Common Bile Duct Ligation Group Research Articles

Evaluation of Electrocardiogram Parameters and Heart Rate Variability During Blood Pressure Elevation by Phenylephrine in Cirrhotic Rats.

Cirrhotic cardiomyopathy is a myocardial disease that may go undetected in the early stages due to peripheral vasodilatation. The aim of the study was to evaluate the electrocardiogram (ECG) and heart rate variability (HRV) after raising blood pressure by phenylephrine injection in rats with liver cirrhosis. Twenty male Sprague-Dawley rats were divided into the Sham and common bile duct ligation (CBDL) groups. After 44days, animals were anesthetized and the right femoral artery and vein catheterized. After a steady-state period, a bolus injection of phenylephrine (PHE, 10μg/μl/IV, baroreflex maneuver) was followed by a slow injection of PHE (100μg/ml/5min/IV, sustained maneuver). Rapid and slow injections of PHE resulted in a greater increase in mean arterial pressure (MAP) and a weaker bradycardia response in the CBDL group than in the Sham group. ECG analysis showed increased QT, QTc, JT, and T peak to T end in the CBDL group, which remained unchanged after PHE injection. On the other hand, the parasympathetic indices of the HF band and RMSSD, and the sympathetic index of the LF band after PHE injection were lower in the CBDL group than in the Sham group.ECG data indicated prolonged ventricular depolarization and repolarization, independent of blood pressure levels in cirrhosis. On the other hand, after PHE injection, the parasympathetic and sympathetic components of HRV decreased, regardless of the duration of elevated blood pressure. We suggest that HRV analysis can provide a useful approach to assess cardiac dysfunction associated with elevated blood pressure in cirrhosis.

Reversal of cholestatic liver disease by the inhibition of sphingosine 1-phosphate receptor 2 signaling.

The objective of this study is to examine the impact of inhibiting Sphingosine 1-phosphate receptor 2 (S1PR2) on liver inflammation, fibrogenesis, and changes of gut microbiome in the context of cholestasis-induced conditions. The cholestatic liver injury model was developed by common bile duct ligation (CBDL). Sprague-Dawley rats were randomly allocated to three groups, sham operation, CBDL group and JTE-013 treated CBDL group. Biochemical and histological assessments were conducted to investigate the influence of S1PR2 on the modulation of fibrogenic factors and inflammatory infiltration. We conducted an analysis of the fecal microbiome by using 16S rRNA sequencing. Serum bile acid composition was evaluated through the utilization of liquid chromatography-mass spectrometry techniques. In the BDL rat model, the study findings revealed a significant increase in serum levels of conjugated bile acids, accompanied by an overexpression of S1PR2. Treatment with the specific inhibitor of S1PR2, known as JTE-013, resulted in a range of specific effects on the BDL rats. These effects included the improvement of liver function, reduction of liver inflammation, inhibition of hepatocyte apoptosis, and suppression of NETosis. These effects are likely mediated through the TCA/S1PR2/NOX2/NLRP3 pathway. Furthermore, the administration of JTE-013 resulted in an augmentation of the diversity of the bacterial community's diversity, facilitating the proliferation of advantageous species while concurrently inhibiting the prevalence of detrimental bacteria. The results of our study suggest that the administration of JTE-013 may have a beneficial effect in alleviating cholestatic liver disease and restoring the balance of intestinal flora.

Neutrophil depletion reduces interstitial cajal-like cell injury and alleviates inflammation-induced motor dysfunction in guinea-pig gallbladder during acute cholecystitis.

