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Ability of S-Adenosyl-L-Methionine to Ameliorate Lipoprotein-Induced Membrane Lipid Abnormalities and Cellular Dysfunctions in Human Liver Disease. ACTA ACUST UNITED AC 2012. [DOI: 10.1007/bf03258361] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Ghali-Ghoul R, Tahseldar-Roumieh R, Sabra R. Effect of chronic administration of sildenafil on sodium retention and on the hemodynamic complications associated with liver cirrhosis in the rat. Eur J Pharmacol 2007; 572:49-56. [PMID: 17610866 DOI: 10.1016/j.ejphar.2007.05.068] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2007] [Accepted: 05/24/2007] [Indexed: 01/26/2023]
Abstract
Previous studies demonstrated increased phosphodiesterase-5 (PDE5) activity and expression in the kidneys of rats with liver cirrhosis. Acute intravenous administration of PDE5 inhibitors enhanced sodium excretion in these rats. The aim of the present study was to examine the effects of chronic administration of sildenafil on renal sodium handling and hemodynamics in rats with liver cirrhosis. Male Sprague-Dawley rats underwent bile-duct ligation and excision or sham operation and were housed in metabolic cages throughout the study. Body weight, food intake, water intake and urine volume were measured daily, and plasma samples were obtained twice weekly. Fourteen days following surgery sildenafil or its vehicle (dimethylsulfoxide) were administered (20 mg/kg subcutaneously 3 times/day). Two weeks later, systemic hemodynamics were measured under general anesthesia. Sildenafil enhanced the systemic vasodilatation associated with liver cirrhosis and reduced the arterial pressure. There was no reduction in the glomerular filtration rate, however. Despite these hemodynamic changes, sildenafil prevented the decrease in sodium excretion observed in the bile-duct-ligated group receiving vehicle and markedly increased fractional sodium excretion relative to the other groups. These results suggest that chronic sildenafil administration may help prevent or ameliorate sodium retention in cirrhosis, but that hemodynamic adverse effects may ensue.
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Affiliation(s)
- Rana Ghali-Ghoul
- Department of Pharmacology and Therapeutics, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
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Tahseldar-Roumieh R, Ghali-Ghoul R, Lugnier C, Sabra R. Effect of phosphodiesterase 5 inhibitor on alteration in vascular smooth muscle sensitivity and renal function in rats with liver cirrhosis. Am J Physiol Heart Circ Physiol 2006; 290:H481-8. [PMID: 16373593 DOI: 10.1152/ajpheart.00507.2005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Previous studies suggested that increased activity of phosphodiesterase (PDE)5 in the kidneys of cirrhotic rats contributes to sodium retention. This study examined the role of PDE5 in the changes in vascular reactivity, hemodynamics, and sodium excretion in rats with liver cirrhosis. Four weeks after bile duct ligation (BDL) or sham operation (SO), in vitro reactivity of aortic rings to various agents and in vivo effects of a PDE5-selective inhibitor [1,3-dimethyl-6-(2-propoxy-5-methanesulfonylamidophenyl)pyrazolo[3,4d]-pyrimidin-4-(5H)-one, DMPPO] were studied. The vasodilator responses to nitroglycerin and S-nitroso-N-acetyl-penicillamine (SNAP) in phenylephrine-precontracted rings without endothelium were attenuated in BDL compared with SO rats. Pretreatment with DMPPO (0.1 microM) enhanced these responses and eliminated the differences between the two groups. Vasodilation to DMPPO itself was also less in BDL rats. The responses to phenylephrine were attenuated in endothelium-rich aorta from BDL relative to SO rats, but they were similar in endothelium-denuded aorta and remained similar despite preincubation with SNAP (0.1 microM) alone or with SNAP and DMPPO. In vivo, BDL rats were vasodilated relative to SO rats; DMPPO (5 mg/kg i.v.) decreased arterial pressure and vascular resistance in both groups equally and caused significant increase in sodium excretion in BDL rats only. In conclusion, the results are in accordance with a possible increase in PDE5 activity in aorta and kidney of cirrhotic rats that results in reduced responses to NO donors and contributes to the increase in sodium retention. PDE5 inhibitors may ameliorate sodium retention in cirrhosis but may worsen vasodilation. Examining the effect of PDE5 inhibitors after chronic administration will be more revealing.
