Tetrahydrobiopterin (BH4) is an essential cofactor in NO synthesis by endothelial nitric oxide synthase (eNOS) enzymes. It has been previously suggested that reduced intrahepatic BH4 results in a decrease in intrahepatic NO and contributes to increased hepatic vascular resistance and portal pressure in animal models of cirrhosis. The main aim of the present study was to evaluate the relationship between BH4 and portal hypertension (PHT). One hundred ninety-three consecutive patients with chronic liver disease were included in the study. Liver biopsy, measurement of BH4 and hepatic venous pressure gradient (HVPG) were performed. Hepatic fibrosis was classified using the Laennec fibrosis scoring system. BH4 levels were determined in homogenized liver tissues of patients using a high performance liquid chromatography (HPLC) system. Statistical analysis was performed to evaluate the relationship between BH4 and HVPG, grade of hepatic fibrosis, clinical stage of cirrhosis, Child-Pugh class. A positive relationship between HVPG and hepatic fibrosis grade, clinical stage of cirrhosis and Child-Pugh class was observed. However, the BH4 level showed no significant correlation with HVPG or clinical features of cirrhosis. BH4 concentration in liver tissue has little relation to the severity of portal hypertension in patients with chronic liver disease.
Adult ; Aged ; Biopterin/*analogs & derivatives/analysis ; *Chromatography, High Pressure Liquid ; Chronic Disease ; Elasticity Imaging Techniques ; Female ; Hepatic Veins/physiology ; Humans ; Hypertension, Portal/complications/*diagnosis/metabolism ; Liver/pathology ; Liver Cirrhosis/ultrasonography ; Liver Diseases/complications/*diagnosis/metabolism ; Male ; Middle Aged ; Nitric Oxide/metabolism ; Portal Pressure ; Regression Analysis ; Severity of Illness Index

Previous studies reported that oxaliplatin is associated with sinusoidal obstruction syndrome. However few reports on oxaliplatin induced liver fibrosis are found in the literature. Furthermore pathogenesis of liver fibrosis is not well known. We report a case of 45-yr-old Korean man in whom liver fibrosis with splenomegaly developed after 12 cycles of oxaliplatin based adjuvant chemotherapy for colon cancer (T4N2M0). Thorough history taking and serological examination revealed no evidence of chronic liver disease. Restaging CT scans demonstrated a good response to chemotherapy. Five month after chemotherapy, he underwent right hepatectomy due to isolated metastatic lesion. The liver parenchyma showed diffuse sinusoidal dilatation and centrilobular vein fibrosis with necrosis without steatosis. We could conclude that splenomegaly was due to perisinusoidal liver fibrosis and liver cell necrosis induced portal hypertension by oxaliplatin. In addition, to investigate the pathogenesis of liver fibrosis, immunohistochemical stains such as CD31 and alpha-smooth muscle actin (alpha-SMA) were conducted with control group. The immunohistochemical stains for CD31 and alpha-SMA were positive along the sinusoidal space in the patient, while negative in the control group. Chemotherapy with oxaliplatin induces liver fibrosis which should be kept in mind as a serious complication.
Actins/metabolism ; Antigens, CD31/metabolism ; Antineoplastic Combined Chemotherapy Protocols/*therapeutic use ; Camptothecin/*analogs & derivatives/therapeutic use ; Chemotherapy, Adjuvant ; Colonic Neoplasms/*drug therapy ; Fluorouracil/therapeutic use ; Humans ; Hypertension, Portal/etiology ; Immunohistochemistry ; Leucovorin/therapeutic use ; Liver Cirrhosis/*diagnosis/etiology/pathology ; Liver Neoplasms/secondary/surgery ; Male ; Middle Aged ; Organoplatinum Compounds/*administration & dosage/adverse effects/therapeutic use ; Splenomegaly/*diagnosis/etiology ; Thrombocytopenia/etiology ; Tomography, X-Ray Computed

The lymphatic system is part of the circulatory system and plays a key role in normal vascular function. Its failure plays a crucial role in the development and maintenance of various diseases including liver diseases. Lymphangiogenesis (the growth of lymphatic vessels) and changes in the properties of lymphatic vessels are associated with pathogenesis of tumor metastases, ascites formation, liver fibrosis/cirrhosis and portal hypertension. Despite its significant role in liver diseases and its importance as a potential therapeutic target for those diseases, the lymphatic vascular system of the liver is poorly understood. Therefore, how the lymphatic vascular system in general and lymphangiogenesis in particular are mechanistically related to the pathogenesis and maintenance of liver diseases are largely unknown. This article summarizes: 1) the lymphatic vascular system; 2) its role in liver tumors, liver fibrosis/cirrhosis and portal hypertension; and 3) its role in ascites formation.
Ascites/*etiology ; Humans ; Hypertension, Portal/complications/pathology ; Liver Cirrhosis/complications/pathology ; Liver Diseases/complications/*pathology ; Liver Neoplasms/complications/pathology ; Lymphangiogenesis ; Lymphatic Vessels/metabolism/physiopathology