Objective(s):Gallbladder interstitial Cajal-like cells (ICLCs) are known as some of the players in the complex motility mechanisms affecting gallbladder motility. This study aims to explore the mechanism of guinea-pig gallbladder motility disorders during Acute Cholecystitis (AC), focusing on the relationships between neutrophil alterations, gallbladder ICLCs, and smooth muscle contractility.Materials and Methods:Forty-eight guinea pigs were randomly divided into four groups: normal, sham, common bile duct ligation (CBDL), and anti-PMN (anti-polymorphonuclear antibody treated +CBDL). Hematoxylin and eosin-stained slides from each gallbladder sample were examined for inflammation, and myeloperoxidase (MPO) activity was evaluated. The contractile response of gallbladder muscle to Ach, CCK-8, and KCl was registered by a tension transducer, and ultrastructure features of ICLCs were observed.Results:Pretreatment with anti-PMN significantly reduced the circulating neutrophils by 80% and also considerably decreased the gallbladder MPO activity by 52.9% compared with the CBDL group (P<0.05). After adding Ach, CCK-8, and KCl, the contraction ability in CBDL and anti-PMN groups was lower than those of normal and sham groups (P<0.05), and they were increased substantially in the anti-PMN group compared with the CBDL group (P<0.05). Transmission electron microscopy confirmed that the cytoplasm of the neutrophils was full of granules, and neutrophils contacted closely with ICLCs. The ultrastructure of ICLCs in the anti-PMN group was less inflamed and the endoplasmic reticulum was mildly dilated, and cell processes also increased.Conclusion:Anti-PMN could relieve the ultrastructure injury of ICLCs and alleviate gallbladder dysmotility during AC. Neutrophils may damage gallbladder ICLCs at first followed by dysmotility.

Roles of Endothelin B Receptors and Endothelial Nitric Oxide Synthase in the Regulation of Pulmonary Hemodynamic in Cirrhotic Rats.

Hepatopulmonary syndrome and portopulmonary hypertension are common complications of liver disorders. This study aimed to determine roles of ET-B receptors and endothelial-derived NO synthase in the regulation of pulmonary hemodynamic in cirrhotic rats. Male Sprague-Dawley rats were divided into the Sham and common bile duct ligation (CBDL) groups. After 28 days, animals were anesthetized, and the right ventricle, femoral artery, and vein cannulated. Then, intravenous injection of BQ-788 (a selective ET-B receptor antagonist) and L-NAME (eNOS inhibitor) were performed sequentially. After the first injection of BQ-788, the right ventricular systolic pressure (RVSP) and mean arterial systemic pressure increased only in the Sham group. L-NAME increased RVSP in the Sham and CBDL groups, whereas mean arterial systemic pressure elevated only in the Sham group significantly. Reinjection of BQ-788 increased RVSP in the Sham group, whereas it decreased RVSP in the CBDL group. Both plasma NO metabolites and lung endothelin-1 increased in the CBDL group. ET-B receptors on the endothelial cells play roles in the regulation of pulmonary and systemic vascular tone in normal condition through the NO-mediated pathway, whereas ET-B receptors on the smooth muscle cells have a role in the pulmonary vascular tone in liver cirrhosis.

Effects of Octreotide and Allopurinol on Liver Histology and Functions in Surgical Jaundice: An Experimental Study

Aim: Mechanical jaundice may lead to adverse metabolic effects in surgical patients. Our aim was to investigate the effects of octreotid and allopurinol on liver histology and functions in rats with experimantally created mechanical jaundice.&#x0D; Methods: The subjects were divided into five main groups. The rats in Group I (Control) received no interventions. In Group II, common bile duct ligation (CBDL) was performed. In Group III, the same ligation procedure was performed followed by the administration of octreotid. In Group IV, the rats received allopurinol following CBDL and in Group V (Sham), the common bile duct was dissected and left intact. After sacrification of each rat on the seventh postoperative day, blood samples were collected for serum hematocrit, direct bilirubin, alanine aminotransferase (ALT), aspartate aminotransferase (AST), amylase, and albumin measurements in addition to the histopathologic examinations of the collected tissue specimens from the liver, terminal ileum, and pancreas. According to statistical analysis, a value of p&lt;0.05 was considered as significant.&#x0D; Results: The direct bilirubin, AST and ALT levels were detected to be significantly elevated in the groups II, III and IV, in which CBDL was performed (p&lt;0.05). While significant reductions of serum direct bilirubin, AST and ALT levels were detected in the octreotide group, these parameters were significantly elevated in the allopurinol group (p&lt;0.05 and p&lt;0.05, respectively). There was no significant difference of hematocrit and albumine levels among the study groups (p&gt;0.05). Additionally, in the allopurinol group four rats were found to have increased serum amylase levels and the histopathologic evaluations of their pancreatic samples revealed findings of pancreatitis. According to the histopathologic examinations, significant alterations were detected between the control and sham groups (groups I, V) and the CBDL groups (groups II, III, IV). However, these histopathological findings revealed no significant differences within the subgroup of subjects including CBDL alone (Group II), and CBDL along with the administration of either octreotide (Group III), or allopurinol (Group IV).&#x0D; Conclusion: The use of octreotide in mehanical jaundice may have protective metabolic effects. Further studies are considered necessary to be carried to support these findings.

