Recent reports in the literature suggest that oral contraceptive steroid therapy may be implicated in the development of benign hepatic adenomas in women. Since estrogens and progestins are known to affect liver function, we studied effects of chronic administration of the oral contraceptive agents mestranol and norethindrone on various indices of hepatic integrity. Several hepatic mixed function oxidase activities were measured: benzo(a)pyrene hydroxylase, epoxide hydrase, aniline hydroxylase (Appendix II) and aminopyrlne N-demethylase (Appendix II). In addition, benzo(a)pyrene hydroxylase activity in lung tissue was measured. As an indication of whether metabolites of the contraceptive steroids were bound to liver macromolecules, irreversible binding of [³H]-benzopyrene was measured. Hepatic histopathology (light microscopy using hematoxylin and eosin stain and oil red 0 stain) was carried out to determine if functional alterations correlated with pathological changes in the liver. Comparisons were also made between ethanol treated and non-ethanol treated groups to determine if contraceptive steroid-associated hepatotoxiclty was enhanced by or would enhance, the hepatotoxiclty of ethanol administration. Female and male Wistar rats were pair-fed a nutritional liquid diet, Sustacal[sup R] (Mead Johnson) to which was added either sucrose or ethanol as 40% of calories. Oral contraceptive steroids were administered daily in the liquid, diet in the following doses: mestranol, 0.6 mg/kg per day, alone or in combination with norethindrone, 5.0 mg/kg per day. Initial short-term studies showed that the ethanol plus Sustacal[sup R] diet generally caused enzyme induction compared to the plain Sustacal[sup R] diet or the sucrose plus Sustacal[sup R] diet in animals treated for up to 6 weeks. Animals that were administered the contraceptive steroids for a similar time period also demonstrated hepatic microsomal enzyme induction. Enzyme activity in animals that received ethanol plus the contraceptive steroids was increased above that seen for each agent alone. Chronic studies showed that ethanol administration for 6 months produced hepatotoxiclty in both male and female rats. Hepatotoxiclty was observed functionally as decreased hepatic benzo(a)pyrene hydroxylase activity and histopathologically as increased fat accumulation in zone 3 of the liver lobules. It was found that administration of the contraceptive steroids to female rats tended to protect against ethanol-associated hepatotoxiclty. The protective effect was observed functionally as maintenance of control levels of hepatic benzo(a)pyrene hydroxylase activity and morphologically as lesser amounts of fat accumulation ln the liver. That is, there tended to be a correlation between the level of hepatic benzo(a)pyrene hydroxylase activity and histological fat accumulation as an indication of ethanol-associated hepatotoxiclty. A Sustacal associated phenomenon was evident in all animals in which hlstopathology was carried out. The "Sustacal effect" was observed, as mlcrodroplet fat accumulation ln zone 1 of the liver lobule. Contraceptive steroid treated females showed the least "Sustacal effect". Microsomal enzyme activity did not appear to be affected by the "Sustacal effect". It was concluded that the contraceptive steroids administered did not increase ethanol hepatotoxicity. Instead, it appeared that female sex steroids tended to attenuate ethanol-assoclated hepatotoxicity. There was no evidence to suggest that the oral contraceptive steroids were directly associated with overt hepatotoxicity. / Medicine, Faculty of / Anesthesiology, Pharmacology and Therapeutics, Department of / Graduate

