Temporal relationship between hyperaldosteronism, sodium retention and ascites formation in rats with experimental cirrhosis

To investigate the role of aldosterone in sodium retention and ascites in cirrhosis, the urinary sodium excretion, sodium balance and urinary excretion of aldosterone-18-glucuronide (UAldV) were serially measured in 11 rats undergoing cirrhosis induction with carbon tetrachloride (CT) and phenobarbital (CT rats) and in 10 control rats which received phenobarbital. All CT rats developed ascites, seven within the ninth week after starting the program and four within the 10th week. One week before the onset of ascites, CT rats and control rats were different with respect to sodium excretion (1.41 +/- 0.15 vs. 1.82 +/- 0.1 mEq per day), sodium balance (0.57 +/- 0.12 vs. 0.20 +/- 0.09 mEq per day) and UAldV (67.8 +/- 9.5 vs. 25.7 +/- 1.7 ng per day). These differences were more pronounced within the week in which ascites was detected in CT rats. Before these 2 weeks, both groups did not differ with respect to these parameters. In the 132 urine samples obtained in CT rats, there was a correlation between sodium excretion and UAldV (r = -0.53; p less than 0.001). Twenty-one additional CT rats were divided into two groups. Eleven animals were given spironolactone (20 mg per day s.c. in olive oil) from the 6th week, and 10 only received olive oil. Thirteen weeks after starting the program, all rats not treated with spironolactone had sodium retention and ascites (in five rats, ascites appeared within the ninth week and in five within the tenth week); this occurred in only one animal treated with spironolactone.(ABSTRACT TRUNCATED AT 250 WORDS)     

Sodium handling in patients with well compensated cirrhosis is dependent on the severity of liver disease and portal pressure

BACKGROUND AND AIMS: To test the contribution of portal pressure gradient (PPG) and neurohumoral factors to sodium handling in cirrhotic patients without ascites, by comparing preascitic cirrhotic patients with patients with transjugular intrahepatic portosystemic stent shunt (TIPSS) and previous ascites. PATIENTS: Ten patients with TIPSS and 10 preascitic cirrhotic patients. METHODS: Changes in glomerular filtration, renal plasma flow, urinary sodium excretion (U(Na)V), and neurohumoral factors were measured before and for two hours after infusion of one litre of 0. 9% saline over one hour. RESULTS: Glomerular filtration rate and renal plasma flow were significantly higher in patients with TIPSS compared with preascitic cirrhotic patients. Following saline infusion both parameters increased significantly; this increase was significantly greater in patients with TIPSS. U(Na)V increased significantly in both groups following saline infusion. The increase in U(Na)V was significantly greater in the TIPSS group. Plasma renin activity and angiotensin II decreased significantly in both groups. Basal U(Na)V was independently correlated with angiotensin II concentration and PPG and the change in U(Na)V correlated with the PPG. CONCLUSIONS: Results suggest that patients with advanced liver disease and low portal pressure handle sodium as well as patients with compensated liver disease and high portal pressure. These results are consistent with the notion that in addition to peripheral vasodilatation and severity of liver disease, the severity of portal hypertension contributes to the abnormalities of sodium retention in cirrhosis.     

Influence of posture on haemodynamics, sodium and hormonal homeostasis in cirrhotic patients with and without ascites

BACKGROUND/AIMS: Previous studies in preascitic cirrhosis demonstrated sodium retention during upright posture and sodium hyperexcretion during bed-rest. In patients with ascites, sodium excretion and creatinine clearance decreased during upright posture. Head-down tilting (HDT) accentuated the natriuretic effect of bed-rest in short term studies. The aim of this study was to evaluate the effects of prolonged change in posture on sodium homeostasis and on haemodynamics in cirrhotic patients. METHODS: Eighteen cirrhotic patients (9 with, 9 without ascites), were studied during 12 h upright, supine and HDT position (-10 degrees). During each position, 12 h urine collections were performed and blood samples were obtained before and after change in position. Non-invasive systemic hemodynamic measurements were performed. RESULTS: There was no significant difference between HDT and supine position in both ascitic and preascitic groups for urinary volume, fractional sodium excretion, creatinine clearance, urinary and plasma hormones and hemodynamics. Urinary volume (in supine and HDT) and fractional sodium excretion (in supine) were significantly higher and urinary noradrenaline and plasma renin (in supine and HDT) significantly lower in the preascitic group compared with the ascitic patients. Cardiac output and heart rate decreased after 12 h supine and HDT, suggesting a deactivation of sympatic nervous system and catecholamines. CONCLUSION: Our results demonstrate that prolonged HDT had no advantage over normal bed-rest in both patient groups. Possibly, a short-term beneficial effect of HDT was lost after several hours.     