The Relationship between Liver Dysfunction, Electrocardiographic Abnormalities and Metabolism in Rat

Introduction: Liver disorders may lead to many critical complications such as electrical heart abnormalities. The aim of this study was to investigate the relationship between the severity of liver dysfunctions, electrocardiogram variables and oxygen consumption. Methods: Female Sprague Dawley rats were divided into 4 groups of sham, partial portal vein ligation (PPVL), common bile duct ligation (CBDL), and combination of them (CBDL+ PPVL). 28 days after the first surgery, animals were anesthetized; ECG recorded and right femoral artery and vein cannulated. Blood gas parameters and complete blood count were measured and the arterial-venous oxygen content difference (A-VO2) calculated. Results: QT interval and QTc in the CBDL+PPVL and CBDL groups were longer than those of the sham and PPVL groups. Furthermore, there were abnormal and bizarre T waves in the CBDL and CBDL+PPVL groups. In the CBDL+PPVL group, arterial O2 pressure was lower while arterial CO2 pressure and plasma concentration of HCO3- were higher than those of the other groups. A-VO2 in the CBDL+PPVL group was also lower than those of the other groups, and in the CBDL group was less than that of the PPVL group. Conclusions: In this study, we detected bizarre T waves and increased QT interval and QTc in the ECG of cirrhotic rats, which could be partly linked to the severity of liver dysfunction and reduction of metabolism.

Molecular mechanism of tumor necrosis factor-alpha monoclonal antibody in hepatopulmonary syndrome in rats

To investigate the molecular mechanism of tumor necrosis factor-alpha (TNF-a) monoclonal antibody (McAb) in hepatopulmonary syndrome using a rat model. Sixty adult male Sprague-Dawley rats, weighing 250 ± 25 g, were randomized to a sham operation group, a common bile duct ligation (CBDL) group, or a CBDL+TNF-alphat McAb treatment group. The CBDL operation group was further divided into five subgroups, and the CBDL+TNF-alpha McAb treatment group was further divided into four subgroups. After the experimental period, all rats were sacrificed for excision of lung and liver tissues. Hematoxylin-eosin (HE) and Masson staining were performed to observe the extent of liver fibrosis,and HE staining was used to histopathologically assess changes in the lung tissue. Immunohistochemistry and western blotting were used to investigate the changes in expression levels of FAK, p-FAK and PTEN in lung. The extent of inflammatory responses and fibrosis in the liver was significantly lower in the CBDL+TNF-alpha McAb treatment group as compared to those in the CBDL group. The inflammatory responses in the lung were also significantly lower in the CBDL+TNF-alpha McAb treatment group as compared to that in the CBDL group. The CBDL+TNF-alpha McAb treatment group also showed less extensive distribution of FAK and p-FAK protein in lung tissues,but more extensive distribution of PTEN protein. FAK and PTEN are associated with hepatopulmonary syndrome in rats. The therapeutic effect of TNF-alpha McAb may involve modulation of the expression of FAK and PTEN.

Probiotics (VSL#3) prevent endothelial dysfunction in rats with portal hypertension: role of the angiotensin system.