INTRODUÇÃO: O tamanho ideal do fígado varia entre 0,8% a 4% do peso do receptor (graft to body weight ratio - GBWR). Em crianças com menos de 10 kg submetidas a transplante hepático com doador vivo encontramos frequentemente uma situação denominada large-for-size, que ocorre ao se implantar um enxerto com peso maior que 4% do peso corpóreo do receptor. A lesão de isquemia/reperfusão (LIR) é uma resposta inflamatória mediada pelas células de Kupffer, principais responsáveis pela liberação de espécies reativas de oxigênio no parênquima hepático. Além disso, a célula de Kupffer libera citocinas pró-inflamatórias como TNF-alfa, IL-1 e IL-6 que recrutam polimorfonucleares sistêmicos e linfócitos T-CD4+ perpetuando a lesão mesmo após o fluxo sanguíneo estar restabelecido. O hipofluxo portal pode piorar a LIR na situação large-for-size. Desta forma, um shunt mesentérico-cava tentando direcionar o fluxo para a veia porta poderia ser benéfico nesta situação. MÉTODOS: Dezesseis porcos LandraceLargewhite pesando entre 17 - 38 kg foram submetidos a transplante de fígado. Foram distribuídos em três grupos: controle (CTRL), large-for-size (LFS) e shunt (SHUNT). Foi aferido o fluxo venoso portal, arterial hepático e colhido material para estudo histológico e biomolecular uma hora após a reperfusão. A relação entre o fluxo venoso portal do receptor para o fluxo venoso portal doador (rFVP) foi utilizada para se correlacionar com a gravidade da isquemia/reperfusão. Foram realizadas biópsias uma hora após o transplante para microscopia óptica e TUNEL além de quantificar a expressão dos genes da iNOS, eNOS, IL-6, BAX e BCL, c-fos/c-jun, ICAM e TNF-?. RESULTADOS: O GBWR foi maior nos grupos LFS e SHUNT (3,45 vs. 5,06 e 6,03; p=0,009). Quando comparamos isoladamente receptores e doadores por grupo houve diferença no fluxo portal somente nos grupos LFS (890 ± 203 mL / min vs. 458 ± 119 mL / min, p=0.0034) e SHUNT (1003 ± 5,3 mL/min vs. 495 ± 277 mL/min; p=0,0031). A rFVP foi próxima de 1 no grupo CTRL e significativamente maior que nos grupos LFS e SHUNT (p=0,03). O fluxo arterial hepático foi significativamente menor no grupo SHUNT (62,16 ± 31 mL / min) quando comparado com grupo CTRL (140.4 ± 53.88 mL / min) e LFS (142 ± 55.41 mL / min), p=0,02. A IL-6 e BAX foram menos expressas no grupo CTRL (p=0,05 e p=0,002). Houve uma relação linear entre a expressão dos genes BAX, TNF-alfa e eNOS com a rFVP (p=0,02; p=0,02 e p=0,009 respectivamente). Na avaliação histológica observou-se índice de isquemia e reperfusão semelhante entre os grupos CTRL e SHUNT mas menor em relação ao LFS, 3, 3,5 e 7 respectivamente (p=0,04). CONCLUSÕES: O transplante large-for-size acarreta hipofluxo portal relativo, e isto pode estar relacionado a um maior dano hepatocitário com acentuação da lesão de isquemia-reperfusão. A presença de um shunt entre a veia cava inferior e a veia mesentérica superior não conseguiu aumentar o influxo de sangue para o fígado de maneira persistente e pode estar implicado na diminuição do fluxo arterial hepático. No entanto, o aumento temporário do influxo portal pode estar relacionado a atenuação de algumas características da LIR no transplante large-for-size / INTRODUCTION: The optimum size of the liver graft for transplantation varies between 0.8% and 4% of the weight of the recipient (graft to body weight ratio - GBWR). In children with less than 10 kg who undergo liver transplantation with living donor a disorder called large-for-size (LFS) often occurs, when a graft weighing more than 4% of body weight of the recipient is implanted. Ischemia / reperfusion injury (IRI) is an inflammatory response mediated by Kupffer cells, mainly responsible for the release of reactive oxygen species in the liver parenchyma. In addition, Kupffer cells releases proinflammatory cytokines such as TNF-alfa, IL-1 and IL-6 that recruit systemic polymorphonuclear cells and T-CD4 + perpetuating this injury even after the blood flow is restored. Low portal flow may worsen IRI in LFS situation. So, a mesocaval shunt directing the flow to portal vein should be beneficial in this condition. METHODS: Sixteen Landrace/Largewhite pigs weighing approximately 20 kg (17-38 kg) underwent liver transplantation. They were divided into three groups: control (CTRL), large-for-size (LFS) and shunt (SHUNT). Portal venous flow was measured and liver and blood collected for histological and biomolecular study one hour after reperfusion. The relationship between the portal venous flow from the recipient to the donor