento Molecular , Miocárdio/enzimologia , Óxido Nítrico Sintase/metabolismo , Conformação ProteicaRESUMO
Inflammation plays an important role in cerebral ischemia reperfusion, which can cause severe damage to the brain and may lead to cerebral hemorrhage transformation. p38-mitogen-activated protein kinase (p38mapk) has been implicated in the etiology of a number of diseases because it is a cause of inflammation, but comparatively little research has been carried out into its role in the etiology of ischemia reperfusion. We investigated the expression of p38mapk in cerebral ischemia reperfusion to gain a better understanding of its potential role in hemorrhagic transformation (HT). One hundred rats were randomly divided into three groups: an ischemia reperfusion group, an ischemia group, and a sham-operated group. We carried out neurological deficit assessments, infarct volume measurements, histopathological examinations, and immunohistochemistry analyses. p38mapk was overexpressed in the ischemia reperfusion group, which exhibited severe tissue damage and greater edema than the other two groups. These results suggest that p38mapk plays an important role in cerebral ischemia reperfusion, and may be one of the causes of HT.
Assuntos
Isquemia Encefálica/enzimologia , Encéfalo/enzimologia , Traumatismo por Reperfusão/enzimologia , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Animais , Encéfalo/patologia , Encéfalo/fisiopatologia , Encéfalo/cirurgia , Isquemia Encefálica/fisiopatologia , Isquemia Encefálica/cirurgia , Contagem de Células , Ativação Enzimática , Masculino , Necrose , Ratos Sprague-Dawley , Traumatismo por Reperfusão/fisiopatologia , Traumatismo por Reperfusão/cirurgiaRESUMO
Acute brain ischemia can induce the activation of c-Jun N-terminal kinases (JNKs). Hypertension is a critical etiology for brain ischemia. We identified the effects of hypertension on the activation of JNK as well as its impact on SP600125, a JNK inhibitor, during endoplasmic reticulum stress (ERS) in the hippocampus using a rat model. Transient whole-brain ischemia was induced by 4-vessel occlusion (bilateral vertebral and bilateral common carotid arteries) in normal and spontaneous hypertensive rats. SP600125 (0.05 mg/kg, iv) was administered 30 min before ischemia. Morphological changes in hippocampal nerve cells were observed by cresyl violet staining. Phosphorylation of JNK, and expression levels of CHOP and GPR78, markers for ERS, were detected by western blot at 1, 6, 24, and 48 h, and neurological outcomes were measured using an eight-arm radial maze 48 h after ischemia. Hypertension apparently aggravated impairment of memory function, decreased the density of surviving neurons, increased phosphorylation of JNK, and enhanced CHOP expression, but reduced GPR78 levels in hippocampal tissues following brain ischemia. SP600125 alleviated neurological dysfunction, improved neuron survival, decreased phosphorylation of JNK and levels of CHOP, but increased expression of GPR78 in rats with hypertension during cerebral ischemia by inhibition of ERS.
Assuntos
Isquemia Encefálica/enzimologia , Estresse do Retículo Endoplasmático/fisiologia , Hipocampo/irrigação sanguínea , Hipertensão/enzimologia , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Sistema de Sinalização das MAP Quinases , Animais , Antracenos , Isquemia Encefálica/fisiopatologia , Região CA1 Hipocampal/citologia , Região CA1 Hipocampal/efeitos dos fármacos , Modelos Animais de Doenças , Ativação Enzimática , Proteínas de Choque Térmico/efeitos dos fármacos , Hipocampo/enzimologia , Hipocampo/fisiopatologia , Hipertensão/fisiopatologia , Masculino , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Traumatismo por Reperfusão/enzimologia , Traumatismo por Reperfusão/fisiopatologia , Fator de Transcrição CHOP/metabolismoRESUMO
Objetivo. Analizar la percepción de mujeres y proveedores de salud sobre cuándo y cómo realizar acciones para la detección temprana del cáncer de mama y cervicouterino en localidades de Morelos con presencia de población indígena. Material y métodos. Se entrevistó a 10 proveedores de salud y 58 usuarias en unidades médicas del primer nivel de atención de cinco localidades; luego se analizó la información con base en el paradigma de la teoría fundamentada. Resultados. El personal de salud está deficientemente familiarizado con los lineamientos oficiales para la detección de cáncer cervicouterino y de mama. Pocos practican sus labores bajo una perspectiva de sensibilización intercultural. Las usuarias tienen nociones imprecisas o equivocadas de las acciones de detección. Conclusiones. La necesidad de capacitación con apego a las normas es evidente. Urge asumir un abordaje con pertinencia cultural que permita la comunicación eficiente y alfabetización en salud para la detección oportuna de estos dos cánceres.