AimsPortal hypertension characterized by generalized vasodilatation with endothelial dysfunction affecting nitric oxide (NO) and endothelium-dependent hyperpolarization (EDH) has been suggested to involve bacterial translocation and/or the angiotensin system. The possibility that ingestion of probiotics prevents endothelial dysfunction in rats following common bile duct ligation (CBDL) was evaluated.MethodsRats received either control drinking water or the probiotic VSL#3 solution (50 billion bacteria.kg body wt−1.day−1) for 7 weeks. After 3 weeks, rats underwent surgery with either resection of the common bile duct or sham surgery. The reactivity of mesenteric artery rings was assessed in organ chambers, expression of proteins by immunofluorescence and Western blot analysis, oxidative stress using dihydroethidium, and plasma pro-inflammatory cytokine levels by flow cytometry.ResultsBoth NO- and EDH-mediated relaxations to acetylcholine were reduced in the CBDL group compared to the sham group, and associated with a reduced expression of Cx37, Cx40, Cx43, IKCa and SKCa and an increased expression of endothelial NO synthase (eNOS). In aortic sections, increased expression of NADPH oxidase subunits, angiotensin converting enzyme, AT1 receptors and angiotensin II, and formation of ROS and peroxynitrite were observed. VSL#3 prevented the deleterious effect of CBDL on EDH-mediated relaxations, vascular expression of connexins, IKCa, SKCa and eNOS, oxidative stress, and the angiotensin system. VSL#3 prevented the CBDL-induced increased plasma TNF-α, IL-1α and MCP-1 levels.ConclusionsThese findings indicate that VSL#3 ingestion prevents endothelial dysfunction in the mesenteric artery of CBDL rats, and this effect is associated with an improved vascular oxidative stress most likely by reducing bacterial translocation and the local angiotensin system.

Atividade da mieloperoxidase está aumentada na síndrome hepatopulmonar em ratos

Hepatopulmonary syndrome is formed by a triad of liver disease, intrapulmonary vascular dilatation and changes in blood gases. Its pathogenesis is not well defined, but it is speculated that a combination of factors, such as the imbalance of endothelin receptor responses, pulmonary microvascular remodeling, and genetic predisposition, leads to bacterial translocation and intrapulmonary vascular dilatation. To evaluate the myeloperoxidase activity in hepatopulmonary syndrome in rat model. Twenty-nine rats were divided into control, sham and experimental hepatopulmonary syndrome groups. Was evaluated the myeloperoxidase activity and the experimental model used to induce hepatopulmonary syndrome was common bile duct ligation. The myeloperoxidase activity levels were significantly increased in the common bile duct ligation group as compared with the other groups. Myeloperoxidase activity was higher in the common bile duct ligation group than control group (p<0.05) and than sham group (p<0.05). The myeloperoxidase activity is increased in experimental hepatopulmonary syndrome in rats.

Role of serine threonine protein kinase-1 and Smad3 in lung tissues in development of hepatopulmonary syndrome in rats

Objective To investigate the role of serine threonine protein kinase-1 (Akt1) and Smad3 in lung tissues in development of hepatopulmonary syndrome in rats.Methods Seventy-two healthy male SpragueDawley rats,aged 3-4 months,weighing 200-250 g,were randomly divided into 3 groups (n=24 each):control group (C group),sham operation group (S group) and common bile duct ligation (CBDL) group.The rats were anesthetized with 3％ pentobarbital sodium 45 mg/kg.In group CBDL,laparotomy was performed,the common bile duct was ligated and then the abdomen was closed,while the common bile duct was only exposed,but not ligated and then the abdomen was closed in group S.At 1st,3rd and 5th weeks (T1-3),8 rats were chosen randomly in each group and blood samples were obtained from the abdominal aorta for blood gas analysis.The rats were then sacrificed and lungs were isolated to detect the expression of Aktl and Smad3 mRNA and protein in lung tissues (by RT-PCR and Western blot).The lung tissues were sliced and stained with hematoxylin eosin for examination of the pathological changes of pulmonary capillaries.Results Compared with C and S groups,the expression of Akt1 and Smad3 mRNA and protein in lung tissues was significantly up-regulated at T2,3,and alveolar-arterial oxygen tension difference was increased at T3 in CBDL group (P ＜ 0.05).The pulmonary capillary was obviously dilated at T3 in CBDL group.Conclusion The expression of Akt1 and Smad3 in lung tissues is up-regulated,which may be one of the mechanisms of development of hepatopulmonary syndrome in rats. Key words: Hepatopulmonary syndrome ; Lung ; Protein-serine-threonine kinases ; Smad3 protein