Abnormal sympathetic and renal response to sodium restriction in compensated cirrhosis

It has been proposed that in liver cirrhosis portal hypertension causes splanchnic vasodilation and this induces blood volume expansion to maintain blood pressure. The current study was designed to explore the homeostatic response to sodium restriction, a maneuver aiming to contract blood volume, in compensated cirrhosis. Mean blood pressure, sympathetic nervous activity, and proximal sodium reabsorption were evaluated in 16 healthy control and 21 nonazotemic cirrhotic patients (11 without ascites and 10 with ascites) under two experimental conditions: after 4 days on a free sodium diet (basal condition) and after 4 days on a restricted sodium diet (40 mmol/day). No differences were observed in basal conditions in the above parameters between control and cirrhotic patients without ascites. However, cirrhotic patients with ascites showed lower basal values of mean blood pressure and higher basal levels of both plasma norepinephrine and fractional proximal sodium reabsorption than controls. Neither control nor cirrhotic patients with ascites showed significant changes in the measured parameters after sodium restriction. In contrast, in nonascitic patients, this maneuver induced an elevation in plasma norepinephrine concentration (164.4 +/- 24.6 vs. 270.1 +/- 24.9 pg/mL; mean +/- SEM; P less than 0.005) and in fractional proximal sodium reabsorption (86.4 +/- 2.1 vs. 91.8% +/- 0.5%; P less than 0.01). In addition, the nonascitic cirrhotic patients became hypotensive compared with controls (80.9 +/- 1.6 vs. 88.5 +/- 4.8 mm Hg; P less than 0.05) when subjected to the low-sodium diet. In patients without ascites, under conditions of sodium restriction, the decrease in mean arterial pressure correlated inversely with the increase in plasma norepinephrine concentration (r = -0.713; P less than 0.05), whereas the levels of plasma norepinephrine correlated directly with fractional proximal sodium reabsorption (r = 0.893; P less than 0.01). These findings suggest that ineffective circulatory volume is detected in nonascitic cirrhotic patients only under conditions of sodium restriction, but it is always present in cirrhotic patients with ascites, irrespectively of the amount of sodium in the diet. These results are compatible with the existence of fixed arterial vasodilation in cirrhosis.     

Increased natriuretic efficiency of furosemide in rats with carbon tetrachloride-induced cirrhosis

The authors examined the natriuretic efficiency of furosemide in rats with cirrhosis induced by carbon tetrachloride (CCl(4)). Rats were treated for 17 weeks with intraperitoneal injections of CCl(4) in groundnut oil twice a week throughout the study. Control rats were treated with vehicle (groundnut oil). Studies in metabolic cages showed that sodium retention was present from week 14. Renal clearance experiments were performed in chronically, instrumented conscious rats at the end of week 14 and at the termination of the study (end week 16) when ascites and hyponatremia were present. After 14 weeks, cirrhotic rats had sodium retention along with increased renal plasma flow, normal GFR, normal renal lithium handling, and a significantly increased diuretic (+41% vs. control) and natriuretic (+56% vs. control) response to a test dose furosemide (7.5 mg/kg b.w., intravenously). The natriuretic efficiency of furosemide, i.e., the natriuresis expressed relative to the furosemide excretion rate (triangle upU(Na)V/U(FUR)V) was increased by 51% versus control. After 17 weeks, ascites and hyponatremia had developed, and significant decreases in renal plasma flow (-33%), GFR (-30%), and fractional lithium excretion (-44%) were observed. At this stage urinary recovery of furosemide was significantly decreased and the diuretic (-27% vs. Control) and natriuretic (-38% vs. control) responses to furosemide were significantly impaired. However, the increased natriuretic efficiency of furosemide was still present (+34% vs. control). Together these results suggest that increased sodium reabsorption in the thick ascending limb of Henle's loop is involved in the renal sodium retention in cirrhosis in rats that eventually results in decompensation with the formation of ascites.     

Oral bile acids reduce bacterial overgrowth,bacterial translocation,and endotoxemia in cirrhotic rats