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Affiliation(s)
- Rima Tahseldar-Roumieh
- Dept. of Pharmacology and Therapeutics, Faculty of Medicine, American Univ. of Beirut, Beirut, Lebanon
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Sabra R, Shuman S. Influence of phenobarbital on changes in Na(+) handling, hemodynamics and liver function due to partial portal vein ligation in rats. Eur J Pharmacol 2001; 413:287-94. [PMID: 11226405 DOI: 10.1016/s0014-2999(01)00770-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
This study examined the influence of phenobarbital, an inducer of hepatic enzymes, on Na(+) handling, hemodynamics and liver function (measured by the rate constant of elimination of aminopyrine in the aminopyrine breath test) after partial portal vein ligation. Rats were randomized to drink either phenobarbital + water or water only for 10 days and then underwent either sham operation or partial portal vein ligation. The aminopyrine rate constant of elimination and Na(+) balance were measured daily before and after surgery; after surgery, hemodynamic measurements were obtained daily in a subset of rats. Phenobarbital raised the baseline aminopyrine rate constant of elimination. Partial portal vein ligation, but not sham operation, caused equivalent reductions in the aminopyrine rate constant of elimination in phenobarbital- and water-treated groups, such that the aminopyrine rate constant of elimination remained higher in the former. Na(+) balance increased significantly in partial portal vein ligation + water, but not sham + water rats on day 1 and then decreased on days 2 and 3. In contrast, neither sham + phenobarbital nor partial portal vein ligation + phenobarbital rats had a significant increase in Na(+) balance. Partial portal vein ligation resulted in vasodilation on day 3 after surgery in the water-treated rats, an effect that was prevented by treatment with phenobarbital. These results support previous suggestions that a reduction in liver function triggers renal Na(+) retention in this model. Vasodilation is not necessary for the latter effect, but also appears to be dependent on a reduction in liver function.
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Affiliation(s)
- R Sabra
- Department of Pharmacology and Therapeutics, Faculty of Medicine, American University of Beirut, P.O. Box 11-0236/37, Beirut, Lebanon.
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Jalink D, Urbanski SJ, Lee SS. Bilioenteric anastomosis reverses hyperkinetic circulation in bile duct-ligated cirrhotic rats. J Hepatol 1996; 25:924-31. [PMID: 9007722 DOI: 10.1016/s0168-8278(96)80298-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
BACKGROUND/AIMS The chronic bile duct-ligated rat is used to study hemodynamic changes in cirrhosis but suffers from total biliary obstruction and deep jaundice. The extent of reversibility of hemodynamics and histology following bile flow reconnection is controversial. We aimed to characterize the hemodynamics and histology of bile duct-ligated cirrhotic rats in which bile flow was reconnected by a Roux-en-y choledochojejunostomy. METHODS Operations created four groups: double sham (control), bile duct ligated, and two reconnected groups. Cardiac index and regional blood flows were measured by radioactive microspheres 4 weeks following the last operation in the first three groups and 8 weeks afterwards in the second reconnected group. Liver histology was assessed by a computer-aided scoring program. RESULTS Cardiac index, mean arterial pressure, and systemic vascular resistance in the reconnected groups were different from bile duct-ligated rats and returned to control values. Portal pressures in the reconnected groups (4-weeks, 10.0 +/- 0.5 and 8-week, 9.7 +/- 0.6 mmHg) were significantly lower than in bile-duct-ligated rats (13.7 +/- 0.6) but remained elevated compared to controls (7.0 +/- 0.3). Portal pressure in the reconnected rats was correlated with cardiac index and mesenteric blood flow, r = 0.66 and r = 0.45, respectively. Liver histology was improved in the reconnected rats, with decreased bile duct proliferation, fibrosis and apoptosis. CONCLUSIONS We conclude that many of the histological features of secondary biliary cirrhosis are reversible after bilioenteric anastomosis. Furthermore, the hyperdynamic circulation is also largely reversible and is related to the degree of portal hypertension.