Triplex forming oligonucleotides against type α1(I) collagen attenuates liver fibrosis induced by bile duct ligation

Liver fibrosis is a consequence of chronic liver disorders which lead to the accumulation of extracellular matrix (ECM). Particularly, there is an increased accumulation of collagen in the fibrotic liver. We have therefore used a triplex forming oligonucleotide (TFO) against the type α1(I) collagen and evaluated, whether it can attenuate liver fibrosis induced by common bile duct ligation (CBDL) in rats. There was a significant decrease in hydroxyproline levels and Masson's trichrome staining for collagen in TFO-treated CBDL groups compared to non-treated CBDL group. There was over expression of type α1(I) collagen, α-smooth muscle actin (α-SMA) and TGF-β1 expression in the CBDL group compared to TFO-treated CBDL group. Also, the serum alanine transaminase (ALT) and aspartate transaminase (AST) concentrations were less in the TFO treated group compared to non-treated CBDL group. There was also less neutrophils accumulation in TFO treated CBDL group assayed by myeloperoxidase (MPO) assay. These results suggests that TFO can be used to downregulate type 1 collagen gene expression and can alleviate liver fibrosis induced by common bile duct ligation.

Significance of MD-2 and MD-2B expression in rat liver during acute cholangitis

To investigate the expression of myeloid differentiation protein-2 (MD-2), MD-2B (a splicing isoform of MD-2 that can block Toll-like receptor 4 (TLR4)/MD-2 LPS-mediated signal transduction) and TLR4 in the liver of acute cholangitis rats. Male Sprague-Dawley rats (SPF level) were randomly divided into four groups: (A) sham-operated group; (B) simple common bile duct ligation group; (C) acute cholangitis group; and (D) acute cholangitis anti-TLR4 intervention group (n = 25 per group). Rat liver tissue samples were used to detect TLR4, MD-2 and MD-2B mRNA expression by fluorescence quantitative PCR in parallel with pathological changes. In acute cholangitis, liver TLR4 and MD-2 mRNA expression levels at 6, 12, 24, 48 and 72 h were gradually up-regulated but MD-2B mRNA expression gradually down-regulated (P < 0.05). After TLR4 antibody treatment, TLR4 and MD-2 mRNA expression were lower compared with the acute cholangitis group (P < 0.05). However, MD-2B mRNA expression was higher than in the acute cholangitis group (P < 0.05). MD-2 and TLR4 mRNA expressions were positively correlated (r = 0.94981, P < 0.05) and MD-2B mRNA expression was negatively correlated with MD-2 and TLR4 mRNA (r = -0.89031, -0.88997, P < 0.05). In acute cholangitis, MD-2 plays an important role in the process of TLR4- mediated inflammatory response to liver injury while MD-2B plays a negative regulatory role.

Effect of Nitric Oxide/Cyclic Guanosine Mono-phosphate Pathway on Gallbladder Relaxant Response in Bile Duct-Ligated Guinea Pigs

Background/Aims: Common bile duct ligation (CBDL) in the guinea pig is a well-defined model of acalculous cholecystitis. Nitric oxide (NO) mediates smooth muscle relaxation by stimulating the activity of soluble guanylate cyclase. The aim of this study was to determine whether the NO/cyclic guanosine monophosphate pathway plays a role in gallbladder relaxant response after CBDL. Methods: Relaxant response of gallbladder muscle strips from CBDL and sham-operated guinea pigs was studied in vitro. Animals were treated with saline, aminoguanidine or an aminoguanidine + L-arginine combination in vivo. Concentration-response curves of papaverine, diethylamine/NO, YC-1, sildenafil and amrinone were obtained and relaxations in each group were calculated as the percent of the contractions induced by carbachol (10^–6 M). Results: There was a significant decrease in the gallbladder muscle relaxant responses to these substances in CBDL and aminoguanidine groups compared with sham surgical controls. The decreased relaxant response was reversed by aminoguanidine + L-arginine but not by aminoguanidine alone. Conclusion: Decreased relaxant responses might be due to the reduced guanylate cyclase enzyme activity, but further studies are required.