Objective. To analyze the perception in relation to when and how to perform actions for the early detection of breast and cervical cancer among women and health care providers in communities with a high percentage of indigenous population in Morelos, Mexico. Materials and methods. Ten health providers and 58 women users of health services were interviewed which have a first level of attention in five communities. The analysis was developed under the approach of the Grounded Theory. Results. Providers are poorly informed about current regulations and specific clinical indications for the detection of cervical and breast cancer. Few propitiate health literacy under intercultural sensitization. The users have imprecise or wrong notions of the early detection. Conclusions. The need for training in adherence to norms is evident. It is urgent to assume a culturally relevant approach to enable efficient communication and promote health literacy for early detection of these two cancers.
Assuntos
Animais , Masculino , Coelhos , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Traumatismo por Reperfusão/metabolismo , Compostos de Tungstênio/farmacologia , Xantina Oxidase/antagonistas & inibidores , Administração Oral , Alanina Transaminase/sangue , Líquido da Lavagem Broncoalveolar/química , Fígado/metabolismo , Traumatismo por Reperfusão/enzimologia , Compostos de Tungstênio/administração & dosagem , Xantina Oxidase/sangue , Xantina Oxidase/fisiologiaRESUMO
The aim of this study was to analyze the effects of cryotherapy on the biochemical and morphological changes in ischemic and reperfused (I/R) gastrocnemius muscle of rats. Forty male Wistar rats were divided into control and I/R groups, and divided based on whether or not the rats were submitted to cryotherapy. Following the reperfusion period, biochemical and morphological analyses were performed. Following cryotherapy, a reduction in thiobarbituric acid-reactive substances and dichlorofluorescein oxidation levels were observed in I/R muscle. Cryotherapy in I/R muscle also minimized effects such as decreased cellular viability, levels of non-protein thiols and calcium ATPase activity as well as increased catalase activity. Cryotherapy also limited mitochondrial dysfunction and decreased the presence of neutrophils in I/R muscle, an effect that was corroborated by reduced myeloperoxidase activity in I/R muscle treated with cryotherapy. The effects of cryotherapy are associated with a reduction in the intensity of the inflammatory response and also with a decrease in mitochondrial dysfunction.
Assuntos
Crioterapia , Isquemia/terapia , Músculo Esquelético/irrigação sanguínea , Traumatismo por Reperfusão/terapia , Análise de Variância , Animais , Biomarcadores/metabolismo , Sobrevivência Celular/fisiologia , Modelos Animais de Doenças , Isquemia/enzimologia , Isquemia/fisiopatologia , Masculino , Mitocôndrias Musculares/enzimologia , Músculo Esquelético/enzimologia , Estresse Oxidativo/fisiologia , Peroxidase/metabolismo , Ratos , Ratos Wistar , Traumatismo por Reperfusão/enzimologia , Traumatismo por Reperfusão/fisiopatologiaRESUMO
Accumulating evidence indicates that resveratrol potently protects against cerebral ischemia damage due to its oxygen free radicals scavenging and antioxidant properties. However, cellular mechanisms that may underlie the neuroprotective effects of resveratrol in brain ischemia are not fully understood yet. This study aimed to investigate the potential association between the neuroprotective effect of resveratrol and the apoptosis/survival signaling pathways, in particular the glycogen synthase kinase 3 (GSK-3ß) and cAMP response element-binding protein (CREB) through phosphatidylinositol 3-kinase (PI3-K)-dependent pathway. An experimental model of global cerebral ischemia was induced in rats by the four-vessel occlusion method for 10 min and followed by different periods of reperfusion. Nissl staining indicated extensive neuronal death at 7 days after ischemia/reperfusion. Administration of resveratrol by i.p. injections (30 mg/kg) for 7 days before ischemia significantly attenuated neuronal death. Both GSK-3ß and CREB appear to play a critical role in resveratrol neuroprotection through the PI3-K/Akt pathway, as resveratrol pretreatment increased the phosphorylation of Akt, GSK-3ß and CREB in 1 h in the CA1 hippocampus after ischemia/reperfusion. Furthermore, administration of LY294002, an inhibitor of PI3-K, compromised the neuroprotective effect of resveratrol and decreased the level of p-Akt, p-GSK-3ß and p-CREB after ischemic injury. Taken together, the results suggest that resveratrol protects against delayed neuronal death in the hippocampal CA1 by maintaining the pro-survival states of Akt, GSK-3ß and CREB pathways. These data suggest that the neuroprotective effect of resveratrol may be mediated through activation of the PI3-K/Akt signaling pathway, subsequently downregulating expression of GSK-3ß and CREB, thereby leading to prevention of neuronal death after brain ischemia in rats.
