Abstract Introduction: There are many reasons to believe that the nitric oxide/guanosine 3’5’ - cyclic monophosphate (or NO/cGMP) pathway on vasoplegic states is underestimated. To study indigo carmine (IC) as an alternative to methylene blue was the investigation rationale. Methods: The IC (3mg/kg intravenous infusion) study protocol included five experimental groups; 1) Control group — saline was injected at 0 and 10 minutes; 2) IC group — IC was injected at 0 and saline at 10 minutes; 3) compound 48/80 (C48/80) group — C48/80 was injected at 0 minute and saline at 10 minutes; 4) C48/80 + IC group — C48/80 was injected at 0 minute and IC at 10 minutes; and 5) IC + C48/80 group — IC was injected at 0 minute and C48/80 at 10 minutes. The studies were carried out by registering and measuring hemodynamic and blood gasometric parameters, including continuous cardiac output. Results: 1) The effects of the drugs (IC and C48/80) were more evident in the first 20 minutes of recording; 2) hypotensive responses were more pronounced in the C48/80 groups; 3) IC isolated or applied before C48/80 caused transient pulmonary hypertension; and 4) after the first 20 minutes, the pressure responses showed stability with apparent hypotension more pronounced in the C48/80 groups. Clinical observations showed significant hemodynamic instability and catastrophic anaphylactic reactions (agitation, pulmonary hypertension, severe bronchospasm, urticaria, high-intensity cyanosis, violent gastric hypersecretion, and ascites). Conclusion: A global results analysis showed differences between groups only in the first 20 minutes of the experiments.

Abstract Purpose To evaluate the effects of treatment with Indigo Carmine (IC) on rat livers subjected to ischemia-reperfusion injury. Methods The animals were subdivided into 4 groups: 1.SHAM group(SH) - saline; 2.SHAM group with IC-2mg/Kg(SHIC); 3.IR group - rats submitted to ischemia and reperfusion with saline(IR); 4.IR group with IC-2mg/Kg(IRIC). The IR protocol consists of liver exposure and administration of drug or saline intravenously, followed by 60 minutes of ischemia and 15 of reperfusion. Liver samples were collected for biochemical analysis. Results State 3 of mitochondrial respiration showed a significant worsening of the IRIC group in relation to all others. State 4 showed a difference between IRIC and SHIC. The Respiratory Control Ratio showed statistical decrease in IR and IRIC versus Sham. The osmotic swelling showed significant difference between SHxIR; SHICxIRIC and SHxIRIC. There was a significant increase in ALT in the IRIC group in relation to all the others. Concerning the nitrate dosage, there was a decrease in the group treated with IC(IRxIRIC). There was no difference regarding the dosage of Malondialdehyde. Conclusion IC was not able to protect mitochondria from IR injury and proved to be a potentiating agent, acting in synergy with the IR injury promoting damage to the hepatocyte membranes.

Abstract Purpose To compare Fructose-1,6-Bisphosphate (FBP) to Histidine-Tryptophan-Ketoglutarate (HTK) in liver preservation at cold ischemia. Methods Male rats (Sprague-Dawley: 280-340g) divided into three groups (n=7): Control; Fructose-1,6-bisphosphate (FBP); Histidine-Tryptophan-Ketoglutarate (HTK). Animals underwent laparotomy-thoracotomy for perfusion of livers with saline. Livers were removed and deposited into solutions. Mitochondria were isolated to determine State 3 (S3), State 4 (S4), Respiratory Control Ratio (RCR) and Swelling (S). Liver enzymes (AST, ALT, LDH) were determined in solution. At tissue, Malondialdehyde (MDA) and Nitrate (NOx) were determined. All parameters were analyzed at 0.6 and 24 hours of hypothermic preservation. Statistics analysis were made by Mann-Whitney test (p<0.05). Results Regarding ALT, there was a difference between FBP-6h/HTK-6h, lower in HTK. Regarding AST, there was a significant difference between FBP-24h/HTK-24h, lower in FBP. Regarding NOx, there was a difference between 0h and 6h, as well as 0h and 24h for both solutions. Regarding S3, there was a significant difference in 24h compared to Control-0h for both solutions, and a significant difference between FBP-6h/FBP-24h. Regarding S4, there was a difference between Control-0h/HTK-24h and FBP-24h/HTK-24h, higher in HTK. There was a difference between Control-0h/FBP-24h for Swelling, higher in FBP. Conclusion Fructose-1,6-Bisphosphate showed better performance at nitrate and aspartate aminotransferase compared to histidine-tryptophan-ketoglutarate.

