ABSTRACT
PURPOSE: To assess the effect of two laser wavelengths, either separate or combined, on intact rat livers. METHOD: Nineteen male Wistar rats (200-300 g) were submitted to laser irradiation at 5 different sites on the liver surface.Wavelengths 660 and 780 nm were used, with a dose of irradiation of 60 J/cm2/site.The animals were divided into the groups:control (C) and animals irradiated with 660 nm laser (L1), with 780 nm laser (L2) or withboth wavelengths (L3).Mitochondrial function, mitochondrial swelling, and hepatocellular malondialdehyde (MDA) levels were determined.Data were analyzed by the Mann-Whitney test, with the level of significance set at 5%. RESULTS: There was a reduction of ADP-activated respiration (state 3) in group L1 compared to group C (p=0.0016), whereas the values of group L2 were similar to control.Group L3 also showed a reduction of state 3 (p=0.0159).There was a reduction of RCR in group L1 compared to control (p=0.0001) and to group L2 (p=0.0040).Mitochondrial swelling only differed between group L3 and control (p=0.0286).There was a increase in MDA levels in group L3 compared to control (p=0.0476) and to group L2 (p=0.0286) and in group L1 compared to group L2 (p=0.0132). CONCLUSION: Although laser irradiation reduced mitochondrial function,it did not interfere with the hepatocellular energy status.
Subject(s)
Animals , Male , Mitochondria, Liver/radiation effects , Oxidative Stress/radiation effects , Lasers, Semiconductor , Liver/radiation effects , Radiation Dosage , Spectrophotometry , Time Factors , Rats, Wistar , Low-Level Light Therapy , Dose-Response Relationship, Radiation , Malondialdehyde/analysis , Mitochondrial Swelling/drug effectsABSTRACT
PURPOSE: To evaluate the effects of hyperbaric oxygen on rats submitted to hepatic ischemia and reperfusion. METHODS: Twenty-three Wistar rats were divided at random into 3 groups: SHAM, rats submitted to surgical and anesthetic stress without induction of hepatic ischemia/reperfurion; I/R, rats submitted to total ischemia of the hepatic pedicle for 25 min followed by 5 min of reperfusion; HBOI/R, rats submitted to 60 min of hyperbaric oxygen therapy at a pressure of 2 absolute atmospheres immediately after the experimental protocol of ischemia/reperfusion. Hepatic function was evaluated by quantitation of serum alanine aminotranferase (ALT) and aspartate aminotransferase (AST), and by mitochondrial function through the determination of states 3 and 4 of mitochondrial respiration, respiratory control ratio (RCR) and mitochondrial swelling. Data were analyzed by the Mann-Whitney test, with the level of significance set at p <0.05. RESULTS: There was a significant difference in state 3 values for the SHAM group vs I/R and I/R vs IRHBO, in state 4 values for the SHAM group vs I/R; and in mitochondrial swelling for the SHAM groups vs I/RHBO, SHAM vs I/R, and IR vs I/RHBO. CONCLUSION: The use of hyperbaric oxygen after I/R improved in a relative manner both the production of energy and the effects on the mitochondrial wall. .
Subject(s)
Animals , Male , Hyperbaric Oxygenation/methods , Liver/blood supply , Reperfusion Injury/therapy , Alanine Transaminase/blood , Aspartate Aminotransferases/blood , Cell Respiration , Mitochondria, Liver/physiology , Random Allocation , Rats, Wistar , Reproducibility of Results , Time Factors , Treatment OutcomeABSTRACT
PURPOSE: To determine the effect of hyperbaric hyperoxia as hepatic preconditioning on hepatocellular integrity in rats submitted to intermittent hepatic ischemia/reperfusion injury. METHODS: Twenty male Wistar rats were divided into 4 groups (SHAM, I/R, HBO-I/R and CONTROL). The surgical technique consisted of total clamping of the hepatic pedicle for 15 min, followed by reperfusion for 5 min, performed twice. The application of hyperbaric oxygen (HBO) was carried out in a collective chamber (simultaneous exposure of 4 rats) pressurized directly with oxygen at 2 ATA for 60 min. Tissue malondialdehyde (MDA) levels were determined and blood samples were collected for the determination of serum AST and ALT levels. Data were analyzed statistically by the Mann-Whitney test, with the level of significance set at p < 0.05. RESULTS: A statistically significant difference in MDA (p< 0.05) was observed between control and HBO-I/R, but not between control and I/R. Regarding AST, there was a difference between control and I/R and HBO-I/R. Analysis of ALT revealed a significant difference between control and I/R (p<0.05) and between I/R and HBO-I/R, with no difference between control and HBO-IR. CONCLUSION: Hyperoxic preconditioning proved to be favorable regarding alanine transaminase, but not aspartate aminotranserase or malondialdehyde levels. .