Assuntos
Isquemia Encefálica/metabolismo , Região CA1 Hipocampal/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Traumatismo por Reperfusão/tratamento farmacológico , Transdução de Sinais/efeitos dos fármacos , Estilbenos/farmacologia , Animais , Apoptose/efeitos dos fármacos , Isquemia Encefálica/tratamento farmacológico , Isquemia Encefálica/enzimologia , Região CA1 Hipocampal/enzimologia , Região CA1 Hipocampal/metabolismo , Cromonas/farmacologia , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Quinase 3 da Glicogênio Sintase/metabolismo , Glicogênio Sintase Quinase 3 beta , Masculino , Morfolinas/farmacologia , Neurônios/enzimologia , Neurônios/metabolismo , Fármacos Neuroprotetores/uso terapêutico , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase , Fosforilação , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Ratos Wistar , Traumatismo por Reperfusão/enzimologia , Traumatismo por Reperfusão/metabolismo , Resveratrol , Estilbenos/uso terapêuticoRESUMO
OBJECTIVES: We tested the effects of liver reperfusion in the immunohistochemical expression of nitric oxide synthase on the thoracic aorta and the heart. MATERIALS AND METHODS: We randomized 24 male Wistar rats into 3 groups: (1) control; (2) R2 group, with 60 minutes of partial (70%) liver ischemia and 2 hours of global liver reperfusion; (3) and R6 group, with 60 minutes of partial liver ischemia and 6 hours of global liver reperfusion. RESULTS: In the heart, there was little, diffuse immunohistochemical endothelial staining; immunohistochemical inducible nitric oxide synthase staining was expressed in the adventitia layer of intramyocardial vessels in both cases, with a time-dependent but not statistically significant increase. In the thoracic aorta, a time-dependent decrease in endothelial nitric oxide synthase expression in the muscular layer after reperfusion, which was statistically significant in R6 versus the control. Positive immunostaining for inducible nitric oxide synthase was seen in the muscular and endothelial layers, and this varied from moderate in the control group, to light in the endothelium in groups R2 and R6. CONCLUSIONS: We observed changes that may be implicated in heart injury and impairment of aortal tone after liver ischemia and reperfusion injury.
Assuntos
Aorta Torácica/enzimologia , Fígado/irrigação sanguínea , Miocárdio/enzimologia , Óxido Nítrico Sintase/metabolismo , Traumatismo por Reperfusão/enzimologia , Alanina Transaminase/metabolismo , Animais , Aorta Torácica/patologia , Aspartato Aminotransferases/metabolismo , Fígado/enzimologia , Fígado/patologia , Masculino , Malondialdeído/metabolismo , Modelos Animais , Miocárdio/patologia , Ratos , Ratos Wistar , Traumatismo por Reperfusão/patologia , Fatores de TempoRESUMO
PURPOSE: To determine the effects of oral L-glutamine (L-Gln) and the dipeptide L-alanyl-glutamine (L-Ala-Gln) upon the activity of the malate-aspartate shuttle in the rat distal small intestine following ischemia and reperfusion. METHODS: Seventy-two Wistar rats (350-400g), were randomized in 2 groups (n = 36): group S (Sham) and Group T (Treatment) and divided into 12 subgroups (n = 6): A-A6, and B1-B6. The subgroups A1-A3 were subjected to sham procedures at 30 and 60 minutes. Thirty minutes before the study, rats were treated with calcium caseinate, 0.5g/Kg (subgroups A1, A4, B1, B4), L-Gln, 0.5g / kg (subgroups A2, A5, B2 and B5) or L-Ala-Gln, 0.75g/Kg (subgroups A3, A6, B3, B6), administered by gavage. Ischemia was achieved by clamping the mesenteric vessels, delimiting a segment of bowel 5 cm long and 5 cm apart from the ileocecal valve. Samples were collected 30 and 60 minutes after start of the study for real-time PCR assay of malate dehydrogenases (MDH1-2) and aspartate-aminotransferases (GOT1-2) enzymes. RESULTS: Tissue MDH and GOT mRNA expression in intestinal samples from rats preconditioned with either L-Gln or L-Ala-Gln showed no significant differences both during ischemia and early reperfusion. CONCLUSION: Activation of the malate-aspartate shuttle system appears not to be the mechanism of glutamine-mediated elevation of glucose oxidation in rat intestine during ischemia/reperfusion injury.