Abstract 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.

Abstract Purpose: To evaluate whether pre-treatment with rivastigmine is able to attenuate the I/R induced lesions in rat liver. Methods: SHAM animals or those submitted to I/R, non-treated or pre-treated with rivastigminine (2mg/kg) either 50 or 15 minutes before ischemia, were used. After I/R protocol, these animals were killed and their livers were harvested to measurement of the mitochondrial swelling as well as the malondialdehyde (MDA), nitrite and nitrate tissue concentration. Blood was also harvested for serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) determinations. Results: I/R promoted a significant increase of mitochondrial swelling in the studied animals. This increase of mitochondrial swelling was partially prevented by rivastigmine, but only if administered 50 minutes before ischemia. No significant modification of MDA, nitrite or nitrate tissue concentrations was observed in consequence of I/R, followed or not by rivastigmine treatments. In addition, I/R elevated both AST and ALT. These elevations of serum enzymes were not reversed by the different rivastigmine treatments. Conclusions: Rivastigmine administered 50 minutes before ischemia attenuates I/R-induced mitochondrial swelling, that indicates liver injury. This protective effect may be related to a greater stimulation of α7nAChR present in the Kupffer cells by the non-methabolized ACh, leading to an attenuation of I/R-induced inflammation.

Abstract It is well known that during hepatic operative procedures, it is often critical that the irrigation is interrupted to avoid possible bleeding, blood transfusions, variable intensities, and their short and long-term consequences. It was believed in the past that the flow interruption should not exceed 20 minutes, which limited the use of this maneuver. However, it has been postulated that ischemia could be maintained for more than 60 minutes in healthy livers. The present paper review includes: 1) A brief introduction to justify the rationale of the review design; 2) Aspects of the pathophysiology of the three stages of the liver ischemia-reperfusion injury; 3) The innate and acquired immunity; 4) Oxidative stress; 5) Apoptosis and autophagy, Some essential biomarkers (Tumor Necrosis Factor-α, nitric oxide, metalloproteinases); and, finally; 6) Preventive (“cheating”) strategies, non-pharmacological and pharmacological options to treat the liver IR injury.

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.

PURPOSE: To investigate the consequences of the association between hyperbaric oxygen therapy and hepatic ischemia / reperfusion. METHODS: Wistar rats were divided into three groups: SHAM, rats submitted to surgical stress and anesthetic but not hepatic ischemia or reperfusion, I / R, rats submitted to total hepatic pedicle ischemia for 30 min, followed by 5 min of reperfusion; HBO120, rats submitted to 120 min of hyperbaric oxygen therapy at two absolute atmospheres and immediately after submitted to the experimental protocol of ischemia and reperfusion. The preservation of the hepatic function was evaluated by determining mitochondrial swelling and malondialdehyde tissue level, as well as alanine aminotransferase and aspartate aminotranferase serum levels. The results were analyzed using the Mann-Whitney test and differences were considered significant for p<0.05. RESULTS: There were significant differences in values: mitochondrial swelling of the I / R group compared to SHAM and HBO120; malondialdehyde between SHAM vs. I / R, SHAM vs HBO120, and I / R vs HBO120, alanine aminotransferase between SHAM vs. I / R . There was no significant difference between groups in aspartate aminotransferase serum levels. CONCLUSION: The association between hyperbaric oxygen therapy and hepatic ischemia and reperfusion process was positive.