portal venous flow (rFVP) was used to establish correlations with the parameters of ischemia and reperfusion. Biopsies were performed one hour after transplant to assess ischemia/reperfusion injury, TUNEL and quantify the following genes expression: iNOS, eNOS, IL-6, BAX and BCL c-fos / c-jun, ICAM, and TNF-alfa. RESULTS: GBWR was higher in groups LFS and SHUNT than CTRL (3.45 vs. 5.06 and 6.03; p=0.009). When compared separately by group recipients and donors difference in portal flow was observed only in LFS groups (890 ± 203 mL / min vs. 458 ± 119 mL / min, p=0.0034) and SHUNT (1003 ± 5.3 mL / min vs. 495 ± 277 mL / min, p=0.0031). rFVP was close to 1 in the CTRL group and significantly higher than the LFS and SHUNT groups (p= 0.03). Hepatic artery blood flow was significantly lower in SHUNT group (62.16 ± 31 mL / min) compared with CTRL group (140.4 ± 53.88 mL / min) and LFS (142 ± 55.41 mL / min), p= 0.02. IL-6 and BAX were expressed less in the CTRL group (p=0.05 and p=0.002). There was a linear relationship between the BAX, TNF-alfa and eNOS with rFVP (p=0.02, p=0.02 and p=0.009 respectively). Histological evaluation showed similar ischemia-reperfusion index between CTRL and SHUNT groups but lower values in compare to LFS group, 3, 3.5 and 7 respectively (p=0.04). CONCLUSIONS: The largefor-size liver transplantation leads to a relative low portal venous flow and this can be related to greater hepatocyte damage with accentuation of ischemia-reperfusion injury. The presence of a shunt between the inferior vena cava and the superior mesenteric vein could not increase the inflow of blood to the liver persistently and may be implicated in decreased hepatic artery blood flow. However, the temporary increase in portal inflow may be related to mitigation of some characteristics of IRI in large-for-size liver transplantation

INTRODUÇÃO: O tamanho ideal do fígado varia entre 0,8% a 4% do peso do receptor (graft to body weight ratio - GBWR). Em crianças com menos de 10 kg submetidas a transplante hepático com doador vivo encontramos frequentemente uma situação denominada large-for-size, que ocorre ao se implantar um enxerto com peso maior que 4% do peso corpóreo do receptor. A lesão de isquemia/reperfusão (LIR) é uma resposta inflamatória mediada pelas células de Kupffer, principais responsáveis pela liberação de espécies reativas de oxigênio no parênquima hepático. Além disso, a célula de Kupffer libera citocinas pró-inflamatórias como TNF-alfa, IL-1 e IL-6 que recrutam polimorfonucleares sistêmicos e linfócitos T-CD4+ perpetuando a lesão mesmo após o fluxo sanguíneo estar restabelecido. O hipofluxo portal pode piorar a LIR na situação large-for-size. Desta forma, um shunt mesentérico-cava tentando direcionar o fluxo para a veia porta poderia ser benéfico nesta situação. MÉTODOS: Dezesseis porcos LandraceLargewhite pesando entre 17 - 38 kg foram submetidos a transplante de fígado. Foram distribuídos em três grupos: controle (CTRL), large-for-size (LFS) e shunt (SHUNT). Foi aferido o fluxo venoso portal, arterial hepático e colhido material para estudo histológico e biomolecular uma hora após a reperfusão. A relação entre o fluxo venoso portal do receptor para o fluxo venoso portal doador (rFVP) foi utilizada para se correlacionar com a gravidade da isquemia/reperfusão. Foram realizadas biópsias uma hora após o transplante para microscopia óptica e TUNEL além de quantificar a expressão dos genes da iNOS, eNOS, IL-6, BAX e BCL, c-fos/c-jun, ICAM e TNF-?. RESULTADOS: O GBWR foi maior nos grupos LFS e SHUNT (3,45 vs. 5,06 e 6,03; p=0,009). Quando comparamos isoladamente receptores e doadores por grupo houve diferença no fluxo portal somente nos grupos LFS (890 ± 203 mL / min vs. 458 ± 119 mL / min, p=0.0034) e SHUNT (1003 ± 5,3 mL/min vs. 495 ± 277 mL/min; p=0,0031). A rFVP foi próxima de 1 no grupo CTRL e significativamente maior que nos grupos LFS e SHUNT (p=0,03). O fluxo arterial hepático foi significativamente menor no grupo SHUNT (62,16 ± 31 mL / min) quando comparado com grupo CTRL (140.4 ± 53.88 mL / min) e LFS (142 ± 55.41 mL / min), p=0,02. A IL-6 