Experiments were performed to test whether conjugated bile acid administration would decrease bacterial overgrowth, bacterial translocation, and endotoxemia in ascitic cirrhotic rats. Cholylsarcosine, a deconjugation-dehydroxylation resistant and cholylglycine, a deconjugation-dehydroxylation susceptible bile acid were used. Rats with CCl(4)-induced cirrhosis and ascites were fed cholylsarcosine, cholylglycine (both at 70 mg/kg/d), or placebo for 2 weeks. Healthy rats, as controls, were treated similarly. In cirrhotic rats receiving placebo, bile secretion from an acute biliary fistula was lower than in healthy rats (27.2 +/- 6.5 vs. 53.0 +/- 3.1 microL/kg/min; mean +/- SE, P<.05). The administration of conjugated bile acids to cirrhotic rats normalized bile secretion (cholylsarcosine, 51.8 +/- 6.29; cholylglycine, 52.72 +/- 8.9 microL/kg/min). Total ileal bacterial content was 6-fold higher in ascitic cirrhotic rats than in healthy rats. Conjugated bile acid administration reduced bacterial content to normal levels. Bacterial translocation was less in cirrhotic animals receiving conjugated bile acids (cholylsarcosine, 33%; cholylglycine, 26%) than in animals receiving placebo (66%). Endotoxemia was decreased in cirrhotic rats by conjugated bile acid feeding (cholylsarcosine, 0.098 +/- 0.002; cholylglycine 0.101 +/- 0.007 EU/mL) compared with placebo (0.282 +/- 0.124, P <.001). Survival was greater in animals receiving conjugated bile acids (cholylsarcosine, 10/15; cholylglycine, 11/15; placebo, 5/15). In conclusion, the administration of conjugated bile acids to ascitic cirrhotic rats increased bile acid secretion, eliminated intestinal bacterial overgrowth, decreased bacterial translocation, decreased endotoxemia, and increased survival. Oral conjugated bile acids may be useful in preventing bacterial translocation, endotoxemia, and spontaneous bacterial perotonitis in cirrhotic patients.     

A lithium clearance study of sodium reabsorption at the proximal tubule in liver cirrhosis with ascites

Since the reabsorption of lithium occurs almost exclusively in the proximal tubule and is associated with that of sodium, the fractional excretion of lithium (FELit) ws examined in 18 patients with cirrhosis in order to examine the reabsorption rate of sodium at the proximal tubule. As expected, the fractional excretion of sodium (FENa) was significantly lower in cirrhotic patients with ascites (0.43 +/- 0.10%, mean +/- SEM) than in cirrhotic patients without ascites (0.75 +/- 0.14%, P less than 0.05) and healthy controls (0.82 +/- 0.17%, P less than 0.05). By contrast, there was no significant difference in FELit among cirrhotic patients with ascites (16.7 +/- 2.0%), cirrhotic patients without ascites (15.4 +/- 2.0%) and controls (17.4 +/- 1.5%). It is unlikely, therefore, that in cirrhotic patients with ascites, the impaired sodium excretion is solely caused by the abnormal sodium reabsorption capacity of the proximal tubule.     

Role of altered systemic hemodynamics in the blunted renal response to atrial natriuretic peptide in rats with cirrhosis and ascites

The natriuretic effect of pharmacological doses of atrial natriuretic peptide (ANP) is markedly reduced in cirrhosis with ascites. The current study, which includes two protocols, was carried out to investigate whether this phenomenon is related to the altered systemic hemodynamics present in cirrhosis. In protocol A, the administration of ANP (2.5 micrograms.kg-1 as a bolus followed by a constant infusion of 0.1 microgram.kg-1.min-1) to 10 rats with carbon tetrachloride-induced cirrhosis and ascites produced a significantly lower increase in diuresis (13.4 +/- 1.3 microliters/min) and natriuresis (2.3 +/- 0.3 mu Equiv/min) than in 10 control rats (56.3 +/- 1.4 microliters/min and 8.7 +/- 0.5 mu Equiv/min, respectively), indicating a renal resistance to the effect of ANP in this experimental model of cirrhosis. The reduction of arterial pressure induced by ANP was similar in both groups. However, since baseline mean arterial pressure was significantly lower in cirrhotic rats, the degree of hypotension during ANP infusion was also greater in this group of animals (82 +/- 3 vs. 109 +/- 2 mmHg). The aim of protocol B was to assess whether normalization of arterial pressure in cirrhotic rats increases the renal response to ANP. This protocol includes two groups of 10 rats with cirrhosis and ascites infused with a glucose solution containing norepinephrine (CT-NE rats) or angiotensin II (CT-AII rats) at doses to normalize arterial pressure and an additional control group of 10 cirrhotic rats with ascites receiving only glucose solution (CT rats). Angiotensin II, but not norepinephrine or glucose solution administration, was associated with a significant increase in urine volume and sodium excretion. During ANP infusion, CT rats showed a blunted diuretic and natriuretic response. In contrast, the ANP-induced increase in urine volume and sodium excretion observed in CT-NE (53.6 +/- 10.4 microliters/min and 9.3 +/- 2.2 mu Equiv/min) and CT-AII rats (98.3 +/- 11.6 microliters/min and 15.5 +/- 2.9 mu Equiv/m), was similar or even greater than that showed by the healthy rats of protocol A. The degree of hypotension during ANP administration was also similar (CT-NE, 104 +/- 2; CT-AII, 108 +/- 5 mmHg). These results suggest that the blunted response to pharmacological doses of ANP in cirrhosis with ascites is related to altered systemic hemodynamics of cirrhosis, which further deteriorates during the infusion of the peptide.     