OBJETIVO: Avaliar os efeitos da oxigenoterapia hiperbárica (HBO), como pré-condicionamento, em lesão hepática de isquemia/reperfusão intermitente. MÉTODOS: Foram avaliados 36 ratos Wistar machos, distribuídos em 4 grupos (SHAM, I/R , HBO - I/R e CONTROLE). A técnica operatória consistiu em pinçamento total do pedículo hepático durante 15min, seguido de reperfusão por 5 min (desclampeamento), por duas vezes. A aplicação de HBO foi realizada em câmara coletiva (exposição simultânea de 4 ratos) diretamente pressurizada com oxigênio a 2ATA, durante 60min. Determinou-se a função mitocondrial hepática através de amostras do lobo mediano colhidas com exatos 5min de reperfusão para análise da respiração mitocondrial, através da determinação dos estados 3 e 4, razão de controle respiratório e transição de permeabilidade mitocondrial (intumescimento osmótico - swelling mitocondrial).Os resultados foram analisados pelo teste de Mann-Whitney e foi considerado significativo todo valor de p < 0,05. RESULTADOS: Houve diferença estatistica significativa (p< 0,05) no Estado 3 nos grupos CONTROLE vs I/R e HBO - I/R, no Estado 4 nos grupos CONTROLE vs I/R e HBO - I/R; na Razão de controle respiratório(RCR) nos grupos CONTROLE vs I/R e HBO-IRe CONTROLE vs Sham e no Swelling mitocondrial nos grupos CONTROLE vs I/R e HBO - I/R, I/R vs HBO-IRe Sham vs I/R e HBO-IR. CONCLUSÃO: O pré-condicionamento hiperbárico não melhorou a função mitocondrial hepática significativamente neste processo de isquemia e reperfusão intermitente.

PURPOSE: to assess the effect of hyperbaric oxygen (HBO) as pre-conditioning on periodic liver ischemia/reperfusion injury. METHODS: Thirty-six 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 twice repeated reperfusion for 5 min (unclamping). HBO was applied in a collective chamber (simultaneous exposure of 4 rats) directly pressurized with oxygen at 2 ATA for 60 min. Hepatic mitochondrial function was determined using samples of the median lobe obtained after exactly 5 min of reperfusion for the analysis of mitochondrial respiration based on the determination of states 3 and 4, the respiratory control ratio and the transition of mitochondrial permeability (mitochondrial swelling).Data were analyzed by the Mann-Whitney test and the level of significance was set at p < 0.05. RESULTS: There was a statistically significant difference (p< 0.05) in state 3 between the CONTROL and I/R and HBO-I/R groups, in state 4 between the CONTROL and I/R and HBO-I/R groups; in respiratory control ratio (RCR) between the CONTROL and I/R and HBO-I/R groups and between the CONTROL and Sham groups, and in mitochondrial swelling between the CONTROL and I/R and HBO-/R groups and between the Sham and I/R and HBO-I/R groups. CONCLUSION: In this process of periodic ischemia and reperfusion, hyperbaric pre-conditioning did not improve significantly hepatic mitochondrial function.