Because of the anatomical position and its unique vascular system, the liver is susceptible to the exposure to the microbial products from the gut. Although large amount of microbes colonize in the gut, translocation of the microbes or microbial products into the liver and systemic circulation is prevented by gut epithelial barrier function and cleansing and detoxifying functions of the liver in healthy subjects. However, when the intestinal barrier function is disrupted, large amount of bacterial products can enter into the liver and systemic circulation and induce inflammation through their receptors. Nowadays, there have been various reports suggesting the role of gut flora and bacterial translocation in the pathogenesis of chronic liver disease and portal hypertension. This review summarizes the current knowledge about bacterial translocation and its contribution to the pathogenesis of chronic liver diseases and portal hypertension.
Antigens, CD14/metabolism ; Bacterial Translocation ; Gastrointestinal Tract/*microbiology ; Humans ; Hypertension, Portal/metabolism/*pathology ; Liver/metabolism/*microbiology ; Liver Cirrhosis/metabolism/*pathology ; Receptors, Cytoplasmic and Nuclear/metabolism ; Toll-Like Receptors/metabolism

Adult ; Arsenic Poisoning ; pathology ; Chronic Disease ; Hemosiderin ; metabolism ; Hemosiderosis ; metabolism ; pathology ; Humans ; Hypertension, Portal ; chemically induced ; metabolism ; pathology ; Liver Cirrhosis ; chemically induced ; metabolism ; pathology ; Male ; Pancytopenia ; chemically induced ; metabolism ; pathology ; Splenomegaly ; chemically induced ; metabolism ; pathology

Portal hypertensive gastropathy (PHG) is a term used to define the endoscopic findings of gastric mucosa with a characteristic mosaic-like pattern with or without red spots, and a common finding in patients with portal hypertension. These endoscopic findings correspond to dilated mucosal capillaries without inflammation. The pathogenesis of PHG in not well known, but portal hypertension and some humoral factors seem to be crucial factors for its development. Pharmacological (e.g. propranolol), or interventional radiological (such as transjugular intrahepatic portosystemic shunt) procedures may be useful in preventing re-bleeding from PHG. The classic features of gastric antral vascular ectasia (GAVE) syndrome include red, often haemorrhagic lesions predominantly located in the gastric antrum which can result in significant blood loss. Although the pathogenesis of GAVE is not clearly defined, it seems to be a separate disease entity from PHG, because GAVE generally does not respond to a reduction of portal pressures. Endoscopic ablation (such as argon plasma coagulation) is the first-line treatment of choice. This review will focus on the incidence, clinical importance, etiology, pathophysiology, and treatment of PHG and GAVE syndrome in the setting of portal hypertension.
Esophageal and Gastric Varices/*diagnosis/etiology/therapy ; Gastric Antral Vascular Ectasia/*diagnosis/etiology/therapy ; Gastric Mucosa/metabolism/pathology ; Humans ; Hypertension, Portal/*complications ; Portasystemic Shunt, Transjugular Intrahepatic ; Vasodilator Agents/therapeutic use

Current understanding of the pathophysiology of portal hypertension has resulted in therapeutic approaches aimed at correcting the increased splanchnic blood flow and some of which have been already used in clinical practice. Recently new perspectives opened and erstwhile paradigm has been changed to focus on increased resistance to portal blood flow and the formation of portosystemic collateralization. Several studies revealed the clear-cut mechanisms of hepatic endothelial dysfunction and abnormal angiogenesis contributing to the development of portal hypertension. Thus the modulations of hyperdynamic circulation or angiogenesis seem to be valuable therapeutic targets. In the current review update, we discuss the multidisciplinary management of modulating hepatic vascular resistance and abnormal angiogenesis associated with portal hypertension. However, these new pharmacological approaches are still under investigation and widescale clinical application are needed to develop effective strategies.
Adrenergic beta-Antagonists/therapeutic use ; Bone Marrow Transplantation ; Cyclooxygenase Inhibitors/therapeutic use ; Humans ; Hydroxymethylglutaryl-CoA Reductase Inhibitors/therapeutic use ; Hypertension, Portal/*therapy ; Neovascularization, Pathologic/drug therapy ; Nitric Oxide/metabolism ; Vascular Resistance ; Vasoconstrictor Agents/therapeutic use