Effect of WeiJia on carbon tetrachloride induced chronic liver injury

AIM:To study the effect of WeiJia on chronic liver injuryusing carbon tetrachloride(CCl_4)induced liver injuryanimal model.METHODS:Wistar rats weighing 180-220g were ran-domly divided into three groups:normal control group(Group A),CCl_4 induced liver injury control group(GroupB)and CCl_4 induction with WeiJia treatment group(GroupC).Each group consisted of 14 rats.Liver damage andfibrosis was induced by subcutaneous injection with 40?l_4 in olive oil at 3 mL/kg body weight twice a week foreight weeks for Groups B and C rats whereas olive oilwas used for Group A rats.Starting from the third week,Group C rats also received daily intraperitoneal injectionof WeiJia at a dose of 1.25 μg/kg body weight.Animalswere sacrificed at the fifth week(4 male,3 female),andeighth week(4 male,3 female)respectively.Degree offibrosis were measured and serological markers for liverfibrosis and function including hyaluronic acid(HA),typeIV collagen(CIV),γ-glutamyl transferase(γ-GT),alanineaminotransferase(ALT)and aspartate aminotransferase(AST)were determined.Alpha smooth muscle actin (α-SMA)and proliferating cell nuclear antigen(PCNA)immunohistochemistry were also performed.RESULTS:CCl_4 induction led to the damage of liver anddevelopment of fibrosis in Group B and Group C ratswhen compared to Group A rats.The treatment of WeiJiain Group C rats could reduce the fibrosis condition sig-nificantly compared to Group B rats.The effect could beobserved after three weeks of treatment and was moreobvious after eight weeks of treatment.Serum HA,CIV,ALT,AST and γ-GT levels after eight weeks of treatmentfor Group C rats were 58±22 μg/L(P<0.01),57±21 μg/L(P<0.01),47±10 U/L(P<0.01),139±13 U/L(P<0.05)and 52±21 U/L(P>0.05)respectively,similar to normalcontrol group(Group A),but significantly different fromCCl_4 induced liver injury control group(Group B).An in-crease in PCNA and decrease in α-SMA expression levelwas also observed.CONCLUSION:WeiJia could improve liver function andreduce liver fibrosis which might be through the inhibi-tion of stellate cell activity.     

Sodium homeostasis with chronic sodium loading in preascitic cirrhosis

BACKGROUND: Preascitic cirrhotic patients receiving 200 mmol of sodium daily for seven days remain in positive sodium balance. Thereafter, sodium handling is unknown. AIM: To assess renal sodium handling in preascitic cirrhosis on a high sodium diet for five weeks. METHODS: Sixteen biopsy proven preascitic cirrhotics were assessed at weekly intervals for five weeks on a diet of 200 mmol sodium/day using a daily weight diary and weekly 24 hour urinary sodium estimations. Fasting supine neurohormone levels were measured at baseline and weekly for five weeks while haemodynamics were measured at baseline and at five weeks. RESULTS: The daily diet of 200 mmol of sodium resulted in weight gain and a positive sodium balance for three weeks, associated with significant suppression of plasma renin activity and aldosterone levels, and a significant rise in plasma atrial natriuretic peptide levels (p<0.05). Patients' weights plateaued during week 4, associated with complete sodium balance and significant suppression of plasma noradrenaline levels (p<0.05). This was followed by a negative sodium balance and weight loss, and finally complete sodium balance, again despite a mean net gain of 2.3 (0.3) kg, associated with a return of plasma renin activity and aldosterone levels to within normal ranges. The lack of increase in central blood volume in addition to the persistent increase in plasma atrial natriuretic peptide levels indicated that residual volume expansion, consequent to persistent weight gain, was distributed on the venous side of the circulation. No free fluid was seen on repeat abdominal ultrasound after five weeks. CONCLUSION: Preascitic cirrhotics have a natriuretic "escape" after three weeks on high sodium dietary intake, associated with elevated plasma atrial natriuretic peptide levels and suppression of the renin-angiotensin-aldosterone system. With continued suppressed sympathetic activity, preascitics re-establish complete sodium balance but with a net weight gain and presumed increased intravascular volume, but without ascites. This further elucidates the compensated sodium retaining abnormality that characterises preascitic cirrhosis.     

Filtrate of fermented mycelia from Antrodia camphorata reduces liver fibrosis induced by carbon tetrachloride in rats