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Affiliation(s)
- D Jalink
- Liver Unit, University of Calgary, Canada
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Murakami S, Ohno T, Bernardo JF, Pfeifer CA, Li T, Zhang Y, Dubey RK, Branch RA, Sabra R. Reduced liver function is the trigger for renal sodium retention following portal vein ligation in the rat. J Gastroenterol Hepatol 1996; 11:850-6. [PMID: 8889965 DOI: 10.1111/j.1440-1746.1996.tb00092.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Sodium retention along with peripheral vasodilation are features of prehepatic portal hypertension. In several models of experimental liver damage, sodium retention occurs only when hepatic function, measured by the aminopyrine breath test (ABT-k), falls below a critical threshold. The relationship between renal sodium handling, ABT-k and systemic and renal haemodynamics in partial portal vein ligated (PVL) rats was examined to test hypothesis that peripheral vasodilation was responsible for initiating sodium retention. Haemodynamic measurements were conducted early after surgery in portal hypertensive rats with and without sodium retention and in sham-operated controls. Compared with control, both PVL groups of rats had elevated portal pressure and lower peripheral vascular resistance (P < 0.05). Sodium retaining-PVL rats had both lower ABT-k (0.95 +/- 0.05 vs 1.38 +/- 0.06 x 10(-2)/min; P < 0.05) and higher sodium balance (1.38 +/- 0.09 vs 0.43 +/- 0.09 mmol/day; P < 0.05) than non-sodium retaining PVL rats. No differences in plasma renin activity or noradrenaline concentrations were observed. In a separate group of rats, hydralazine-induced pheripheral vasodilation did not induce sodium retention. These results suggest that the presence of peripheral vasodilation alone is not sufficient to trigger a sodium-retaining status. A factor, probably liver function-dependent, acting directly on renal tubules may be necessary for changes in renal sodium handling in this model.
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Affiliation(s)
- S Murakami
- Center for Clinical Pharmacology, University of Pittsburgh Medical Center, Pennsylvania 15213-2582, USA
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Abstract
A total of 29 patients with well-compensated alcoholic cirrhosis and 9 healthy control subjects of similar age and sex were studied to assess their response to a challenge of 2 L of normal saline infused over a 1 hr period. Patients with cirrhosis had an adequate effective arterial blood volume in the basal state as assessed by neurohumoral markers of vascular filling. They also had a lower renal vascular resistance (p = 0.048) and a higher glomerular filtration rate (p = 0.014) than the controls, indicating the presence of renal vasodilation. Both groups were in sodium balance, but the patients with cirrhosis had a higher filtered load of sodium, an increased proximal tubular reabsorption of sodium (p = 0.015) and a decreased fractional excretion of sodium (p < 0.001). The administration of a saline load was not accompanied by any significant changes in the renal circulation in the patients with cirrhosis. They were unable to suppress their proximal tubular reabsorption of sodium to the same extent as the controls (p = 0.012), so by the fourth hour a significant difference in the rate of urinary excretion of sodium was evident. In the patients with cirrhosis, glomerular filtration rate before and after the saline load correlated significantly with indocyanine green extraction (r = 0.65; p = 0.002), whereas the tubular handling of sodium was dependent on antipyrine clearance (r = 0.80; p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- F Wong
- Department of Gastroenterology, Alfred Hospital, Prahran, Victoria, Australia
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Abstract
Recent studies have suggested that the development of sodium retention in experimental cirrhosis in the rat occurs when hepatic function, measured by the aminopyrine breath test, decreases below a critical threshold. The present study evaluated the relationship between renal sodium handling and hepatic function and determined whether sodium retention occurs following partial portal vein ligation. Sodium balance, urine volume, creatinine clearance and the aminopyrine rate constant of elimination, on a constant sodium intake, were evaluated daily, from 1 day before surgery to 5 days after surgery, in both sham-operated (n = 6) and partially portal vein-ligated rats (n = 14). In the partially portal vein-ligated group, sodium retention occurred in 9 rats between 1 and 4 days after surgery, accompanied by a 45% reduction in the aminopyrine rate constant of elimination. Spontaneous natriuresis occurred within 5 days after surgery, and was associated with an increase in the aminopyrine rate constant of elimination from 0.94 +/- 0.07 x 10(-2) min-1 on the last day of sodium retention to 1.36 +/- 0.06 x 10(-2) min-1 on the day of diuresis (P < 0.05). In contrast, creatinine clearance did not change throughout the study. There was a negative curvilinear association between sodium balance and the aminopyrine rate constant of elimination (r = 0.70, P < 0.001). In the five rats without sodium retention, there was no change in the aminopyrine rate constant of elimination and creatinine clearance over the 5 days.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- T Ohno