Assuntos
Ácido Aspártico/metabolismo , Glutamina/farmacologia , Intestino Delgado/irrigação sanguínea , Malatos/metabolismo , RNA Mensageiro/sangue , Traumatismo por Reperfusão/prevenção & controle , Animais , Aspartato Aminotransferases/sangue , Aspartato Aminotransferases/genética , Dipeptídeos/farmacologia , Modelos Animais de Doenças , Intestino Delgado/enzimologia , Malato Desidrogenase/sangue , Malato Desidrogenase/genética , Distribuição Aleatória , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase em Tempo Real , Traumatismo por Reperfusão/enzimologia , Fatores de TempoRESUMO
PURPOSE: To determine the effects of oral L-glutamine (L-Gln) and the dipeptide l-alanyl-glutamine (L-Ala-Gln) upon the activity of the malate-aspartate shuttle in the rat distal small intestine following ischemia and reperfusion. METHODS: Seventy-two Wistar rats (350-400g), were randomized in 2 groups (n = 36): group S (Sham) and Group T (Treatment) and divided into 12 subgroups (n = 6): A-A6, and B1-B6. The subgroups A1-A3 were subjected to sham procedures at 30 and 60 minutes. Thirty minutes before the study, rats were treated with calcium caseinate, 0.5g/Kg (subgroups A1, A4, B1, B4), L-Gln, 0.5g / kg (subgroups A2, A5, B2 and B5) or L-Ala-Gln, 0.75g/Kg (subgroups A3, A6, B3, B6), administered by gavage. Ischemia was achieved by clamping the mesenteric vessels, delimiting a segment of bowel 5 cm long and 5 cm apart from the ileocecal valve. Samples were collected 30 and 60 minutes after start of the study for real-time PCR assay of malate dehydrogenases (MDH1-2) and aspartate-aminotransferases (GOT1-2) enzymes. RESULTS: Tissue MDH and GOT mRNA expression in intestinal samples from rats preconditioned with either L-Gln or L-Ala-Gln showed no significant differences both during ischemia and early reperfusion. CONCLUSION: Activation of the malate-aspartate shuttle system appears not to be the mechanism of glutamine-mediated elevation of glucose oxidation in rat intestine during ischemia/reperfusion injury.
OBJETIVO: Determinar os efeitos da administração oral de L-glutamina (L-Gln) e do dipeptídeo L-alanil-glutamina (L-Ala-Gln) sobre a atividade do ciclo malato-aspartato no intestino delgado distal de ratos após isquemia/reperfusão. MÉTODOS: Setenta e dois ratos Wistar (350-400g) foram randomizados em 2 grupos (n = 36): T grupo S (Sham) e grupo (Tratamento) e distribuídos em 12 subgrupos (n = 6): A-A6, e B1-B6. Os subgrupos A1-A3 foram submetidos a procedimentos "sham" aos 30 e 60 minutos. Trinta minutos antes do estudo, os ratos foram tratados com caseinato de cálcio, 0,5 g/kg (subgrupos A1, A4, B1 e B4), L-Gln, 0,5 g/kg (subgrupos A2, A5, B2 e B5) ou L-Ala -Gln, 0,75g/kg (subgrupos A3, A6, B3, B6), administrado por gavagem. A isquemia foi obtida por pinçamento dos vasos mesentéricos, delimitando um segmento do intestino cinco centímetros de comprimento e 5 cm da válvula ileocecal. Amostras foram coletadas aos 30-60 minutos para ensaio de PCR em tempo real das enzimas malato desidrogenases (MDH1-2), aspartato-aminotransferase (GOT1-2). RESULTADOS: A expressão de MDH e GOT mRNA nas amostras provenientes do intestino delgado de ratos pré-condicionados com L-Gln ou L-Ala-Gln não apresentou diferenças significativas, tanto durante a isquemia como na fase inicial de reperfusão. CONCLUSÃO: Ativação do ciclo malato-aspartato não parece ser o mecanismo de elevação glutamina-mediada da oxidação da glicose no intestino de ratos durante a isquemia / reperfusão.
Assuntos
Animais , Ratos , Ácido Aspártico/metabolismo , Glutamina/farmacologia , Intestino Delgado/irrigação sanguínea , Malatos/metabolismo , RNA Mensageiro/sangue , Traumatismo por Reperfusão/prevenção & controle , Aspartato Aminotransferases/sangue , Aspartato Aminotransferases/genética , Modelos Animais de Doenças , Dipeptídeos/farmacologia , Intestino Delgado/enzimologia , Malato Desidrogenase/sangue , Malato Desidrogenase/genética , Distribuição Aleatória , Ratos Wistar , Reação em Cadeia da Polimerase em Tempo Real , Traumatismo por Reperfusão/enzimologia , Fatores de TempoRESUMO
AngII (angiotensin II), ACE (angiotensin I-converting enzyme) and the AT1 receptor (AngII type 1 receptor) are associated with the inflammatory process and microvascular dysfunction of AKI (acute kidney injury) induced by renal I/R (ischaemia/reperfusion). However, Ang-(1-7) [angiotensin-(1-7)], ACE2 (angiotensin I-converting enzyme 2) and the Mas receptor also play a role in renal disease models. Therefore, in the present study, we have examined the renal profile of Ang-(1-7), ACE2 and the Mas receptor in renal I/R and compared them with that of AngII, ACE and the AT1 receptor. Male Wistar rats were submitted to left nephrectomy and ischaemia (45 min) followed by reperfusion (2 or 4 h) in the right kidney. At 4 h of reperfusion, renal AngII was increased (P<0.01) and renal Ang-(1-7) was decreased substantially (P<0.05), although plasma levels of both angiotensins were unchanged. In addition, renal I/R decreased the renal mRNA expression of renin (P<0.05), AT1 receptors (P<0.001) and ACE2 (P<0.05). At 2 and 4 h of reperfusion, renal ACE activity was reduced (P<0.05). On the other hand, renal expression of the Mas receptor was greatly increased at 4 h of reperfusion (P<0.01), which was confirmed by immunohistochemical and Western blot analysis. In conclusion, increased renal expression of the Mas receptor associated with changes in the RAS (renin-angiotensin system)-related peptidases support an important role for the ACE2-Ang-(1-7)-Mas axis in AKI.
