ACG Clinical Guideline: disorders of the hepatic and mesenteric circulation

Disorders of the mesenteric, portal, and hepatic veins and mesenteric and hepatic arteries have important clinical consequences and may lead to acute liver failure, chronic liver disease, noncirrhotic portal hypertension, cirrhosis, and hepatocellular carcinoma. Although literature in the field of vascular liver disorders is scant, these disorders are common in clinical practice, and general practitioners, gastroenterologists, and hepatologists may benefit from expert guidance and recommendations for management of these conditions. These guidelines represent the official practice recommendations of the American College of Gastroenterology. Key concept statements based on author expert opinion and review of literature and specific recommendations based on PICO/GRADE analysis have been developed to aid in the management of vascular liver disorders. These recommendations and guidelines should be tailored to individual patients and circumstances in routine clinical practice.

Melatonin protects the liver and erythrocytes against oxidative stress in cirrhotic rats / Melatonina protege o fígado e eritrócitos do estresse oxidativo em ratos cirróticos

CONTEXT: Cirrhosis is a progressive chronic hepatopathy which constitutes an irreversible stage of liver dysfunction. OBJECTIVES: To evaluate the oxidative stress in the blood of cirrhotic rats treated with the antioxidant melatonin. METHODS: Cirrhosis was induced through inhalation of carbon tetrachloride. Liver integrity was evaluated by measuring serum enzymes, oxidative damage measured by lipoperoxidation, and antioxidant enzyme activity in erythrocytes. Lipoperoxidation, total nitrates, collagen, and histology by picrosirius staining were evaluated in the livers of these animals (n = 15), which were divided in three groups: control, carbon tetrachloride, and carbon tetrachloride + melatonin. Melatonin (20 mg/kg) was administered intraperitoneal from week 10 of carbon tetrachloride inhalation. In order to shorten the cirrhosis induction time, phenobarbital (0.3 g/L) was added to the animals' drinking water. RESULTS: A significant impairment in the liver integrity of melatonin-treated animals as compared to cirrhotic animals was observed. In rat erythrocytes and liver, lipoperoxidation was significantly increased in the cirrhotic rats as compared to controls, as measured through thiobarbituric acid reactive substances, and significantly decreased in melatonin-treated animals as compared to cirrhotic ones. In blood, a decrease in superoxide dismutase and glutathione peroxidase enzymes was detected in the cirrhotic group as compared to the control group, with increased superoxide dismutase activity when melatonin was administered. A reduction in the levels of total nitrates was detected in the hepatic tissue of the animals in the carbon tetrachloride group as compared to the control group and an increase of these levels in the carbon tetrachloride + melatonin group. As for hepatic collagen, we found a significant increase in the carbon tetrachloride group as compared to the controls and a regression of these values in the treated group. ...

CONTEXTO: A cirrose é uma hepatopatia crônica e progressiva que constitui estágio irreversível de disfunção hepática. É associada a alterações na circulação sistêmica. OBJETIVOS: Avaliar o estresse oxidativo no sangue de ratos cirróticos e tratados com antioxidante melatonina. MÉTODOS: A cirrose foi induzida através da inalação de tetracloreto de carbono. Foram avaliadas as provas de integridade hepática através das medidas das enzimas séricas, o dano oxidativo medido pela lipoperoxidação e a atividade das enzimas antioxidantes no eritrócito. No fígado desses animais, foram avaliados a lipoperoxidação, os nitratos totais, colágeno e histologia através de picrosíruis. Os animais (n = 15) foram divididos em três grupos experimentais: controle, tetracloreto de carbono e tetracloreto de carbono + melatonina. A melatonina foi administrada por via intraperitonial após a 10ª semana de inalação na concentração de 20 mg/kg. Com o objetivo de abreviar o tempo de indução, foi administrado para todos animais, fenobarbital na água de beber na concentração de 0,3 g/L. RESULTADOS: Observou-se redução significativa nas provas de integridade hepática nos animais tratados com melatonina, em relação aos animais cirróticos. Nos eritrócitos e fígados dos ratos, foi observado aumento significativo da lipoperoxidação nos ratos cirróticos em comparação com os controles, através da medida das substâncias que reagem ao ácido tiobarbitúrico, e redução nos animais tratados com melatonina. No sangue, observou-se diminuição dos valores das enzimas superóxido dismutase e glutationa peroxidase do grupo cirrótico em comparação ao grupo controle, elevando a atividade da superóxido dismutase quando administrada melatonina. Na avaliação dos nitratos totais, no tecido hepático, observou-se redução dos valores nos animais do grupo tetracloreto de carbono em comparação ao grupo CO e um aumento desses valores nos ratos do grupo tratado com melatonina. Na medida do colágeno ...