e BAX foram menos expressas no grupo CTRL (p=0,05 e p=0,002). Houve uma relação linear entre a expressão dos genes BAX, TNF-alfa e eNOS com a rFVP (p=0,02; p=0,02 e p=0,009 respectivamente). Na avaliação histológica observou-se índice de isquemia e reperfusão semelhante entre os grupos CTRL e SHUNT mas menor em relação ao LFS, 3, 3,5 e 7 respectivamente (p=0,04). CONCLUSÕES: O transplante large-for-size acarreta hipofluxo portal relativo, e isto pode estar relacionado a um maior dano hepatocitário com acentuação da lesão de isquemia-reperfusão. A presença de um shunt entre a veia cava inferior e a veia mesentérica superior não conseguiu aumentar o influxo de sangue para o fígado de maneira persistente e pode estar implicado na diminuição do fluxo arterial hepático. No entanto, o aumento temporário do influxo portal pode estar relacionado a atenuação de algumas características da LIR no transplante large-for-size / INTRODUCTION: The optimum size of the liver graft for transplantation varies between 0.8% and 4% of the weight of the recipient (graft to body weight ratio - GBWR). In children with less than 10 kg who undergo liver transplantation with living donor a disorder called large-for-size (LFS) often occurs, when a graft weighing more than 4% of body weight of the recipient is implanted. Ischemia / reperfusion injury (IRI) is an inflammatory response mediated by Kupffer cells, mainly responsible for the release of reactive oxygen species in the liver parenchyma. In addition, Kupffer cells releases proinflammatory cytokines such as TNF-alfa, IL-1 and IL-6 that recruit systemic polymorphonuclear cells and T-CD4 + perpetuating this injury even after the blood flow is restored. Low portal flow may worsen IRI in LFS situation. So, a mesocaval shunt directing the flow to portal vein should be beneficial in this condition. METHODS: Sixteen Landrace/Largewhite pigs weighing approximately 20 kg (17-38 kg) underwent liver transplantation. They were divided into three groups: control (CTRL), large-for-size (LFS) and shunt (SHUNT). Portal venous flow was measured and liver and blood collected for histological and biomolecular study one hour after reperfusion. The relationship between the portal venous flow from the recipient to the donor portal venous flow (rFVP) was used to establish correlations with the parameters of ischemia and reperfusion. Biopsies were performed one hour after transplant to assess ischemia/reperfusion injury, TUNEL and quantify the following genes expression: iNOS, eNOS, IL-6, BAX and BCL c-fos / c-jun, ICAM, and TNF-alfa. RESULTS: GBWR was higher in groups LFS and SHUNT than CTRL (3.45 vs. 5.06 and 6.03; p=0.009). When compared separately by group recipients and donors difference in portal flow was observed only in LFS groups (890 ± 203 mL / min vs. 458 ± 119 mL / min, p=0.0034) and SHUNT (1003 ± 5.3 mL / min vs. 495 ± 277 mL / min, p=0.0031). rFVP was close to 1 in the CTRL group and significantly higher than the LFS and SHUNT groups (p= 0.03). Hepatic artery blood flow was significantly lower in SHUNT group (62.16 ± 31 mL / min) compared with CTRL group (140.4 ± 53.88 mL / min) and LFS (142 ± 55.41 mL / min), p= 0.02. IL-6 and BAX were expressed less in the CTRL group (p=0.05 and p=0.002). There was a linear relationship between the BAX, TNF-alfa and eNOS with rFVP (p=0.02, p=0.02 and p=0.009 respectively). Histological evaluation showed similar ischemia-reperfusion index between CTRL and SHUNT groups but lower values in compare to LFS group, 3, 3.5 and 7 respectively (p=0.04). CONCLUSIONS: The largefor-size liver transplantation leads to a relative low portal venous flow and this can be related to greater hepatocyte damage with accentuation of ischemia-reperfusion injury. The presence of a shunt between the inferior vena cava and the superior mesenteric vein could not increase the inflow of blood to the liver persistently and may be implicated in decreased hepatic artery blood flow. However, the temporary increase in portal inflow may be related to mitigation of some characteristics of IRI in large-for-size liver transplantation