anandamide and Liver-Cirrhosis

Cirrhosis is associated with marked cardiovascular disturbances. These include hyperdynamic circulation characterized by reduced peripheral vascular resistance and mean arterial pressure and increased cardiac output. Despite the baseline increase in cardiac output, ventricular responsiveness to stimuli is blunted. A number of cellular signaling pathways have been shown to contribute to these abnormalities, including central nervous system cardiovascular dysregulation and humoral factors such as nitric oxide. Endogenous and exogenous cannabinoids have significant cardiovascular effects. Recent evidence suggests that increased activity of the endocannabinoid system at multiple levels contributes to development of both cardiac and vascular changes in cirrhosis. This brief review surveys recent in vivo and in vitro findings in an attempt to highlight the areas of agreement and areas of controversy in the field. The endocannabinoid system affects key cardiovascular regulators, including the autonomic nervous system, cardiac muscle, and vascular smooth muscle. The interplay among these modes of action further complicates interpretation of the in vivo findings. The broad range of cardiovascular actions of endocannabinoids provides ample opportunities for pharmacological manipulation. At the same time, it increases the possibility of undesirable side effects, which need to be carefully evaluated in long-term studies.

Topics: Animals; Arachidonic Acids; Cannabinoid Receptor Modulators; Cardiovascular Diseases; Endocannabinoids; Humans; Liver Cirrhosis; Polyunsaturated Alkamides; Rats; Receptors, Cannabinoid; Splanchnic Circulation; TRPV Cation Channels

Cirrhosis is associated with blunted cardiovascular response to stimuli such as hemorrhage, but the mechanism remains unclear. We aimed to clarify the role of endocannabinoids in blunted hemorrhage response in cirrhotic rats.. Cirrhosis was induced by bile duct ligation (BDL). Hemodynamics were measured. Cannabinoid receptor-1 (CB1) antagonist, AM251, and macrophage inhibitor gadolinium chloride (GdCl3) were administered. Myocardial levels of anandamide (AEA) and 2-arachidonoyl glycerol (2-AG) were measured and resident monocytes and macrophages quantified by immunohistochemistry. Isolated cardiomyocyte contractility was measured before and after incubation with monocytes from BDL and sham controls.. Hemorrhage significantly decreased arterial pressure and left ventricular dP/dT. After hemorrhage, these changes quickly reversed in controls, but were severely prolonged in BDL rats. Chronic AM251 treatment restored this impaired response. AEA and 2-AG levels were increased in BDL hearts and further increased after hemorrhage. Sham hearts showed virtually no monocytes or macrophages before or after hemorrhage, whereas BDL hearts had significantly more white blood cells which further increased after hemorrhage. GdCl3 treatment significantly reduced cardiac endocannabinoid levels both at baseline and after hemorrhage. This treatment also restored cardiovascular response to hemorrhage in BDL rats but did not affect sham controls. Monocytes isolated from BDL rats more potently inhibited cardiomyocyte contractility than sham control monocytes.. The cirrhotic heart showed increased monocyte recruitment and endocannabinoid levels. CB1 blockade or GdCl3 treatment restored blunted cardiovascular response to hemorrhage. Endocannabinoids released by monocytes blunt cardiac response to hemorrhage. Preventing monocyte recruitment or blocking endocannabinoid signaling may improve cardiovascular homeostasis in cirrhosis.

Topics: Animals; Arachidonic Acids; Blood Pressure; Cardiac Output; Endocannabinoids; Gadolinium; Glycerides; Hemorrhage; Liver Cirrhosis; Macrophages; Male; Monocytes; Myocardial Contraction; Myocardium; Piperidines; Polyunsaturated Alkamides; Pyrazoles; Rats; Rats, Sprague-Dawley; Receptor, Cannabinoid, CB1; Ventricular Function, Left

1297C/T polymorphism of CYP4F2 gene was studied in 108 patients with chronic liver diseases. No significant correlation with predisposition to rapid liver cirrhosis was revealed without consideration for cirrhosis etiology (OR=0.93, 95% CI=0.28-2.99, p=0.885). In patients with viral cirrhosis, a tendency to association of 1297T allele genotypes with rapid cirrhosis development was found (OR=6.0, 95% CI=0.28-382.64, p=0.222). At the same time, CYP4F2 1297T allele was associated with mild (Child-Pugh class A-B) cirrhosis (OR=2.9, p=0.044).