Assuntos
Angiotensina II/metabolismo , Angiotensina I/metabolismo , Rim/irrigação sanguínea , Fragmentos de Peptídeos/metabolismo , Traumatismo por Reperfusão/enzimologia , Animais , Pressão Sanguínea/fisiologia , Rim/metabolismo , Masculino , Proto-Oncogene Mas , Proteínas Proto-Oncogênicas/metabolismo , Ratos , Ratos Wistar , Receptores Acoplados a Proteínas G/metabolismo , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/fisiopatologia , UrinaRESUMO
OBJECTIVE: This study aimed to assess the catalase activity after ischemia and reperfusion and to study the changes of this antioxidant in organs located far from the initial insult. METHODS: Eighteen Wistar rats were randomly divided into three groups. 1-Control, 2-Simulation and 3-Ischemia and Reperfusion. In the latter it was done an ischemia of the ileum for 60 minutes followed by reperfusion for 30 minutes. In group 2 only laparotomy was performed. From all animals it was taken segments of the reperfused and non reperfused intestine, as well of the right kidney and lung to be evaluated under light microscopy. Catalase activity was measured in spectrophotometer with a wavelength set to 240 nm. It was used Mann Whitney and Kruskal Wallis statistical tests. RESULTS: There was a significant increase (p <0.05) in the catalase activity not only at small bowel ischemic and non-ischemic segments but also at lungs. However the enzymatic activity decreases in the kidney. In all organs studied at reperfusion group it was found a slight villi derangement, mild congestion and infiltration with inflammatory cells, and areas of pulmonary atelectasis. CONCLUSION: The intestinal oxidative stress in rats causes biochemical changes at distance, with mobilization of antioxidant defense mechanisms in lung, non-ischemic intestinal segment and kidney, with early decrease in this last organ, however, with no relevant cellular damage.
Assuntos
Catalase/metabolismo , Intestino Delgado/enzimologia , Rim/enzimologia , Pulmão/enzimologia , Traumatismo por Reperfusão/enzimologia , Animais , Intestino Delgado/patologia , Rim/patologia , Pulmão/patologia , Ratos , Ratos Wistar , Traumatismo por Reperfusão/patologiaRESUMO
OBJETIVO: Avaliar a atividade catalase, após lesão por isquemia e reperfusão intestinal e estudar as alterações deste antioxidante em órgãos situados à distância do insulto inicial. MÉTODOS: Utilizaram-se 18 ratos do tipo Wistar, aleatoriamente distribuídos em três grupos. 1-Controle, 2-Simulação e 3-Isquemia/Reperfusão. Neste último, realizou-se isquemia no íleo, por 60 minutos, seguida de reperfusão por 30 minutos. No grupo 2 efetuou-se apenas uma laparotomia. Foram retirados, de todos os animais, segmentos do intestino com e sem reperfusão, além do pulmão e rim direitos para exame com microscopia óptica. A atividade da catalase foi aferida em espectrofotômetro ajustado para 240 nm. Utilizaram-se os testes estatísticos Mann e Whitney e Kruskal Wallis. RESULTADOS: Observou-se aumento significante (p < 0.05), da atividade da catalase nas porções do intestino isquemiado e não isquemiado, além do pulmão. Houve redução da atividade enzimática no rim. No grupo com reperfusão observaram-se alteração nas vilosidades, infiltrado inflamatório em todas as vísceras, além de áreas de atelectasia pulmonar. CONCLUSÃO: O estresse oxidativo intestinal, em ratos, causa alterações bioquímicas à distância com mobilização dos mecanismos de defesa antioxidante pulmonar, em segmento intestinal não isquemiado e no rim, com esgotamento precoce das reservas deste último, no entanto, sem lesão celular relevante, destas vísceras.
OBJECTIVE: This study aimed to assess the catalase activity after ischemia and reperfusion and to study the changes of this antioxidant in organs located far from the initial insult. METHODS: Eighteen Wistar rats were randomly divided into three groups. 1-Control, 2-Simulation and 3-Ischemia and Reperrfusion. In the latter it was done an ischemia of the ileum for 60 minutes followed by reperfusion for 30 minutes. In group 2 only laparotomy was performed. From all animals it was taken segments of the reperfused and non reperfused intestine, as well of the right kidney and lung to be evaluated under light microscopy. Catalase activity was measured in spectrophotometer with a wavelength set to 240 nm. It was used Mann Whitney and Kruskal Wallis statistical tests. RESULTS: There was a significant increase (p <0.05) in the catalase activity not only at small bowel ischemic and non-ischemic segments but also at lungs. However the enzymatic activity decreases in the kidney. In all organs studied at reperfusion group it was found a slight villi derangement, mild congestion and infiltration with inflammatory cells, and areas of pulmonary atelectasis. CONCLUSION: The intestinal oxidative stress in rats causes biochemical changes at distance, with mobilization of antioxidant defense mechanisms in lung, non-ischemic intestinal segment and kidney, with early decrease in this last organ, however, with no relevant cellular damage.