OBJETIVO: Analisar os efeitos da oxigenoterapia hiperbárica sobre a função hepática de ratos previamente submetidos à isquemia e reperfusão. MÉTODOS: Realizou-se a distribuição aleatória de 23 ratos Wistar em três grupos: SHAM, animais submetidos ao estresse cirúrgico sem restrição de fluxo sanguíneo por clampeamento do pedículo hepático; IR ratos submetidos a oclusão vascular hepática de maneira intermitente em dois ciclos completos de 15 minutos de isquemia, seguidos por 5 min de reperfusão; IR/HBO, ratos submetidos ao clampeamento do pedículo hepático e ,ulteriormente , expostos a oxigenoterapia hiperbárica a pressão de 2 atmosferas absolutas durante 60 minutos. Avaliou-se a função hepática através da função mitocondrial, determinada pelos estados 3 e 4 da respiração mitocondrial, razão de controle respiratório(RCR) e transição de permeabilidade mitocondrial (Swelling) .Quantificou-se também alanina aminotransferase e aspartato aminotransferase séricas. Analisou-se os resultados pelo teste de Mann-Whitney e foram considerados significativos os valores de p < 0,05. RESULTADOS:Houve diferença significativa nos valores do estado 3 no grupo SHAM vs IR; estado 4 nos grupos SHAM vs IR, SHAM vsIR/HBO; Razão de Controle Respiratório(RCR) no grupo IR vs IR/HBO; alanina aminotransferase nos grupos SHAM vs IR, SHAM vs IR/HBO, IR vs IR/HBO; aspartato aminotransferase nos grupos SHAM vs IR , SHAM vs IR/HBO. CONCLUSÃO: A análise dos parâmetros mitocondriais como um todo permitiu concluir que a oxigenoterapia hiperbárica atuou como agente protetor da função mitocondrial, minimizando os efeitos deletérios da lesão de isquemia e reperfusão do parênquima hepático.

PURPOSE: To analyze the effects of hyperbaric oxygen therapy on liver function in rats previously subjected to ischemia and reperfusion. METHODS: A randomly distribution of 23 Wistar rats was conducted into three groups: SHAM, animals subjected to surgical stress without restricting blood flow by clamping the hepatic pedicle, IR, rats underwent hepatic vascular occlusion intermittently for two complete cycles of 15 minutes of ischemia followed by 5 min of reperfusion, IR / HBO, rats underwent hepatic pedicle clamping and thereafter exposed to hyperbaric oxygen pressure of 2 absolute atmospheres for 60 minutes. We evaluated liver function through mitochondrial function, determined by the stages 3 and 4 of respiration, respiratory control ratio (RCR) and mitochondrial permeability transition (Swelling). Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were also quantified . We analyzed the results using the Mann-Whitney test and were considered significant all results with p <0.05. RESULTS: There were significant differences between the results of stage 3 in SHAM vs IR group ; of the stage 4 in the groups IR vs SHAM and SHAM vs IR /HBO; of the Respiratory Control Ratio (RCR) in the group IR vs IR / HBO ; of alanine aminotransferase in the groups IR vs SHAM , SHAM vs IR/HBO and IR vs IR / HBO; aspartate aminotransferase in the groups SHAM vs IR and SHAM vs IR / HBO. CONCLUSION: The whole analysis of the mitochondiral function indicators permits us to conclude that the hyperbaric oxygen therapy acted as a protective agent of the mitochondrial function, minimizing the ischemia-reperfusion injury of the hepatic parenchyma.

OBJETIVO: Avaliar as vantagens e desvantagens da oclusão vascular parcial do fígado durante ressecções hepáticas parciais. MÉTODOS: Cento e quatorze pacientes foram submetidos a hepatectomia parcial(ressecção maior versus ressecção menor) com liver partial vascular exclusion (LPVE) sendo utilizada em 57 deles. A idade dos pacientes variou entre 35 e 73 anos e 57% deles eram mulheres. A função mitocondrial foi avaliada por método polarografico avaliada 30 minutos após a ressecção hepática no fígado remanescente, e o perfil das aminotransferase foi determinado antes da cirurgia e durante sete dias de pós-operatório. A EVPH variou de 30 a 60 minutos. Dados foram analisados estatisticamente pelo teste T Student (nível de significância de 5%). RESULTADOS: Nas ressecções hepáticas maiores e menores, a função mitocondrial do fígado remanescente foi semelhante dos dois grupos. O pico máximo de aminotransferases ocorreu as 24 horas de pós-operatório e o perfil enzimático de ALT e AST foi semelhante nos grupos estudados ( minor vs major hepatectomy.) CONCLUSÃO: A EVPH não induziu alterações mitocondriais no tecido hepático em qualquer tipo de cirurgia, e os níveis de aminotransferases foram similares para pacientes hepatectomizados com e sem LPVE.Assim a LPVE foi um procedimento seguro que não induziu alterações significativas típicos de isquemia e reperfusão no fígado remanescente.