AIM: To investigate the effects of filtrate of fermented mycelia from Antrodia camphorata (FMAC) on liver fibro-sis induced by carbon tetrachloride (CCI4) in rats. METHODS: Forty Wistar rats were divided randomly into control group and model group. All model rats were given 200 mL/L CCI4 (2 mL/Kg, po) twice a week for 8 wk. Four weeks after CCI4 treatment, thirty model rats were further divided randomly into 3 subgroups: CCI4 and two FMAC subgroups. Rats in CCI4 and 2 FMAC subgroups were treated with FMAC 0, 0.5 and 1.0 g/kg, daily via gastrogavage beginning at the fifth week and the end of the eighth week. Spleen weight, blood synthetic markers (albumin and prothrombin time) and hepatic malondial-dehyde (MDA) and hydroxyproline (HP) concentrations were determined. Expression of collagen I, tissue inhibitor of metalloproteinases (TIMP)-1 and transforming growth factorβ1 (TGF-β1) mRNA were detected by RT-PCR. Histochemical staining of Masson's trichrome was performed. RESULTS: CCI4 caused liver fibrosis, featuring increased prothrombin time, hepatic MDA and HP contents, and spleen weight and decreased plasma albumin level. Compared with CCI4 subgroup, FMAC subgroup (1 g/kg) significantly decreased the prothrombin time (36.7±7.2 and 25.1±10.2 in CCI4 and FMAC groups, respectively, P<0.05) and increased plasma albumin concentration (22.7±1.0 and 30.7±2.5 in CCI4 and FMAC groups, respectively, P< 0.05). Spleen weight was significantly lower in rats treated with CCI4 and FMAC (1 g/kg) compared to CCI4 treated rats only (2.7±0.1 and 2.4±0.2 in CCI4 and FMAC groups, respectively, P<0.05). The amounts of hepatic MDA and HP in CCI4±FAMC (1 g/kg) subgroup were also lower than those in CCI4 subgroup (MDA: 3.9±0.1 and 2.4±0.6 in CCI4 and CCI4 FMAC groups, respectively, P< 0.01; HP: 1730.7±258.0 and 1311.5±238.8 in CCI4 and CCI4 FMAC groups, respectively, P<0.01). Histologic examinations showed that CCI4 FMAC subgroups had thinner or less fibrotic septa than CCI4 group. RT-PCR analysis indicated that FMAC (1 g/kg) reduced mRNA levels of collagen I, TIMP-1 and TGF-β1 (collagenⅠ: 5.63±2.08 and 1.78±0.48 in CCI4 and CCI4 FMAC groups, respectively, P<0.01; TIMP-1: 1.70±0.82 and 0.34±0.02 in CCI4 and CCI4 FMAC groups, respectively, P<0.01; TGF-β1:38.03±11.9 and 4.26±2.17 in CCI4 and CCI4 FMAC groups, respectively, P<0.01) in the CCI4-treated liver. CONCLUSION: It demonstrates that FMAC can retard the progression of liver fibrosis induced by CCI4 in rats.     

沉默结缔组织生长因子对大鼠肝纤维化及细胞外基质积聚的影响

目的 研究结缔组织生长因子(CTGF)小干扰RNA(siRNA)在CCl4诱导的大鼠肝纤维化模型中的抗肝纤维化作用及其对细胞外基质积聚的影响.方法 雄性SD大鼠30只,随机分成5组.模型组:皮下注射CCl4及经门静脉注射等渗盐水,3 d 1次,连续6周;预防组:皮下注射CCl4及经门静脉注射CTGF siRNA,连续6周;治疗组:皮下注射CCl4 2周,随后给予CTGF siRNA及CCl4 4周;对照siRNA干预组:皮下注射CCl4及经门静脉注射对照siRNA,连续6周;空白对照组:经门静脉注射等渗盐水6周.用HE和Sirius red染色评估大鼠肝组织学变化,RTPCR或(和)Western blot检测肝组织CTGF、Ⅰ与Ⅲ型胶原及层黏连蛋白的表达,放射免疫法检测外周血Ⅲ型前胶原及透明质酸含量.结果 模型组及对照siRNA组大鼠肝组织CTGF、Ⅰ与Ⅲ型胶原及层黏连蛋白基因表达显著上调;与模型组相比,预防组及治疗组由CCl4诱导的CTGF mRNA和蛋白表达及Ⅰ与Ⅲ型胶原、层黏连蛋白mRNA表达分别下调76%±8%、95%±2%、74%±8%、78%±8%、31%±7%和80%±3%、93%±3%、57%±6%、59%±10%、43%±9%(F值分别为68.630,21.234,24.219,16.315和9.716,P值均＜0.01),肝纤维化程度明显减轻,大鼠外周血Ⅲ型前胶原和透明质酸含量也显著降低.结论 经门静脉注射CTGF siRNA能显著抑制实验大鼠肝CTGF基因表达,由此通过阻止细胞外基质积聚而缓解肝纤维化.     

Patterns of regional sympathetic nerve traffic in preascitic and ascitic cirrhosis.