Assuntos
Animais , Ratos , Catalase/metabolismo , Intestino Delgado/enzimologia , Rim/enzimologia , Pulmão/enzimologia , Traumatismo por Reperfusão/enzimologia , Intestino Delgado/patologia , Rim/patologia , Pulmão/patologia , Ratos Wistar , Traumatismo por Reperfusão/patologiaRESUMO
We evaluated the effects of a substrate in the biosynthesis of nitric oxide (NO)-l-arginine (LARG)-on hepatic lesions caused by ischemia/reperfusion (I/R) injury in rabbit livers. Rabbits were pretreated with LARG (150 mg/kg IV) or saline solution 0.9% (SS) before the hepatic I/R procedure. The effects of LARG on hepatic injury were evaluated before and after I/R. The warm hepatic I/R procedure produced profound acute liver injury, as indicated by elevated values of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactic dehydrogenase (LDH), as well as a high apoptotic cell count. All changes were attenuated by treatment with LARG before the hepatic I/R procedure. These results suggested that LARG produced protective effects on hepatic I/R lesions. This protective effect of LARG was probably associated with blocking generation of superoxide anions during the hepatic I/R procedure.
Assuntos
Arginina/uso terapêutico , Hepatopatias/prevenção & controle , Traumatismo por Reperfusão/prevenção & controle , Alanina Transaminase/sangue , Alanina Transaminase/efeitos dos fármacos , Animais , Aspartato Aminotransferases/sangue , Aspartato Aminotransferases/efeitos dos fármacos , L-Lactato Desidrogenase/sangue , L-Lactato Desidrogenase/efeitos dos fármacos , Circulação Hepática/efeitos dos fármacos , Masculino , Óxido Nítrico/metabolismo , Coelhos , Traumatismo por Reperfusão/enzimologia , Traumatismo por Reperfusão/patologia , Vasoconstrição/efeitos dos fármacosRESUMO
Because the role of heparin (HEP) in hepatic ischemia/reperfusion (I/R) injury is still not fully understood, we investigated the effects of treatment with HEP on hepatic I/R injury in rabbits. For I/R procedures, the portal vein and hepatic artery were occluded by a metallic clamp to promote ischemia. The clamp was removed after 30 minutes to allow reperfusion. Rabbits undergoing the I/R procedure were treated with HEP (100 U/kg) or saline solution 0.9% (SS). When compared with levels before I/R, the serum aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase, levels were increased by the hepatic I/R procedure, among rabbits treated with SS or HEP. However, the increase in these enzymes was lower among rabbits treated with HEP. Histologic analysis of hepatic tissue of rabbits undergoing I/R and treated with SS showed marked lesions in the central lobule with significant inflammatory infiltration. In contrast, a significant reduction in lesions caused by I/R was observed in the livers of rabbits treated with HEP. After starting reperfusion, we visualized apoptotic cells with nuclear staining among rabbits submitted to I/R and treated with SS, but not those treated with HEP. These results suggested that HEP was able to attenuate hepatic lesions caused by I/R in the livers of rabbits.
Assuntos
Heparina/uso terapêutico , Isquemia/tratamento farmacológico , Hepatopatias/tratamento farmacológico , Traumatismo por Reperfusão/prevenção & controle , Alanina Transaminase/efeitos dos fármacos , Alanina Transaminase/metabolismo , Animais , Aspartato Aminotransferases/efeitos dos fármacos , Aspartato Aminotransferases/metabolismo , Modelos Animais de Doenças , Fibrinolíticos/uso terapêutico , Isquemia/enzimologia , L-Lactato Desidrogenase/efeitos dos fármacos , L-Lactato Desidrogenase/metabolismo , Fígado/enzimologia , Hepatopatias/enzimologia , Masculino , Coelhos , Traumatismo por Reperfusão/enzimologiaRESUMO
We investigated whether hepatic artery endothelium may be the earliest site of injury consequent to liver ischemia and reperfusion. Twenty-four heartworm-free mongrel dogs of either sex exposed to liver ischemia/reperfusion in vivo were randomized into four experimental groups (N = 6): a) control, sham-operated dogs, b) dogs subjected to 60 min of ischemia, c) dogs subjected to 30 min of ischemia and 60 min of reperfusion, and d) animals subjected to 45 min of ischemia and 120 min of reperfusion. The nitric oxide endothelium-dependent relaxation of hepatic artery rings contracted with prostaglandin F2a and exposed to increasing concentrations of acetylcholine, calcium ionophore A23187, sodium fluoride, phospholipase-C, poly-L-arginine, isoproterenol, and sodium nitroprusside was evaluated in organ-chamber experiments. Lipid peroxidation was estimated by malondialdehyde activity in liver tissue samples and by blood lactic dehydrogenase (LDH), serum aspartate aminotransferase (AST) and serum alanine aminotransferase (ALT) activities. No changes were observed in hepatic artery relaxation for any agonist tested. The group subjected to 45 min of ischemia and 120 min of reperfusion presented marked increases of serum aminotransferases (ALT = 2989 +/- 1056 U/L and AST = 1268 +/- 371 U/L; P < 0.01), LDH = 2887 +/- 1213 IU/L; P < 0.01) and malondialdehyde in liver samples (0.360 +/- 0.020 nmol/mgPT; P < 0.05). Under the experimental conditions utilized, no abnormal changes in hepatic arterial vasoreactivity were observed: endothelium-dependent and independent hepatic artery vasodilation were not impaired in this canine model of ischemia/reperfusion injury. In contrast to other vital organs and in the ischemia/reperfusion injury environment, dysfunction of the main artery endothelium is not the first site of reperfusion injury.