Topics: Adolescent; Adult; Aged; Arachidonic Acids; Cannabinoid Receptor Agonists; Cytochrome P-450 Enzyme System; Cytochrome P450 Family 4; Endocannabinoids; Female; Gene Frequency; Genetic Predisposition to Disease; Genotype; Humans; Liver Cirrhosis; Male; Middle Aged; Polymorphism, Single Nucleotide; Polyunsaturated Alkamides; Young Adult

Endocannabinoids include anandamide (AEA) and 2-arachidonoylglycerol (2-AG). Endocannabinoid-related molecules like oleoyl-ethanolamine (OEA) and palmitoyl-ethanolamine (PEA) have also been identified. AEA contributes to the pathogenesis of cardiovascular alterations in experimental cirrhosis, but data on the endocannabinoid system in human cirrhosis are lacking. Thus, we aimed to assess whether circulating and hepatic endocannabinoids are upregulated in cirrhotic patients and whether their levels correlate with systemic haemodynamics and liver function.. The endocannabinoid levels were measured in peripheral and hepatic veins and liver tissue by isotope-dilution liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry. Systemic haemodynamics were assessed by the transthoracic electrical bioimpedance technique. Portal pressure was evaluated by hepatic venous pressure gradient.. Circulating AEA and, to a greater extent, PEA and OEA were significantly higher in cirrhotic patients than in controls. PEA and OEA were also increased in the cirrhotic liver tissue. AEA, OEA and PEA levels were significantly higher in peripheral than in the hepatic veins of cirrhotic patients, while the opposite occurred for 2-AG. Finally, circulating AEA, OEA and PEA correlated with parameters of liver function, such as serum bilirubin and international normalized ratio. No correlations were found with systemic haemodynamics.. The endocannabinoid system is upregulated in human cirrhosis. Peripheral AEA is increased in patients with a high model of end-stage liver disease score and may reflect the extent of liver dysfunction. In contrast, the 2-AG levels, the other major endocannabinoid, are not affected by cirrhosis. The upregulation of the endocannabinoid-related molecules, OEA and PEA, is even greater than that of AEA, prompting pharmacological studies on these compounds.

Topics: Adult; Amides; Arachidonic Acids; Bilirubin; Biomarkers; Cannabinoid Receptor Modulators; Case-Control Studies; Chromatography, Liquid; Electric Impedance; Endocannabinoids; Ethanolamines; Female; Glycerides; Hemodynamics; Humans; International Normalized Ratio; Italy; Liver; Liver Cirrhosis; Liver Function Tests; Male; Mass Spectrometry; Middle Aged; Oleic Acids; Palmitic Acids; Polyunsaturated Alkamides; Radioisotope Dilution Technique; Severity of Illness Index; Up-Regulation

Topics: Amides; Arachidonic Acids; Biomarkers; Cannabinoid Receptor Modulators; Endocannabinoids; Ethanolamines; Glycerides; Hemodynamics; Humans; International Normalized Ratio; Liver; Liver Cirrhosis; Oleic Acids; Palmitic Acids; Polyunsaturated Alkamides; Severity of Illness Index; Up-Regulation

This study examined endogenous cannabinoid (ECB)-anandamide (AEA) and its cannabinoid receptors (CBR) in mice liver with the development of schistosoma japonicum. Mice were infected with schistosoma by means of pasting the cercaria onto their abdomens. Liver fibrosis was pathologically confirmed nine weeks after the infection. High performance liquid chromatography (HPLC) was employed to determine the concentration of AEA in the plasma of mice. Immunofluorescence was used to detect the expression of CBR1 and CBR2 in liver tissue. Morphological examination showed typical pathological changes, with worm tubercles of schistosoma deposited in the liver tissue, fibrosis around the worm tubercles and infiltration or soakage of inflammatory cells. Also, CBR1 and CBR2 were present in hepatocytes and hepatic sinusoids of the two groups, but they were obviously enhanced in the schistosoma-infected mice. However, the average optical density of CBR1 in the negative control and fibrosis group was 13.28+/-7.32 and 30.55+/-7.78, and CBR2 were 28.13+/-6.42 and 52.29+/-4.24 (P<0.05). The levels of AEA in the fibrosis group were significantly increased as compared with those of the control group. The concentrations of AEA were (0.37+/-0.07) and (5.67+/-1.34) ng/mL (P<0.05). It is concluded that the expression of endocannabinoids AEA and its cannabinoid receptor CBR were significantly increased in schistosoma-infected mice. Endogenous endocannabinoids may be involved in the development of schistosoma-induced liver fibrosis.