- Center for Clinical Pharmacology, University of Pittsburgh School of Medicine, Pennsylvania 15261
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Decaux G, Prospert F, Namias B, Schlesser M, Soupart A. Raised urea clearance in cirrhotic patients with high uric acid clearance is related to low salt excretion. Gut 1992; 33:1105-8. [PMID: 1398236 PMCID: PMC1379451 DOI: 10.1136/gut.33.8.1105] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
In cirrhotic patients without renal failure, salt retention could result from a decreased effective intravascular volume or could be a primary event leading to increased intravascular volume. Clearance of urea and uric acid depend on an effective intravascular volume. In the syndrome of inappropriate secretion of antidiuretic hormone (SIADH)--a state of increased intravascular volume--uric acid clearance is increased and that of urea is increased only when salt excretion is low. The intravascular volume of 60 consecutive cirrhotic patients without renal failure was estimated indirectly by studying the relationship between fractional excretion of filtered (FE) sodium, urea, and uric acid. Forty five per cent had a high FE uric acid (> 12%), which could mean a high intravascular volume, and presented with an FE urea that was inversely correlated with FE sodium (r = 0, 62; p < 0.001) as in SIADH, while in the controls the FE urea was positively correlated with FE sodium (r = +0, 46; p < 0.01). In patients who had a normal FE uric acid and low FE sodium (< 0.2%), the FE urea was significantly lower (40 (13)%, n = 20) than in subjects with high FE uric acid and a low FE sodium (61 (9)%, n = 16, p < 0.001); this last group also presented with lower mean blood urea concentrations (3.1 (1.2) mmol/l and 4.0 (1.8) mmol/l; p < 0.05) and a lower supine renin activity (p < 0.01). As observed in the SIADH, cirrhotic patient with high FE uric acid have raised FE urea only when salt excretion is low. It is believed that the low salt excretion is not caused by a decrease in effective intravascular volume and that this is increased in cirrhotic patients with raised FE uric acid.
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Affiliation(s)
- G Decaux
- Department of Internal Medicine, University Hospital Erasme, Free University of Brussels, Belgium
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Krähenbühl S, Stucki J, Reichen J. Reduced activity of the electron transport chain in liver mitochondria isolated from rats with secondary biliary cirrhosis. Hepatology 1992; 15:1160-6. [PMID: 1592354 DOI: 10.1002/hep.1840150630] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Mitochondrial metabolism was studied in liver mitochondria isolated from rats with secondary biliary cirrhosis induced by bile duct ligation for 5 wk. State 3 oxidation rates were decreased in mitochondrial preparations from bile duct-ligated rats as compared with sham-operated control rats by 63% and 42% using beta-hydroxybutyrate and succinate as substrates, respectively. In contrast, when the substrate was ascorbate/N,N,N',N'-tetramethyl-p-phenylenediamine state 3 oxidation rates were not affected by bile duct ligation. Oxidation rates after uncoupling with dinitrophenol were decreased for both beta-hydroxybutyrate and succinate as substrates in mitochondria from bile duct-ligated rats. The phosphate potential was reduced in mitochondria from bile duct-ligated rats (12.5 +/- 0.5 vs. 13.6 +/- 0.2 kcal in control and bile duct-ligated rats, respectively; p less than 0.05). The inner mitochondrial membrane of liver mitochondria from rats with secondary biliary cirrhosis contained three times more cholesterol as compared with control rats, whereas the phospholipid composition was essentially unchanged. Mitochondrial protein content expressed per liver (calculated on the basis of activities of mitochondrial enzymes determined in liver homogenate and in isolated mitochondria) was increased by 50% in bile duct-ligated rats as compared with control rats. In conclusion, the function of the electron transport chain in liver mitochondria isolated from rats with secondary biliary cirrhosis is impaired. This decrease could be related to altered lipid composition of the inner mitochondrial membrane.
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Affiliation(s)
- S Krähenbühl
- Department of Clinical Pharmacology, University of Berne, Switzerland
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Increased Na(+)-dependent D-glucose transport and altered lipid composition in renal cortical brush-border membrane vesicles from bile duct-ligated rats. J Lipid Res 1992. [DOI: 10.1016/s0022-2275(20)41613-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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