Assuntos
Endotélio Vascular/fisiopatologia , Artéria Hepática/fisiopatologia , Peroxidação de Lipídeos/fisiologia , Fígado/irrigação sanguínea , Traumatismo por Reperfusão/fisiopatologia , Vasodilatação/fisiologia , Alanina Transaminase/sangue , Animais , Aspartato Aminotransferases/sangue , Cães , Feminino , L-Lactato Desidrogenase/sangue , Masculino , Distribuição Aleatória , Traumatismo por Reperfusão/enzimologiaRESUMO
We investigated whether hepatic artery endothelium may be the earliest site of injury consequent to liver ischemia and reperfusion. Twenty-four heartworm-free mongrel dogs of either sex exposed to liver ischemia/reperfusion in vivo were randomized into four experimental groups (N = 6): a) control, sham-operated dogs, b) dogs subjected to 60 min of ischemia, c) dogs subjected to 30 min of ischemia and 60 min of reperfusion, and d) animals subjected to 45 min of ischemia and 120 min of reperfusion. The nitric oxide endothelium-dependent relaxation of hepatic artery rings contracted with prostaglandin F2a and exposed to increasing concentrations of acetylcholine, calcium ionophore A23187, sodium fluoride, phospholipase-C, poly-L-arginine, isoproterenol, and sodium nitroprusside was evaluated in organ-chamber experiments. Lipid peroxidation was estimated by malondialdehyde activity in liver tissue samples and by blood lactic dehydrogenase (LDH), serum aspartate aminotransferase (AST) and serum alanine aminotransferase (ALT) activities. No changes were observed in hepatic artery relaxation for any agonist tested. The group subjected to 45 min of ischemia and 120 min of reperfusion presented marked increases of serum aminotransferases (ALT = 2989 ± 1056 U/L and AST = 1268 ± 371 U/L; P < 0.01), LDH = 2887 ± 1213 IU/L; P < 0.01) and malondialdehyde in liver samples (0.360 ± 0.020 nmol/mgPT; P < 0.05). Under the experimental conditions utilized, no abnormal changes in hepatic arterial vasoreactivity were observed: endothelium-dependent and independent hepatic artery vasodilation were not impaired in this canine model of ischemia/reperfusion injury. In contrast to other vital organs and in the ischemia/reperfusion injury environment, dysfunction of the main artery endothelium is not the first site of reperfusion injury.
Assuntos
Animais , Cães , Feminino , Masculino , Endotélio Vascular/fisiopatologia , Artéria Hepática/fisiopatologia , Peroxidação de Lipídeos/fisiologia , Fígado/irrigação sanguínea , Traumatismo por Reperfusão/fisiopatologia , Vasodilatação/fisiologia , Alanina Transaminase/sangue , Aspartato Aminotransferases/sangue , L-Lactato Desidrogenase/sangue , Distribuição Aleatória , Traumatismo por Reperfusão/enzimologiaRESUMO
INTRODUCTION: Ischemia/reperfusion injury (IRI) represents the single major antigen-independent factor implicated in pathogenesis of chronic graft dysfunction. Tacrolimus is a calcineurin inhibitor, which has been suggested to be helpful in cyclosporine-related chronic toxicity. Rapamycin has antiproliferative properties that may impair renal regeneration after IRI. Therefore, immunosuppressive drugs might impair renal graft outcome in those organs suffering IRI. MATERIAL AND METHODS: C57B1/6 male mice subjected to 45 minutes of renal pedicle ligation were reperfused for 24 hours. Mice were treated with rapamycin, cyclosporine, or tacrolimus. Blood and renal tissue samples were collected at 24 hours after IRI. Urea levels were measured. Heme Oxygenase 1 (HO-1) gene transcript was amplified by a real-time polymerase chain reaction technique. RESULTS: Animals treated with cyclosporine and subjected to IRI showed impaired renal function that peaked at 24 hours. Additional pretreatment with rapamycin produced even more impairment of renal function, when compared with controls. However, tacrolimus pretreatment was associated with a better renal outcome. HO-1 expression was upregulated after IRI by 2.6 arbitrary units at 24 hours. Rapamycin showed worse impairment of renal function. CONCLUSION: Tacrolimus was not associated with worsening renal function when compared with animals just subjected to IRI. Upregulation of HO-1 may be an attractive approach to limit graft injury.