Overactivity of the sympathetic nervous system and portal hypertension are key factors in the development of ascites in cirrhosis. The sympathoexcitation that characterizes the more advanced stages of liver diseases is less clearly defined in preascitic cirrhosis. We measured sympathetic nerve traffic to skeletal muscle (peroneal nerve) and to skin districts by microneurography in (1) 12 Child class A cirrhotic patients with clinically significant portal hypertension (portal pressure gradient > 10 mm Hg, 14.8 +/- 1.2 mm Hg, mean +/- SEM) but without actual or previous ascites, (2) 16 Child class C cirrhotic patients with tense ascites, and (3) 10 patients with mild congestive heart failure, a condition paradigmatic of a marked sympathetic activation. Muscle sympathetic nerve traffic was markedly increased in Child class C subjects as compared with controls (23.9 +/- 1.6 bursts/min, P <.01) and superimposable to that recorded in heart failure patients (52.9 +/- 4.7 vs. 60.3 +/- 2 bursts/min, P = not significant). Muscle sympathetic nerve traffic was also increased in Child class A subjects (41.6 +/- 2 bursts/min, P <.01 vs. controls) although to a lesser extent (P <.05 vs. Child class C patients). Skin sympathetic nerve traffic was within the normal range in all patients. Neurohormones were all markedly increased in Child class C subjects. Only norepinephrine was increased in Child class A patients. Our data show that sympathetic nerve traffic activation (1) is already detectable in Child class A cirrhosis when clinically significant portal hypertension is present but ascites never developed and (2) is not generalized because although muscle traffic is increased, skin traffic is within normal range. The role of drugs modulating sympathoactivation should be investigated in preascitic cirrhosis.     

Nitric oxide and renal functions in liver cirrhosis.

BACKGROUND/AIMS: Nitric oxide, a potent vasodilating agent, has been proposed to play a role in pathogenesis of ascites and hepatorenal syndrome. The aim of this study was to evaluate the interaction between the plasma nitric oxide, nitric oxide synthetase levels and renal functions in patients with different degrees of chronic liver disease. METHODS: The study population included 38 subjects: 14 patients with chronic hepatitis, 11 with preascitic cirrhosis and 13 with ascitic cirrhosis. Nitric oxide and nitric oxide synthetase were determined by colorometric assay. We calculated glomerular filtration rate and fractional sodium excretion. RESULTS: Nitric oxide levels in groups were as follows: 79.28+/-24.86, 99.03+/-21.31, 197.05+/-49.61 microm, respectively. Nitric oxide synthetase levels were 2.64+/-0.56, 3.64+/-0.89, 7.75+/-2.46 micromol/L/sec, respectively. Nitric oxide and nitric oxide synthetase levels in the ascitic cirrhotic group were significantly higher than in the others (p<0.05). When glomerular filtration rates were compared, the only significant difference was determined between the groups with chronic hepatitis and ascitic cirrhosis (92.31+/-25.21, 48.46+/-16.45, p<0.05). Fractional sodium excretion was significantly increased in the ascitic cirrhotic group (4.42+/-2.76, p<0.05). CONCLUSIONS: Nitric oxide and nitric oxide synthetase increased with progression of liver disease, especially in ascitic cirrhosis. We also showed that this increase negatively affects the renal tubular and glomerular functions.     

Decreased hepatic glycogen content and accelerated response to starvation in rats with carbon tetrachloride-induced cirrhosis

Glucose homeostasis and fatty acid metabolism are abnormal in patients with cirrhosis. To assess the metabolic response to starvation in an animal model of cirrhosis, glycogen and fuel metabolism were characterized in rats with CCl4-induced cirrhosis studied 2 wk after 10 weekly doses of CCl4. Plasma concentrations of glucose and beta-hydroxybutyrate were not different between fed CCl4-treated and control rats, but plasma nonesterified fatty acid concentrations were higher in cirrhotic animals (0.25 +/- 0.01 vs. 0.39 +/- 0.04 mmol/L; p less than 0.05). After 12 hr of starvation, the plasma nonesterified fatty acid concentration had reached 0.58 +/- 0.04 mmol/L in CCl4-treated rats, compared with 0.38 +/- 0.04 mmol/L in control rats (p less than 0.05). The redistribution of the hepatic carnitine pool toward acylcarnitines, which is characteristic of starvation, was complete after fasting for 12 hr in the CCl4-treated rats, compared with the 24 hr required in control rats. In fed cirrhotic rats, liver glycogen content per gram liver was decreased by 64% compared with control rats (30.0 +/- 5.1 vs. 10.8 +/- 1.1 mg/gm liver wet wt; p less than 0.05). After 12-hr fasting, hepatic glycogen content had fallen to 14.3 +/- 3.9 and 4.8 +/- 0.4 mg/gm liver wet wt (p less than 0.05) in control and cirrhotic animals, respectively. To further characterize the status of glycogen metabolism in cirrhotic livers, activities of glycogen synthase and glycogen phosphorylase were determined. Hepatic active and total glycogen phosphorylase activities normalized to hepatocellular content were unaffected by CCl4 treatment, whereas total glycogen synthase activity was increased by 45%.(ABSTRACT TRUNCATED AT 250 WORDS)     