Topics: Animals; Arachidonic Acids; Cannabinoid Receptor Modulators; Endocannabinoids; Liver Cirrhosis; Male; Mice; Polyunsaturated Alkamides; Random Allocation; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2; Schistosomiasis japonica

Cannabinoids have been reported to participate in the pathogenesis of peripheral vasodilatation in cirrhosis. However, their roles in increased intrahepatic resistance (IHR) in cirrhotic livers are unknown. We aimed to investigate the effects of cannabinoids in the hepatic microcirculation of cirrhotic rats produced by bile duct ligation. In isolated liver perfusion, portal perfusion pressure (PPP) and the production of eicosanoids in the perfusate were measured. In addition, various hepatic protein levels [cyclooxygenase (COX) isoform and 5-lipoxygenase (5-LOX)] were also determined. Finally, concentration-response curves for PPP and the corresponding production of eicosanoids in response to anandamide (1.44 x 10(-10)-1.44 x 10(-3) M) after indomethacin (COX inhibitor), piriprost (5-LOX inhibitor), or furegrelate (thromboxane A(2) synthase inhibitor) preincubation were obtained. The study showed that cirrhotic livers had significantly higher levels of PPP, COX-2 and 5-LOX protein expression, and production of thromboxane B(2) (TXB(2)) and cysteinyl leukotrienes (Cys-LTs) than normal livers. Anandamide induced a dose-dependent increase in PPP in both normal and cirrhotic livers. The anandamide-induced increase in PPP was found concomitantly with a significant increase in TXB(2) and Cys-LT production in the perfusate. In response to anandamide administration, cirrhotic livers exhibited a significantly greater increase in IHR and production of TXB(2) and Cys-LTs than normal livers. Indomethacin and furegrelate, but not piriprost, significantly ameliorated the anandamide-induced increase in IHR in cirrhotic livers. In conclusion, anandamide plays, in part, an important role in increased IHR of cirrhotic livers. The anandamide-induced increase in IHR in cirrhotic livers may be mediated by increased COX-derived eicosanoid (mainly thromboxane A(2)) production.

Topics: 6-Ketoprostaglandin F1 alpha; Animals; Arachidonate 5-Lipoxygenase; Arachidonic Acids; Blood Pressure; Blotting, Western; Cyclooxygenase 1; Cyclooxygenase 2; Cyclooxygenase Inhibitors; Cysteine; Eicosanoids; Endocannabinoids; In Vitro Techniques; Leukotrienes; Lipoxygenase Inhibitors; Liver; Liver Circulation; Liver Cirrhosis; Male; Microcirculation; Perfusion; Polyunsaturated Alkamides; Rats; Rats, Sprague-Dawley; Thromboxane B2

The endogenous cannabinoid anandamide (AEA) is a lipid mediator that blocks proliferation and induces apoptosis in many cell types. Although AEA levels are elevated in liver fibrosis, its role in fibrogenesis remains unclear. This study investigated effects of AEA in primary hepatic stellate cells (HSCs). Anandamide blocked HSC proliferation at concentrations of 1 to 10 micromol/L but did not affect HSC proliferation or activation at nanomolar concentrations. At higher concentrations (25-100 micromol/L), AEA rapidly and dose-dependently induced cell death in primary culture-activated and in vivo-activated HSCs, with over 70% cell death after 4 hours at 25 micromol/L. In contrast to treatment with Fas ligand or gliotoxin, AEA-mediated death was caspase independent and showed typical features of necrosis such as rapid adenosine triphosphate depletion and propidium iodide uptake. Anandamide-induced reactive oxygen species (ROS) formation, and an increase in intracellular Ca(2+). Pretreatment with the antioxidant glutathione or Ca(2+)-chelation attenuated AEA-induced cell death. Although the putative endocannabinoid receptors CB1, CB2, and VR1 were expressed in HSCs, specific receptor blockade failed to block cell death. Depletion of membrane cholesterol by methyl-beta-cyclodextrin inhibited AEA binding, blocked ROS formation and intracellular Ca(2+)-increase, and prevented cell death. In primary hepatocytes, AEA showed significantly lower binding and failed to induce cell death even after prolonged treatment. In conclusion, AEA efficiently induces necrosis in activated HSCs, an effect that depends on membrane cholesterol and a subsequent increase in intracellular Ca(2+) and ROS. The anti-proliferative effects and the selective killing of HSCs, but not hepatocytes, indicate that AEA may be used as a potential anti-fibrogenic tool.