PURPOSE: The aim of the present study was to assess the advantages and disadvantages of liver vascular partial exclusion (LVPE) (liver dysfunction due to ischemia) during liver resection in patients submitted to partial hepatectomy. METHODS: A total of 114 patients were submitted to partial hepatectomy (minor versus major resections) with LPVE being used in 57 of them but not in the remaining 57. Patient age ranged from 35 to 73 years and 57 % were women. Mitochondrial function was assessed 30 minutes after liver resection in the remnant liver and serum aminotransferases were determined before surgery and for seven days postoperatively. LPVE time ranged from 30 to 60 minutes. Data were analyzed statistically by the Student T test (5 % level of significance). RESULTS: Mitochondrial function was similar in the minor and major liver resections. The maximum postoperative aminotransferase peak was similar in the groups with and without LPVE. CONCLUSION: LPVE did not induce mitochondrial changes in hepatic tissue in either type of surgery, and aminotransferase levels were similar for patients with and without LPVE. Thus, the results show that LPVE is a safe procedure that does not induce the significant changes typical of ischemia and reperfusion in the liver remnant.

OBJETIVO: A proposta deste trabalho é avaliar a capacidade de produção energética do miocárdio mediante análise da respiração mitocondrial em ratos ictéricos submetidos à ligadura do ducto biliar. MÉTODOS: Foram utilizados 16 ratos Wistar machos divididos em 2 Grupos: Grupo SO , os quais foram submetidos à Laparotomia branca e Grupo IC, os quais sofreram ligadura do ducto biliar para o desenvolvimento de icterícia obstrutiva. Todos os animais após 7 dias de cirurgia foram submetidos à nova laparotomia para extração e análise do músculo cardíaco. O consumo de oxigênio pelas mitocôndrias foi determinado pela velocidade do estado 3 e velocidade do estado 4. A razão do controle respiratório (RCR) foi obtida pela relação entre as velocidades dos estados 3 e 4. A análise estatística foi feita pelo teste de Mann-Whitney com nível de significância de 5 % (p<0.05). RESULTADOS: Observou-se queda estatisticamente significante nos valores do consumo de oxigênio do estado 3 da respiração mitocondrial no grupo IC em relação ao SO, no entanto os valores para estado 4 permaneceram basicamente inalterados entre os grupos. Os valores de RCR entre os grupos também apresentaram diminuição significativa. CONCLUSÃO: A respiração celular do 'coração ictérico' está deprimida em decorrência da redução da capacidade da mitocôndria cardíaca em consumir oxigênio e sintetizar ATP, o que pode contribuir para a disfunção cardiovascular na vigência da colestase.

PURPOSE: The objective of the present study was to evaluate the capacity of the myocardium for energy production by the analysis of mitochondrial respiration in rats with jaundice submitted to bile duct ligature. METHODS: Sixteen male Wistar rats were divided into 2 Groups: Group SO submitted to nontherapeutic laparotomy (sham operation) and Group IC (icteric group) submitted to bile duct ligature. After 7 days, laparotomy was again performed in all animals for cardiac muscle extraction and analysis. Mitochondrial oxygen consumption was determined by stage 3 velocity and stage 4 velocity. The respiratory control ratio (RCR) was obtained by the ratio of stage 3 to stage 4 velocity. Statistical analysis was performed by the Mann-Whitney test, with the level of significance set at 5% (p<0.05). RESULTS: Statistical analysis revealed a significant drop in oxygen consumption during stage 3 mitochondrial respiration in group IC compared with SO, whereas the values obtained during stage 4 were basically identical for the two groups. Likewise, RCR values exhibited a significant reduction. CONCLUSION: The cellular respiration of the "jaundiced heart" is depressed. This was demonstrated by the reduced capacity of cardiac mitochondria to consume oxygen and synthesize ATP, supporting the idea of a latent cardiac impairment responsible for the hemodynamic decompensation occurring during cholestasis.