实验性肝纤维化Bcl-2、Bax的表达及干扰素-γ对其的作用

目的 研究Bcl-2、Bax蛋白在四氯化碳(CCl4)诱导肝纤维化模型大鼠肝组织中的表达以及干扰素-γ(IFN-γ)对其的作用。 方法用CCl4诱导形成大鼠肝纤维化模型,使用IFN-γ 0.2 MU·kg-1·d-1,肌肉注射,治疗12周,设正常对照组和模型对照组。用免疫组织化学法检测各组大鼠肝组织Bcl-2、Bax的表达情况。 结果 Bcl-2在正常对照组大鼠肝细胞浆和肝窦呈低水平表达,在模型对照组大鼠肝组织分布广泛,主要表达在纤维间隔、汇管区、肝窦和肝细胞膜,中央静脉和肝细胞浆也有一定表达。正常对照组和模型对照组表达量分别为(3.87±2.37)％和(9.46±4.29)％,t=2.83,P<0.05。Bax在正常对照组大鼠肝组织的中央静脉及其周围的肝窦呈低水平表达,在模型对照组主要表达在肝细胞浆,其还表达在肝窦、纤维间隔和肝细胞膜中,胆管上皮细胞偶见表达。正常对照组和模型对照组表达量分别为(3.50±1.88)％和(9.80±3.75)％,t=3.72,P<0.01。IFN—γ组Bax的表达量为(5.85±2.35)％,模型对照组为(9.80±3.75)％,t=2.98,P<0.01,Bcl-2的表达无明显改变(t=1.49,P>0.05)。IFN-γ组对纤维间隔Bcl-2的表达量为(6.58±4.13)％,模型对照组为(9.46±4.29)％,t=2.80,P<0.05,Bax的表达差异无显著性,t=0.58,P>0.05。 结论 肝纤维化时Bcl-2和Bax表达加强,IFN     

One-week losartan administration increases sodium excretion in cirrhotic patients with and without ascites

Background. Losartan, a highly selective angiotensin II type 1 receptor antagonist, has been reported to have a significant portal hypotensive effect in cirrhotic patients. A recent study also showed that losartan exerted a dramatic natriuretic effect in preascitic cirrhosis. The influence of losartan on renal hemodynamics and sodium homeostasis in cirrhotic patients with ascites is unclear. This study was undertaken to evaluate the renal effects of 1-week losartan treatment in cirrhotic patients with and without ascites. Methods. All 12 patients in the study received a daily oral dose of 25 mg losartan for 7 consecutive days. Effective renal plasma flow, urine volume, creatinine clearance, 24h urine sodium excretion and fractional excretion of sodium, blood urea nitrogen, and serum creatinine were measured before and after treatment. Results. In cirrhotic patients without ascites, creatinine clearance, 24-h urinary sodium excretion, and fractional excretion of sodium were significantly increased after losartan administration. Effective renal plasma flow and serum creatinine showed almost no change after treatment. In cirrhotic patients with ascites, creatinine clearance, 24-h urinary sodium excretion, fractional excretion of sodium, and effective renal plasma flow were significantly increased after losartan administration. In addition, the magnitudes of the increases in the fractional excretion of sodium and in the 24-h urinary sodium excretion were greater in cirrhotic patients with ascites than in those without ascites. Conclusions. One-week treatment with losartan increases sodium excretion in association with an improvement of renal function in cirrhotic patients with and without ascites. The natriuretic effect was more profound in cirrhotic patients with ascites than in those without ascites. Received: May 1, 2001 / Accepted: August 24, 2001     

Effect of V1-vasopressin receptor blockade on arterial pressure in conscious rats with cirrhosis and ascites.

Angiotensin II blockade with saralasin in human cirrhosis with ascites is associated with a significant reduction in arterial pressure, indicating that endogenous angiotensin II plays an important role in the maintenance of systemic hemodynamics in this condition. The aim of the current study was to investigate whether vasopressin also contributes to the maintenance of arterial pressure in cirrhosis with ascites. The study was performed using three groups of cirrhotic rats with ascites and three groups of control animals. The administration of d(CH2)5Tyr(Me)AVP, a selective antagonist of the vascular effect of vasopressin, to 10 cirrhotic rats induced a significant reduction in mean arterial pressure (from 94 +/- 4 to 85 +/- 4 mm Hg; P less than 0.001) and a significant increase in plasma renin activity (from 24.3 +/- 4.9 to 34.3 +/- 5.9 ng/mL.h; P less than 0.02) and plasma norepinephrine concentration (from 1474 +/- 133 to 2433 +/- 253 pg/mL; P less than 0.01). Similar results were observed following saralasin administration in a second group of 5 cirrhotic rats [mean arterial pressure decreased from 97 +/- 4 to 85 +/- 5 mm Hg (P less than 0.0001); and plasma renin activity and norepinephrine concentration increased from 18.4 +/- 5.8 to 40.3 +/- 5.7 ng/mL.h (P less than 0.02) and from 1383 +/- 70 to 2312 +/- 334 pg/mL (P less than 0.05), respectively]. The simultaneous blockade of angiotensin II and vasopressin in a third group of cirrhotic rats resulted in a significantly greater reduction of mean arterial pressure (from 97 +/- 6 to 74 +/- 6 mm Hg; P less than 0.05). No changes in arterial pressure were observed in the three groups of control rats. These findings indicate that endogenous vasopressin is as important as angiotensin II in the maintenance of arterial pressure in cirrhotic rats with ascites and support the contention that arterial hypotension is the initial event leading to the stimulation of the renin-angiotensin system and vasopressin in this animal model of cirrhosis.     