Portal hypertension (PHT) is associated with changes in the intrahepatic, systemic and portosystemic collateral circulations. Alteration in vasoreactivity (vasodilation and vasoconstriction) plays a central role in the pathogenesis of PHT by contributing to increased intrahepatic resistance, hyperdynamic circulation and the expansion of the collateral circulation. PHT is also importantly characterized by changes in vascular structure; termed vascular remodeling, which is an adaptive response of the vessel wall that occurs in response to chronic changes in the environment such as shear stress. Angiogenesis, the sprouting of new blood vessels, also occurs in PHT, especially in the expansion of the portosystemic collateral circulation. These complementary processes of vasoreactivity, vascular remodeling and angiogenesis represent important targets in the research for the treatment of portal hypertension.
Collateral Circulation/physiology ; Endothelial Cells/metabolism ; Hepatic Stellate Cells/metabolism ; Humans ; Hypertension, Portal/*etiology ; Liver Circulation/physiology ; Vascular Resistance

Portal hypertension (PHT) is associated with hemodynamic changes in intrahepatic, systemic, and portosystemic collateral circulation. Increased intrahepatic resistance and hyperdynamic circulatory alterations with expansion of collateral circulation play a central role in the pathogenesis of PHT. PHT is also characterized by changes in vascular structure, termed vascular remodeling, which is an adaptive response of the vessel wall that occurs in response to chronic changes in the environment such as shear stress. Angiogenesis, the formation of new blood vessels, also occurs with PHT related in particular to the expansion of portosystemic collateral circulation. The complementary processes of vasoreactivity, vascular remodeling, and angiogenesis represent important targets for the treatment of portal hypertension. Systemic and splanchnic vasodilatation can induce hyperdynamic circulation which is related with multi-organ failure such as hepatorenal syndrome and cirrhotic cadiomyopathy.
Collateral Circulation/physiology ; Endothelial Cells/metabolism ; Hemodynamics ; Hepatic Stellate Cells/metabolism ; Hypertension, Portal/*etiology ; Liver Circulation/physiology ; Liver Cirrhosis/*etiology ; Splanchnic Circulation/physiology

Hyperdynamic circulation in patients with liver cirrhosis is characterized by increased cardiac output and heart rate, and decreased systemic vascular resistance with low arterial blood pressure and currently focused on understanding the pathogenesis because of possibility of developing novel treatment modality. Basically, these hemodynamic alternations arise from portal hypertension. Portosystemic collaterals develop to counterbalance the increased intrahepatic vascular resistance to portal blood flow and induce an increase in venous return to heart. Increased shear stress in vascular endothelial cell related high blood flow by portosystemic shunting contributes to this up-regulation of eNOS resulting in NO overproduction. Additionally, bypassing through portosystemic collaterals and escaping degradation of over-produced circulating vasodilators in the diseased liver can promote the peripheral arterial vasodilation. Vasodilation of the systemic and splanchnic circulations lead to a reduced systemic vascular resistance, and increased cardiac output and splanchnic blood flow. Furthermore, neurohumoral vasoconstrictive systems including systemic nervous system, rennin angiotensin aldosterone system, and vasopressin are intensively activated secondary to vasodilation. However, hyperdynamic circulation would be more aggravated by the activated vasoconstrictive systems. With the progression of the cirrhotic process, hyperdynamic alternations can be more profound due to hyporesponsiveness to vasoconstrictors and increased shunt formation in conjunction with autonomic neuropathy. Eventually, splanchnic arterial vasodilation results in an increase portal venous inflow, maintaining the elevated portal venous pressure. Hyperdynamic circulation is intimately involved in portal hypertension with liver cirrhosis, therefore it is reasonable to have an interest in complete understanding of the pathogenensis of hyperdynamic circulation to develop novel treatment modality.
Blood Circulation/*physiology ; Blood Flow Velocity/physiology ; Humans ; Hypertension, Portal/etiology/*physiopathology ; Liver/blood supply/physiopathology ; Liver Cirrhosis/drug therapy/etiology/*physiopathology ; Nitric Oxide/metabolism ; Nitric Oxide Synthase Type III/metabolism ; Vasodilation