Subject(s)
Animals , Male , Hyperbaric Oxygenation/methods , Ischemic Preconditioning/methods , Liver/blood supply , Reperfusion Injury/therapy , Alanine Transaminase/blood , Aspartate Aminotransferases/blood , Malondialdehyde/analysis , Mitochondria, Liver/physiology , Rats, Wistar , Reproducibility of Results , Time Factors , Treatment OutcomeABSTRACT
PURPOSE: To evaluate the effect of the hyperbaric oxygen (HBO) treatment as a pre-conditioning for I/R effects in the liver ischemia. METHODS: Fifty-seven male Wistar rats (260-300g) were submitted to the following procedures: SHAM; I/R, rats submitted to I/R, consisting of partial ischemia of 70% of the liver for 90 minutes followed by 15 minutes of reperfusion; HBO I/R 1 ATA, 30 minutes of HBO treatment at the pressure of 1 absolute atmosphere (ATA) during the ischemia time. HBO I/R 2 ATA, 30 minutes of HBO (2 ATA) during the ischemia time. Pre HBO I/R 30', rats submitted to 30 minutes of HBO (2 ATA) immediately before the I/R time. Pre HBO I/R 90', rats submitted to 90 minutes of HBO (2 ATA) immediately before the I/R time. RESULTS: There was a significant worsening of all the parameters of mitochondrial energy production (state 3, 4, RCR and Swelling) in the I/R group, when compared to the Sham group (I/R <Sham, p<0.05). There was also a significant worsening in state 4, RCR and mitochondrial edema in the Pre HBO I/R 90' group compared to the I/R group. Hepatic enzyme concentrations were significantly higher in the I/R group. CONCLUSION: The use of hyperbaric oxygen before and during I/R did not improve the production of hepatocellular energy reduced by I/R, nor did it prevent the installation of mitochondrial edema induced by Iischemia/reperfusion. .
Subject(s)
Animals , Male , Hyperbaric Oxygenation/methods , Ischemic Preconditioning/methods , Liver/blood supply , Reperfusion Injury/therapy , Alanine Transaminase/blood , Aspartate Aminotransferases/blood , Cell Respiration , Edema/etiology , Mitochondria, Liver/physiology , Mitochondrial Diseases/etiology , Rats, Wistar , Reproducibility of Results , Time Factors , Treatment OutcomeABSTRACT
FUNDAMENTO: São numerosas as vantagens de se fechar a cavidade pericárdica após as operações cardíacas e pneumonectomias intrapericárdicas. OBJETIVO: Estudar o comportamento da membrana de látex natural como substituto parcial do pericárdio. MATERIAL E MÉTODOS: Em 16 cães, divididos em 3 grupos, ressecou-se um retalho elíptico da porção ântero-lateral esquerda do pericárdio (7 cm x 5 cm): Grupo A (n=4) - o retalho removido foi reimplantado imediatamente; Grupo B (n=8) - o retalho foi substituído por outro, de látex natural, com área equivalente e espessura de 0,3 mm; Grupo C (n=4) - retalho de látex de 0,7 mm de espessura. Em todos os animais, fixou-se o retalho com sutura contínua de fio de polipropileno 5-0 ou 6-0. No último grupo, foram dados 4 pontos adicionais, em U, ancorados em barras de dacron. Realizaram-se eletrocardiogramas (ECG) e leucogramas no pré e no pós-operatório, bem como estudo macro e microscópio post-mortem. RESULTADOS: Grupo A - auto-enxerto íntegro, macro e microscopicamente, fortemente aderido ao pulmão e frouxamente aderido ao epicárdio; Grupo B - deiscência parcial da sutura em 1 e total em 2 animais. A membrana de látex não aderiu nem ao pulmão nem ao epicárdio. Em 3 (37,5 por cento) animais houve regeneração total e distinta do pericárdio subjacente ao látex, microscopicamente idêntico ao pericárdio nativo. Grupo C - suturas íntegras. Em 3 (75 por cento) animais observou-se regeneração pericárdica total e distinta. Nos demais animais dos Grupos B e C, e epicárdio subjacente ao látex apresentava-se ligeiramente espessado, permitindo visibilizar os vasos coronários com facilidade. Microscopicamente, identificaram-se algumas áreas com denso infiltrado linfo-plasmocitário, proliferação fibroblástica e vascular; em outras, os fibroblastos circunscreviam fendas com revestimento mesotelial, indicativas de regeneração irregular do pericárdio. Não se observou infecção local nem alteração do leucograma e ao ECG, apenas inversão da onda T, em todos os grupos. CONCLUSAO: A membrana de látex natural mostrou-se adequada para a substituição parcial do pericárdio de cães, em observação de até 345 dias, propiciando a regeneração do pericárdio nativo
Subject(s)
Animals , Male , Female , Dogs , Latex/therapeutic use , Membranes, Artificial , Pericardium/surgery , Prostheses and Implants , Pericardium/physiology , RegenerationABSTRACT
O objetivo do presente estudo é avaliar a sensibilidade dos níveis séricos da fosfatase alcalina (FA) e da gama-glutamil transferase (GGT) como indicadores da colestase extra-hepática (CEH) em ratos. Foram estudados 71 ratos machos Wistar (270-330g) com CEH induzida experimentalmente por ligadura do ducto biliar. Os animais foram sacrificados 1 (n=10), 7 (n=17) e 14 (n=12) após a induçäo da colestase, juntamente com 10 animais controles submetidos a operaçäo simulada para cada tempo de CEH, quando amostras de sangue foram colhidas para dosagens séricas da GGT e FA e Bilirrubinas totais (BT). Todos os animais com CEH ficaram ictéricos e com valores de bilirrubinas significativamente maiores que os controles. Os valores de FA e GGT um, 7 e 14 dias após induçäo da CEH foram respectivamente de : FA = 429ñ 90; 223 ñ 26 e 184 ñ 30 (U/I); GGT = 8 ñ 5; 24 ñ 10 e 24 ñ 9 (U/I). A sensibilidade em // da GGT foi ), 10,7 e 8,3 com 1,7 e 14 dias de CEH, respectivamente: e da FA foi 100// nos três tempos de induçäo da colestase. Estes achados mostram que o nível sérico de GGT é pouco sensível como indicador da colestase extra-hepática e que a enzima ideal para isso é a fosfatase alcalina sérica