Topics: Animals; Apoptosis; Arachidonic Acids; Calcium; Cannabinoid Receptor Modulators; Cell Death; Cells, Cultured; Cholesterol; Endocannabinoids; Hepatocytes; Humans; JNK Mitogen-Activated Protein Kinases; Liver Cirrhosis; Male; Necrosis; NF-kappa B; Polyunsaturated Alkamides; Rats; Reactive Oxygen Species; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2; Receptors, Drug; Tumor Necrosis Factor-alpha

Endocannabinoids may participate in the homeostasis of arterial pressure. Recently, anandamide, the most extensively studied endocannabinoid, has been proposed as a key mediator in the peripheral arterial vasodilation of cirrhosis.. To determine if circulating levels of anandamide are related to the extent of the peripheral arterial vasodilation, the severity of portal hypertension and the degree of liver and renal dysfunction of patients with cirrhosis.. Plasma levels of anandamide and several systemic, portal and renal hemodynamic parameters were determined in 18 patients with cirrhosis and eight healthy subjects (control group).. Plasma levels of anandamide were elevated in patients compared to the control group (P<0.05), nevertheless, no differences between patients with ascites and well-compensated patients were found. There was no correlation between anandamide concentration and arterial pressure, cardiac output and systemic vascular resistance, Child-Pugh's score, portal pressure, renal vascular resistance, plasma renin activity or plasma aldosterone concentration.. Circulating levels of anandamide are increased in cirrhotic patients. However, this elevation was unrelated to the extent of arterial vasodilation, the severity of portal hypertension or the degree of hepatic and renal dysfunction. Although a local hormonal action cannot be excluded, our results do not support a relevant contribution of this system in the hemodynamic disturbance of cirrhosis.

Topics: Arachidonic Acids; Cannabinoid Receptor Modulators; Endocannabinoids; Female; Glomerular Filtration Rate; Humans; Hypertension, Portal; Liver Cirrhosis; Male; Middle Aged; Polyunsaturated Alkamides; Stroke Volume; Vascular Resistance

Advanced cirrhosis is associated with generalized vasodilation of unknown origin, which contributes to mortality. Cirrhotic patients are endotoxemic, and activation of vascular cannabinoid CB1 receptors has been implicated in endotoxin-induced hypotension. Here we show that rats with biliary cirrhosis have low blood pressure, which is elevated by the CB1 receptor antagonist SR141716A. The low blood pressure of rats with CCl4-induced cirrhosis was similarly reversed by SR141716A, which also reduced the elevated mesenteric blood flow and portal pressure. Monocytes from cirrhotic but not control patients or rats elicited SR141716A-sensitive hypotension in normal recipient rats and showed significantly elevated levels of anandamide. Compared with non-cirrhotic controls, in cirrhotic human livers there was a three-fold increase in CB1 receptors on isolated vascular endothelial cells. These results implicate anandamide and vascular CB1 receptors in the vasodilated state in advanced cirrhosis and indicate a novel approach for its management.

Topics: Animals; Arachidonic Acids; Cannabinoid Receptor Modulators; Chromatography, High Pressure Liquid; Endocannabinoids; Endothelium, Vascular; Hypotension; Liver Cirrhosis; Male; Mass Spectrometry; Monocytes; Polyunsaturated Alkamides; Rats; Rats, Sprague-Dawley; Receptors, Cannabinoid; Receptors, Drug; Vasodilation

Topics: Animals; Arachidonic Acids; Cannabinoids; Endocannabinoids; Humans; Liver; Liver Cirrhosis; Liver Cirrhosis, Experimental; Piperidines; Polyunsaturated Alkamides; Portal Pressure; Pyrazoles; Rats; Receptors, Cannabinoid; Receptors, Drug; Rimonabant; Vasodilation