OBJETIVO: O objetivo deste estudo foi determinar a influência do pré-condicionamento isquêmico (IPC) em fígados de ratos cirróticos. MÉTODOS: A cirrose hepática foi induzida em ratos Wistar machos (250 a 300g) por oclusão, durante 30 dias, do ducto hepático comum.A seguir, os animais cirróticos foram divididos em três grupos de seis; Grupo controle cirrótico (operação simulada para isquemia/reperfusão/pré-condicionamento), Grupo I/R, isquemia de 40 minutos sem pré-condicionamento (IPC) e grupo IPC com isquemia precedida por IPC. O IPC consistiu de uma isquemia parcial por cinco minutos, seguida por 10 minutos de reperfusão. No grupo IPC, após o pré-condicionamento, os animais foram submetidos à isquemia hepática de 40 minutos seguida de 2 horas de reperfusão. Foram colhidas amostras de sangue para dosagem sérica de aminotransferases (ALT e AST). Razão de controle respiratório (RCR), potencial de membrana das mitocôndrias (PMM) e dosagem de malondialdeído (MDA) foram analisadas no tecido hepático. Analise estatística não paramétrica foi utilizada com nível de significância de 5% para as comparações entre grupos. RESULTADOS: A isquemia não induziu aumento significativo das aminotransferases. Houve aumento significativo de MDA nos animais cirróticos.O PMM não se alterou significativamente na cirrose e na isquemia hepática. A RCR mitocondrial diminuiu na cirrose hepática e acentuou-se com a isquemia do fígado e não se alterou significativamente com o IPC. CONCLUSÃO: O pré-condicionamento isquêmico não protegeu o fígado das lesões hepáticas induzidas pelo processo de isquemia/reperfusão.

PURPOSE: The main aim of this study was to determine the influence of ischemic preconditioning (IPC) on rat liver cirrhosis. METHODS: Cirrhosis was induced in Wistar rats by occlusion of the hepatic duct. The animals were divided into four groups of six animals each: non-cirrhotic group (simulated operation only), cirrhotic control group (simulated operation in cirrhotic rats), I/R group (40-minute ischemia without IPC), and IPC group (cirrhotic rats with ischemia, previously submitted to IPC). The IPC procedure consisted of partial hepatic ischemia for five minutes, followed by 10 minutes of reperfusion. In the case of the IPC group, the animals were submitted to liver ischemia for 40 minutes after the preconditioning procedure, followed by 2 hours of reperfusion. Blood samples were collected for measurement of serum aminotransferases (ALT and AST). The respiratory control ratio (RCR), the mitochondrial membrane potential (MMP), and malondialdehyde (MDA) values in the hepatic tissue were analyzed. Nonparametric statistical analysis was used and a value of p<0.05 was considered statistically significant. RESULTS: Ischemia did not induce significant increase in ALT and AST levels. MDA values were significantly higher in cirrhotic animals. MMP did not significantly change in cirrhosis and liver ischemia. Mitochondrial RCR decreased in liver cirrhosis, accentuated upon liver ischemia, and did not significantly change with IPC. CONCLUSION: Ischemic preconditioning does not protect the liver from hepatic injury induced by the ischemia/ reperfusion process.