Assuntos
Heme Oxigenase-1/genética , Imunossupressores/toxicidade , Nefropatias/imunologia , Traumatismo por Reperfusão/imunologia , Transcrição Gênica , Animais , Ciclosporina/efeitos adversos , Nefropatias/enzimologia , Nefropatias/fisiopatologia , Testes de Função Renal , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Reação em Cadeia da Polimerase , Traumatismo por Reperfusão/enzimologia , Traumatismo por Reperfusão/fisiopatologia , Sirolimo/efeitos adversos , Tacrolimo/efeitos adversosRESUMO
Ischemia and reperfusion injury (IRI) is the main etiology of acute renal failure in native and transplanted kidneys. In the transplantation field, immunosuppressive drugs may play an additional role in acute graft dysfunction. Rapamycin may impair renal regeneration post IRI. Heme oxygenase 1 (HO-1) is a protective gene with anti-inflammatory and anti-apoptotic actions. We investigated whether HO-1 played a role in rapamycin-induced renal dysfunction in an established model of IRI. Rapamycin (3 mg/kg) was administered to mice before being subjected to 45 min of ischemia. Animals subjected to IRI presented with impaired renal function that peaked at 24 h (2.05+/-0.23 mg/dl), decreasing thereafter. Treatment with rapamycin caused even more renal dysfunctions (2.30+/-0.33 mg/dl), sustained up to 120 h after reperfusion (1.54+/-0.4 mg/dl), when compared to the control (0.63+/-0.09 mg/dl, P<0.05). Rapamycin delayed tubular regeneration that was normally higher in the control group at day 5 (68.53+/-2.30 vs 43.63+/-3.11%, P<0.05). HO-1 was markedly upregulated after IRI and its expression was even enhanced by rapamycin (1.32-fold). However, prior induction of HO-1 by cobalt protoporphyrin improved the renal dysfunction imposed by rapamycin, mostly at later time points. These results demonstrated that rapamycin used in ischemic-injured organs could also negatively affect post-transplantation recovery. Modulation of HO-1 expression may represent a feasible approach to limit rapamycin acute toxicity.
Assuntos
Heme Oxigenase-1/metabolismo , Imunossupressores/efeitos adversos , Rim/efeitos dos fármacos , Traumatismo por Reperfusão/fisiopatologia , Sirolimo/efeitos adversos , Injúria Renal Aguda/enzimologia , Injúria Renal Aguda/etiologia , Injúria Renal Aguda/fisiopatologia , Animais , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Regulação Enzimológica da Expressão Gênica/genética , Heme Oxigenase-1/genética , Imunossupressores/farmacologia , Rim/patologia , Rim/fisiopatologia , Transplante de Rim/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Protoporfirinas/farmacologia , Traumatismo por Reperfusão/complicações , Traumatismo por Reperfusão/enzimologia , Sirolimo/farmacologiaRESUMO
The aim of the present work was to study the effects of an unilateral ischaemic-reperfusion injury on Na+, K+-ATPase activity, alpha1 and beta1 subunits protein and mRNA abundance and ATP content in cortical and medullary tissues from postischaemic and contralateral kidneys. Right renal artery was clamped for 40 min followed by 24 and 48 h of reperfusion. Postischaemic and contralateral renal function was studied cannulating the ureter of each kidney. Postischaemic kidneys after 24 (IR24) and 48 (IR48) hours of reperfusion presented a significant dysfunction. Na+, K+-ATPase alpha1 subunit abundance increased in IR24 and IR48 cortical tissue and beta1 subunit decreased in IR48. In IR24 medullary tissue, alpha1 abundance increased and returned to control values in IR48 while beta1 abundance was decreased in both periods. Forty minutes of ischaemia without reperfusion (I40) promoted an increment in alpha1 mRNA in cortex and medulla that normalised after 24 h of reperfusion. beta1 mRNA was decreased in IR24 medullas. No changes were observed in contralateral kidneys. This work provides evidences that after an ischaemic insult alpha1 and beta1 protein subunit abundance and mRNA levels are independently regulated. After ischaemic-reperfusion injury, cortical and medullary tissue showed a different pattern of response. Although ATP and Na+, K+-ATPase activity returned to control values, postischemic kidney showed an abnormal function after 48 h of reflow.