Haemodynamic, renal sodium handling, and neurohormonal effects of acute administration of low dose losartan, an angiotensin II receptor antagonist, in preascitic cirrhosis

BACKGROUND: The renin-angiotensin system may be implicated in the subtle sodium handling abnormality in preascitic cirrhosis. AIMS: To assess the role of angiotensin II in sodium homoeostasis in preascitic cirrhosis, using losartan, its receptor antagonist. PATIENTS: Nine male, preascitic cirrhotic patients, and six age matched, healthy male controls. METHODS: A dose response study using 2.5, 5, 7.5, and 10 mg of losartan was performed on a daily 200 mmol sodium intake, followed by repeat studies with the optimal dose, 7.5 mg of losartan, to determine its effects on systemic and renal haemodynamics, renal sodium handling, and neurohumoral factors. RESULTS: Preascitic cirrhotic patients had significantly reduced baseline urinary sodium excretion compared with controls (154 (8) versus 191 (12) mmol/day, p<0.05), associated with significantly reduced systemic angiotensin II levels (6.0 (1.7) versus 39.5 (10.0) pmol/l, p=0.002). Losartan 7.5 mg normalised renal sodium handling in the preascitic cirrhotic patients (202 (12) mmol/day, p=0.05 versus baseline), without any change in systemic or renal haemodynamics, but with significantly increased systemic angiotensin II levels (7.8 (2.3) pmol/l, p=0.05 versus baseline). Losartan had no effect on renal sodium handling in controls. CONCLUSIONS: In preascitic cirrhotic patients, the subtle renal sodium retention, paradoxically associated with low systemic neurohumoral factor levels, is improved with low dose losartan, suggesting the involvement of angiotensin II via its direct action on the renal tubule.     

Effect of preoperative interventions on outcome following liver resection in a rat model of cirrhosis

BACKGROUND/AIMS: High morbidity and mortality rates in cirrhotic patients undergoing resections for hepatocellular malignancies underscore the need for identifying a therapy that will decrease fibrosis or enhance hepatic regenerative activity in the perioperative period. Thus, in the present study, 104 carbon tetrachloride-induced cirrhotic rats received either saline (untreated cirrhotic controls) or one of the following agents that have been reported to decrease hepatic fibrosis or increase hepatic regeneration; pentoxifylline, ciprofloxacin or a traditional Chinese herbal remedy (TCHR). Twelve additional rats served as healthy, non-cirrhotic controls. METHODS: Treatments were administered daily by gavage for 4 weeks followed by a 70% partial hepatectomy. Hepatic fibrosis was documented at the time of surgery by computer-assisted quantitation of collagen content. Liver function and hepatic regenerative activity were documented 24 h post partial hepatectomy by serum bilirubin determinations and a combination of 3[H]-Thymidine incorporation into hepatic DNA and proliferating cell nuclear antigen (PCNA) quantitation, respectively. RESULTS: Compared to untreated cirrhotic controls (8.1 +/- 0.7%), fibrosis was significantly reduced in the pentoxifylline- and ciprofloxacin-treated groups (4.6 +/- 0.2%, p<0.005 and 5.5 +/- 0.6%, p<0.05) but unchanged in the TCHR-treated group (6.6 +/- 11.0%). Post-operatively, total serum bilirubin levels were lower in the pentoxifylline (1.40 +/- 0.15 mg/dl,p<0.01) and ciprofloxacin (1.87 +/- 0.25 mg/dl, p<0.05)-treated groups, but unchanged in the TCHR group (2.20 +/- 0.45 mg/dl), when compared to untreated cirrhotic controls (3.00 +/- 0.37 mg/dl). Hepatic regenerative activity was also significantly improved in the pentoxifylline-treated group (17.8 +/- 2.2 versus 9.9 +/- 1.9 DPM/microg DNA in untreated cirrhotic controls, p<0.05), but unchanged in the ciprofloxacin (16.1 +/- 1.8 DPM/microg DNA) and TCHR (10.9 +/- 1.2 DPM/microg DNA)-treated groups. PCNA protein determinations were in keeping with the 3[H]-Thymidine results CONCLUSIONS: Pre-operative pentoxifylline holds promise as a useful therapeutic intervention for patients with cirrhosis requiring hepatic resection.