OBJETIVO: Este estudo foi realizado com o objetivo de verificar o efeito do extrato aquoso da Hyptis pectinata na regeneração hepática bem como nos níveis das enzimas séricas (AST, ALT e gama-GT) após hepatectomia parcial de 67% em ratos. MÉTODOS: AST, ALT e gama-GT, foram determinadas pelo método cinético utilizando um espectrofotômetro (Modelo E2250-CELM). A regeneração hepática foi avaliada por imunohistoquímica (PCNA). RESULTADOS: O pré-tratamento oral de 100 mg/kg foi realizado durante 4 dias e causou aumento na regeneração hepática O pré-tratamento oral com 200 mg/kg diminuiu significativamente os níveis de AST quando comparado com o grupo submetido ao pré-tratamento com água destilada. As demais enzimas avaliadas não apresentaram diferenças quando comparadas entre os grupos estudados. CONCLUSÃO: O presente estudo mostra que o extrato aquoso da Hyptis pectinata, numa concentração de 100 mg/kg possui alguma atividade biológica estimulando a regeneração hepática e causando também um leve efeito hepatoprotetor numa concentração de 200 mg/kg.

PURPOSE: This study was carried out to assess the effects of the aqueous extract of Hyptis pectinata leaves on liver regeneration and on serum enzymes (AST, ALT and gamma-GT) after 67% partial hepatectomy in rats. METHODS: AST, ALT and gamma-GT, were determined by conventional procedures using a spectrophotometer (Model E2250-CELM). Liver regeneration was evaluated by immunohistochemical staining for proliferating cell nuclear antigen (PCNA). RESULTS:Oral pretreatment during 4 days at 100 mg/kg increased liver regeneration index. At 200 mg/kg, AST level was statistically decreased in comparison to the group submited to distilled water administration. The other enzymes assessed disclosed no difference when all groups were compared. CONCLUSION: The present study shows that the aqueous extract of Hyptis pectinata leaves contains some biological active principles that stimulate liver regeneration at 100 mg/kg and cause slight hepatic protection at 200 mg/kg.

OBJETIVO: A atividade plasmática da colinesterase (CHE) e a função mitocondrial do fígado expressa pela RCR- razão de controle respiratório mitocondrial foram estudadas durante a isquemia/reperfusão hepáticas. MÉTODOS: Dezesseis cães adultos sem raça definida (oito machos e oito fêmeas) foram submetidos a isquemia normotérmica por pinçamento do pedículo hepático e da veia cava inferior infra-hepática por 2 horas, seguida de 15 e 60 minutos de reperfusão.A CHE e a RCR foram avaliadas após 60 e 120 minutos de isquemia e após 15 e 60 minutos de reperfusão. RESULTADOS: Os níveis de CHE diminuíram significativamente na isquemia e reperfusão.A RCR diminuiu após 120 minutos de isquemia retornando a níveis semelhantes ao controle após a reperfusão. CONCLUSÃO: A CHE foi sensível para indicar a lesão isquêmica, sugerindo irreversibilidade da lesão. Já a RCR foi mais sensível no sentido de detectar a reversibilidade da lesão isquêmica após a reperfusão.

PURPOSE: The plasmatic activity of the cholinesterase (CHE) and the liver mitochondrial function, expressed by the ratio of respiratory control (RCR), were studied during normothermic ischemia. METHODS: Sixteen adult mongrels, eight females and eight males were submitted to ischemia by clamping of the hepatic artery, portal vein and infrahepatic inferior vena cava, infra-hepatic, for two h, follwed by reperfusion for 1 h. The CHE and the mitochondrial function were evaluated at 60 and 120 min. of ischemia and at 15 and 60 minutes of reperfusion. RESULTS: The CHE decreased, significantly, during ischemia and in reperfusion. The RCR was decreased at 120 min. of ischemia, returning to the initial values on reperfusion. CONCLUSION: In this study, the CHE was a sensitive indicator of ischemic injury , suggesting irreversibility of ischemia injury. The RCR, by other side, showed a greater sensibility than the CHE in detection sense, during the studied period, the reversibility of the hepatic ischemic injury.