Immunohistochemical analysis of growth factor expression and localization in gastric coronary vein of cirrhotic patients

Restructuring of the vascular bed in response to hemodynamic disturbances in portal hypertension

In recent years, defined progress has been made in understanding the mechanisms of hemodynamic disturbances occurring in liver cirrhosis, which are based on portal hypertension. In addition to pathophysiological disorders related to endothelial dysfunction, it was revealed: There is the restructuring of the vasculature, which includes vascular remodeling and angiogenesis. In spite of the fact that these changes are the compensatory-adaptive response to the deteriorating conditions of blood circulation, taken together, they contribute to the development and progression of portal hypertension causing severe complications such as bleeding from esophageal varices. Disruption of systemic and organ hemodynamics and the formation of portosystemic collaterals in portal hypertension commence with neovascularization and splanchnic vasodilation due to the hypoxia of the small intestine mucosa. In this regard, the goal of comprehensive treatment may be to influence on the chemokines, proinflammatory cytokines, and angiogenic factors (vascular endothelial growth factor, placental growth factor, platelet-derived growth factor and others) that lead to the development of these disorders. This review is to describe the mechanisms of restructuring of the vascular bed in response to hemodynamic disturbances in portal hypertension. Development of pathogenetic methods, which allow correcting portal hypertension, will improve the efficiency of conservative therapy aimed at prevention and treatment of its inherent complications.

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Research progress of vasculopathy in portal hypertension

Portal hypertension, one of the vascular diseases, not only has lesions in liver, but also changes in vascular structures and functions of extrahepatic portal system, systemic system and pulmonary circulation. The pathological changes of vasculopathy in portal hypertension include remodeling of arterialized visceral veins, intimal injury of visceral veins and destruction of contractile structure in visceral arterial wall. The mechanisms of vasculopathy in portal hypertension may be attributed to the changes of hemodynamics in portal system, immune response, gene modulation, vasoactive substances, and intrahepatic blood flow resistance. Portal hypertension can cause visceral hyperdynamic circulation, and the development and progression of visceral vasculopathy, while visceral vasculopathy can promote the development and progression of portal hypertension and visceral hyperdynamic circulation in turn. The aforementioned three factors interact in the pathogenesis of hepatic cirrhosis-induced portal hypertension and are involved in hemorrhage due to varicose vein rupture.

Endothelial dysfunction in cirrhosis and portal hypertension

Portal hypertension (PHT) is a common clinical syndrome associated with chronic liver diseases; it is characterized by a pathological increase in portal pressure. Pharmacotherapy for PHT is aimed at reducing both intrahepatic vascular tone and elevated splanchnic blood flow. Due to the altered hemodynamic profile in PHT, dramatic changes in mechanical forces, both pressure and flow, may play a pivotal role in controlling endothelial and vascular smooth muscle cell signaling, structure, and function in cirrhotics. Nitric oxide, prostacyclin, endothelial-derived contracting factors, and endothelial-derived hyperpolarizing factor are powerful vasoactive substances released from the endothelium in response to both humoral and mechanical stimuli that can profoundly affect both the function and structure of the underlying vascular smooth muscle. This review will examine the contributory role of hormonal- and mechanical force-induced changes in endothelial function and signaling and the consequence of these changes on the structural and functional response of the underlying vascular smooth muscle. It will focus on the pivotal role of hormonal and mechanical force-induced endothelial release of vasoactive substances in dictating the reactivity of the underlying vascular smooth muscle, i.e., whether hyporeactive or hyperreactive, and will examine the extent to which these substances may exert a protective and/or detrimental influence on the structure of the underlying vascular smooth muscle in both a normal hemodynamic environment and following hemodynamic perturbations typical of PHT and cirrhosis. Finally, it will discuss the intracellular processes that regulate the release/expression of these vasoactive substances and that control the transformation of this normally protective cell to one that may promote the development of vasculopathy in PHT.

Clinical implication of VEGF serum levels in cirrhotic patients with or without portal hypertension

AIM: To determine whether serum vascular endothelial growth factor (VEGF) levels correlates with the severity of liver cirrhosis and whether portal hypertension impacts on the expression of serum VEGF protein.

METHODS: Fifty-three patients (mean age 56 ± 2 years) with HCV (n = 26), HBV (n = 13), and cryptogenic liver cirrhosis (n = 14) (Child-Pugh-s class A: 24, B: 19 and C: 12) and normal renal function constitute the patient population, who were all diagnosed by clinical, histological and radiological findings. Six healthy people and six patients with acute hepatitis served as controls. Severity of liver disease was evaluated by the CP score. Serum levels of IGF-1 and VEGF were measured by radioimmunoassay and ELISA, respectively. Portal hypertension was assessed using pulsed Doppler ultrasound.

RESULTS: The mean serum VEGF levels in all cirrhotic patients (73 ± 58) were significantly lower than those of healthy controls (360 ± 217, P < 0.01) and acute hepatitis (1123 ± 1261, P < 0.01) respectively. No significant difference in median serum VEGF levels were noted among the different Child-Pugh-s classes (class A: median, 49.4 ng/L, range, 21-260 ng/L, Class B: median 59.9 ng/L; range 21-92, and Class C: median 69; range 20-247 ng/L). A significant correlation was noted between serum VEGF and two accurate parameters of portal hypertension: portal blood flow velocity (r = 06) and spleen size (r = 0.55). No correlation was found between VEGF serum levels and serum albumin, IGF-1, platelets count and aminotrasnferases (r = 0.2, r = 0.1, r = 0.2 and r = 0.2, respectively).

CONCLUSION: Circulating VEGF level in patients with liver cirrhosis could not serve as an indicator of the progression of chronic liver disease but rather, they may reflect increased portal hypertension or decreased hepatic regenerative activity or the combination of both.