Effect of all-trans retinoic acid on liver fibrosis induced by common bile duct ligation in rats

The aim of this study was to investigate the effect and possible mechanism of all-trans retinoic acid (ATRA) on liver fibrosis induced by common bile duct ligation (CBDL) in rats. Fifty-three female Wistar rats were randomly divided into 5 groups: sham operation group (group J, 5 animals) and groups A, B, C and D (12 animals in each group). The rats in groups A, B, C and D were subjected to CBDL to induce liver fibrosis, while those in group J to sham operation. From the 3rd week the rats in groups B, C and D respectively received daily administration of ATRA via gastric tube at three different doses [0.1, 1.5 and 7.5 mg/kg body weight (BW)]. Animals were sacrificed at 6th week. Rats' liver tissues were observed for pathologic changes under a light microscope. The protein levels of type I collagen (COL I), matrix metalloproteinase-2 (MMP2), MMP13 and tissue inhibitors of metalloproteinase-1 (TIMP-1) in liver tissues were determined by immunohistochemical techniques. The expression levels of TGF-beta1 and CTGF mRNA in liver tissues were detected by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR). The results showed that loss of normal hepatic architecture and formation of obvious fibrosis were observed in group A, while ATRA treatment for 4 weeks notably alleviated the pathological changes of hepatocytes. The expression of COL I and TIMP-1 proteins in group A was increased, while decreased in ATRA-treated CBDL groups (P<0.05). ATRA (1.5 and 7.5 mg/kg BW) reduced the expression levels of COL I protein more greatly than that of 0.1 mg/kg BW (P<0.05). ATRA treatment increased the protein levels of MMP2 and MMP13. The expression levels of TGF-beta1 and CTGF mRNA in group A were increased. In comparison with group A, the mRNA levels of TGF-beta1 and CTGF in ATRA-treated CBDL groups were significantly decreased (P<0.05). It was concluded that ATRA could inhibit CBDL-induced liver fibrosis in rats by suppressing the expression of TGF-beta1 and CTGF so as to diminish the inhibition of TIMP-1 on MMP2 and MMP13 and increase the activity of MMP2 and MMP13.

Decreased expression of intestinal chemokine TECK/CCL25 in experimental obstructive jaundice and its reversal following internal biliary drainage

Although bacterial translocation is a significant problem in patients with obstructive jaundice, how translocation is promoted in this situation is not clearly understood. We previously reported the recovery of gut mucosal T-lymphocyte numbers in jaundiced rats following internal biliary drainage. This suggests that bile in the intestinal lumen promotes T-lymphocyte redistribution into the gut mucosa. To test this hypothesis, we have examined the expression patterns of chemokines that play an important role in lymphocyte recruitment into the small intestine. Four groups of rats receiving one of the following surgical procedures were studied: a sham operation (SHAM), common bile duct ligation (CBDL), CBDL followed by external drainage, or CBDL followed by internal drainage. Expression levels of intestinal mRNAs encoding TECK, MECK, and LARC chemokines were assessed using real-time polymerase chain reaction. Distribution of chemokine mRNA in the rat ileum was examined using in situ hybridization (ISH). Following surgery, the expression levels of TECK mRNA decreased significantly in the CBDL group compared with in the SHAM group. While TECK expression did not recover after external drainage, it recovered to a near-normal level after internal drainage. Expression levels of MECK and LARC mRNAs were similar among all groups. ISH confirmed strong expression of TECK mRNA in the epithelial cells of the small intestine. These results indicate that bile may contribute to high expression levels of TECK/CCL25 mRNA in the small intestine. Bile may also have a role in regulating the distribution of gut mucosal T lymphocytes by promoting TECK production from epithelial cells.

N‐Acetylcysteine Effects on Genotoxic and Oxidative Stress Parameters in Cirrhotic Rats with Hepatopulmonary Syndrome

The aim of this study was to evaluate the potential antioxidant effects of N-acetylcysteine in hepatopulmonary syndrome, a complication of cirrhosis, using an experimental model of common bile duct ligation in rats. Male Wistar rats were divided into four experimental groups: CBDL (animals submitted to common bile duct ligation); Sham (animals submitted to simulated common bile duct ligation); Sham + N-acetylcysteine, and CBDL + N-acetylcysteine. N-acetylcysteine (10 mg/kg, intraperitoneally) was administered for 2 weeks starting on day 14 after surgery. Some alterations in the liver integrity were investigated by evaluation of serum enzymes aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and arterial blood gases. Lipoperoxidation by thiobarbituric acid-reactive substances assay, superoxide dismutase activity and total nitrates was measured as parameters of oxidative stress, performed on lung homogenates. Micronucleus assay in bone marrow and comet assay in lung, liver and blood were performed to assess the genotoxic effects by oxidative stress. The results showed an improvement in the enzymatic parameters and arterial blood gases, a reduction of lipoperoxidation and in the total nitrates after treatment with N-acetylcysteine. Histological analysis showed vasodilatation in the lung, which was reversed by N-acetylcysteine. Micronuclei frequency and DNA damage in lung and liver were increased in the CBDL group. N-Acetylcysteine caused no genotoxic effect and did not influence the induction of micronucleus in bone marrow and DNA damage in lung and liver. The results suggest protective effects after treatment with N-acetylcysteine in cirrhotic rats with hepatopulmonary syndrome.

Effect of ATRA on contents of liver retinoids, oxidative stress and hepatic injury in rat model of extrahepatic cholestasis

The effects of all-trans-retinoic acid (ATRA) administration on the concentration of retinoids (RA and vitamin A) in liver, oxidative stress and the hepatic injury in a rat model of common bile duct ligation (CBDL)-induced liver injury were investigated. Female rats were subjected to a sham (n=5) or CBDL (n=48). Two weeks after operation, rats undergoing CBDL were randomized to receive treatment with either ATRA at three different doses (0.1, 1.5, 7.5 mg/kg) dissolved in bean oil or only bean oil every day over a 4-week experimental period. Rats were killed and blood samples were collected from the heart for determination of the serum transaminase. The contents of retinoids in rat liver were detected by using HPLC. Malondialdehyde (MDA), glutathione (GSH) and superoxide dismutase (SOD) levels in liver were determined by a spectrophotometric method according to the instruction of the kits. Liver pathologic changes were observed under the light microscopy and electron microscopy. The results showed that compared with sham-operated group, the levels of retinoids in the liver tissue were significantly decreased in the CBDL group (P<0.01). ATRA (0.1 mg/kg) administration in CBDL rats partially restored the contents of retinoids (P<0.05). Liver RA and vitamin A contents in CBDL group were significantly increased after ATRA (1.5 and 7.5 mg/kg) supplementation as compared with sham-operated group (P<0.05). However, in ATRA-treated CBDL group, hepatic GSH level and SOD activity, depressed by CBDL, and hepatic MDA level, increased by CBDL were returned to those in sham-operated group (P<0.05). The histologic observation of liver tissues indicated that ATRA treatment notably alleviated hepatocellular swelling, steatosis, the swelling of mitochondria and proliferation of smooth endoplasmic reticulum (SER). Treatment with ATRA could reduce levels of serum transaminase as compared with sham-operated group, more greatly in 1.5 and 7.5 mg/kg ATRA-treated groups than in 0.1 mg/kg ATRA-treated group. It was concluded that ATRA treatment can recover MDA and GSH levels and SOD activity in CBDL rat liver through restoring RA and vitamin A contents, and eventually ameliorate liver injury.

The Effects of Saccharomyces boulardii on Bacterial Translocation in Rats with Obstructive Jaundice

The aim of this study was to investigate the effect of Saccharomyces boulardii treatment on preventing bacterial translocation in an obstructive jaundice animal model. Sixty adult rats were divided into five groups: group 1 - the sham-operated group; group 2 - the common bile duct ligation group; group 3 - the S. boulardii group; group 4 - the ampicillin-sulbaktam group; and group 5 - the S. boulardii plus ampicillin-sulbaktam group. The saline, antibiotics and S. boulardii were given, respectively, for a 7-day period as a single dose per day via temporary orogastric intubation. Seven days following the obstructive jaundice, the animal had laparatomy under sterile conditions. Segments of ileum were removed for histopathological examination. Blood, liver, spleen and mesenteric lymph nodes were taken for microbiological culture. Bacterial translocation rates were 0% in the sham-operated group, 83% in group 2, 42% in group 3, 42% in group 4 and 33% in group 5. Bacterial translocation significantly increased in group 2 compared to groups 3, 4 and 5 (P = 0.001). The bacterial counts (CFU/g) of group 2 were significantly higher than those of groups 3, 4 and 5 (P = 0.001). Histopathological examination of ileum specimens revealed a significant decrease in the heights of villi in groups 2-5 compared to the sham-operated group (P = 0.001). The mean villus height in groups 3 and 5 was significantly higher than that of group 4 (P = 0.001). S. boulardii was found to be effective in the successful control of translocation and improvement of intestinal barrier function.

Correlation between pulmonary endothelin receptors and alveolar-arterial oxygen gradient in rats with hepatopulmonary syndrome

The correlation between pulmonary endothelin receptors and alveolar-arterial oxygen gradient (A-aDO2) in rats with hepatopulmonary syndrome was investigated. Animals were divided into 2 groups: Sham-operated (Sham) group and common bile duct ligation (CBDL) group. Arterial blood gas was evaluated by a blood gas analyzer. The concentrations of ET-1 in blood and lung tissue sample were evaluated by radioimmunoassay. The distribution and expression of two kinds of subtype receptor of ET-1, ETRA and ETRB were examined by in situ hybridization. The results showed that the level of A-aDO2 was higher in CBDL group than that in Sham group (P < 0.05). The levels of plasma and pulmonary ET-1 in CBDL group were both higher than in Sham group (P < 0.05). There was no significant difference in average A of ETRA between two groups by imaging analysis (0.21 +/- 0.06 vs 0.22 +/- 0.08, P > 0.05), while that of ETRB was higher in CBDL group than in Sham group (0.58 +/- 0.16 vs 0.28 +/- 0.07, P < 0.05). The expression of ETRB in lung was positively correlated with A-aDO2 (P < 0.05). It was concluded that the widened A-aDO2 may be related with enhancement of the expression of ETRB in lung.

Internal biliary drainage improves decreased number of gut mucosal T lymphocytes and MAdCAM-1 expression in jaundiced rats

BackgroundAlthough the effect of preoperative biliary drainage in patients with obstructive jaundice is controversial, bacterial or endotoxin translocation is one of the main postoperative problem in jaundiced patients. Failure in gut barrier functions causes bacterial translocation; homing and distribution of T lymphocytes in the intestinal lamina propria are important for gut mucosal immune defense. This study was performed to examine whether bile regulates the numbers of T lymphocyte subsets or the expression of mucosal addressin cell adhesion molecule-1 (MAdCAM-1) in experimental jaundice in rats with and without external and internal biliary drainage. MethodsFour groups of Wistar rats were used: those that received a sham operation (SHAM), common bile duct ligation (CBDL), CBDL followed by external drainage (ED), and CBDL followed by internal drainage (ID). Numbers of CD4+ and CD8+ T lymphocytes and MAdCAM-1–positive cells in the lamina propria were counted immunohistochemically in the specimens of jejunum and ileum of each group. Bacterial translocation was examined by culturing from the mesenteric lymph node complex isolated from rats in each group. ResultsA significant decrease in numbers of CD4+ and CD8+ T lymphocytes and MAdCAM-1–positive cells in the lamina propria was seen in obstructive jaundice, although numbers of peripheral blood lymphocytes increased in comparison with the sham-operated control. The numbers of CD4+ and CD8+ T lymphocytes and MAdCAM-1 expression in the lamina propria did not recover to a normal level after external drainage, but did so after internal drainage. Frequencies of bacterial translocation were high in the CBDL and ED group. In contrast, bacterial translocation was not present in any animals in the SHAM group and was at a low percentage in the ID group. ConclusionsChanges in the number of T lymphocytes and MAdCAM-1 expression are associated with the presence of bile in the gastrointestinal tract and are inversely correlated with the frequency of bacterial translocation induced by CBD ligation. MAdCAM-1 expression maintained by the presence of bile may regulate T-lymphocyte homing to the lamina propria in obstructive jaundice.