Enzyme Activity In Liver Tissue Research Articles

Differences in body condition and hepatic cellular metabolism among distinct populations of cestode-infected pumpkinseed sunfish (Lepomis gibbosus)

Host populations can vary in the prevalence and intensity of their parasites, which may influence the impacts of infection on host physiology and health. Parasite-induced effects on hosts may be due to underlying changes in cellular energy metabolism, predominantly driven by the mitochondria. However, limited research has been conducted on understanding variation in host–parasite interactions across populations. We sampled three wild populations of pumpkinseed sunfish ( Lepomis gibbosus (Linnaeus, 1758)), two of which are infected by cestodes, to study correlations among infection intensity, host body condition, and key metabolic enzyme activities in liver tissue. In both infected populations, cestode infection was associated with reduced hepatic lipid metabolism and increased hepatic lactic fermentation. Interestingly, Lake Cromwell fish showed a decrease in body condition, electron transport system activity, and antioxidant activity with cestode intensity, whereas the contrary was observed for Lake Long fish. This suggests that Lake Long fish could be boosting their immune system and food intake to better tolerate infection, unlike Cromwell fish. This study not only highlights how different populations can vary in their response to parasite infections but also the importance of accounting for infection when studying animal physiology.

The Effect of Sevoflurane and Fullerenol C 60 on the Liver and Kidney in Lower Extremity Ischemia-Reperfusion Injury in Mice with Streptozocin-Induced Diabetes.

This study aimed to demonstrate whether fullerenol C60, sevoflurane anesthesia, or a combination of both had protective effects on the liver and kidneys in lower extremity ischemia-reperfusion injury (IRI) in mice with streptozocin-induced diabetes. A total of 46 Swiss albino mice were divided into six groups as follows: control group (group C, n=7), diabetes group (group D, n=7), diabetes-ischemia/reperfusion (group DIR, n=8), diabetes-ischemia/reperfusion-fullerenol C60 (group DIR-FC60, n=8), diabetes-ischemia/reperfusion-sevoflurane (group DIR-S, n=8), and the diabetes-ischemia/reperfusion-fullerenol C60-sevoflurane (group DIR-S-FC60, n=8). Fullerenol C60 (100mg/kg) was administered intraperitoneally 30 min before the ischemia-reperfusion procedure to the fullerenol groups (DIR-FC60 and DIR-S-FC60). In the DIR groups, 2 hours (h) ischemia-2h reperfusion periods were performed. In the sevoflurane groups, sevoflurane was applied during the ischemia-reperfusion period with 100% O2. Liver and kidney tissues were removed at the end of the reperfusion procedure for biochemical and histopathological examinations. In liver tissue, hydropic degeneration, sinusoidal dilatation, pycnotic nuclei, prenecrotic cells, and mononuclear cell infiltration in parenchyma were significantly more frequent in group DIR than in groups D and group C. In terms of the histopathologic criteria examined, more positive results were seen in group DIR-FC60, and when group DIR-FC60 was compared with group DIR, the difference was significant. The best results in AST, ALT, glucose, TBARS levels, and SOD enzyme activities in liver tissue were in group DIR-FC60 compared with group DIR, followed by groups DIR-S-FC60 and DIR-S, respectively. Regarding TBARS levels and SOD enzyme activities in kidney tissue, the best results were in groups DIR-FC60, DIR-S-FC60, and DIR-S, respectively. According to our findings, it is clear that fullerenol C60 administered intraperitoneally 30 min before ischemia, alone or together with sevoflurane, reduces oxidative stress in distant organ damage caused by lower extremity IRI, and reduces liver and kidney tissue damage in histopathologic examinations.

A Comparative Study on Growth Performance, Body Composition, and Liver Tissue Metabolism Rearing on Soybean Lecithin-Enriched Artemia Nauplii and Microdiet in Rock Bream (Oplegnathus fasciatus) Larvae.

This study is aimed at establishing optimal soybean lecithin (SL) enrichment protocols in Artemia nauplii and at comparing the growth performance, body composition, and liver tissue metabolism in rock bream (Oplegnathus fasciatus) larvae reared on SL-enriched Artemia nauplii or SL-enriched microdiet (MD). The enrichment protocol experiment results indicated 12 h enrichment, and 10 g SL/m3 seawater could obtain desirable results. Rock bream larvae (25 days posthatching (dph)) were fed Artemia nauplii or MD for 30 days with three replicates. At stage 1 (larval 25-40 dph), significantly higher growth performance was observed in larvae fed the live prey (P < 0.05). Conversely, at stage 2 (41-55 dph), feeding with MD significantly increased larval standard length, and specific growth rate compared with those of larvae fed live prey. Larvae fed a MD showed decreased lipolysis-related lipase activity as well as decreased amino acid catabolism-related alanine aminotransferase and aspartate aminotransferase enzyme activities in liver tissue. RNA sequencing revealed that feeding with the MD primarily increased the expression of lipogenesis-related genes and protein translation-related gene expression in the liver tissue. Notably, feeding with MD significantly increased ribosome biogenesis-related genes as well as mitochondria synthesis-related gene expression, indicating a high protein anabolism rate and high energy production in liver tissue. In conclusion, 10 g SL/m3 seawater and 12 h could effectively enrich SL in Artemia nauplii. Retard weaning onto MD led to lower growth performance, which was likely due to the diversity of lipid and protein metabolism.

Enzymes of Fibrosis in Chronic Liver Disease.

Liver fibrosis has been extensively studied at the cellular and molecular level, but very few data exist on the final enzymatic stages of collagen synthesis (prolyl hydroxylase, PH) and degradation (matrix metalloproteinases, MMPs), particularly in primary biliary cholangitis (PBC). We studied enzyme activities in liver tissue from patients with chronic liver diseases and compared them to normal livers. Eighteen patients with PBC of early and late stages (Ludwig's classification) and seven on treatment with ursodeoxycholate (UDCA) were studied and compared to 34 patients with alcoholic liver disease (ALD), 25 patients with chronic viral liver disease and five normal biopsies. Sera were available from a total of 140 patients. The tritiated water released from the tritiated proline was measured in PH assessment. 14C intact and heat-denatured collagen substrates were used to measure collagenase and gelatinases, respectively. 3H Elastin was the substrate for elastase. In serum, ELISAs were used for MMP-1, TIMP-1, and TIMP-2 measurements while MMP-2 and MMP-9 were estimated by zymography. PH was significantly increased in early and late PBC. Collagenase was reduced only in the late stages (p &lt; 0.01), where the ratio PH/collagenase was increased. UDCA treatment restored values to almost normal. Gelatinases were reduced in late stages (p &lt; 0.05). In contrast to PBC and ALD fibrosis, collagen synthesis is not increased in viral fibrosis. The balance shifted towards collagen deposition due to reduced degradation. Interestingly, gelatinolytic activity is not impaired in ALD. Elastase was similar to controls in all diseases studied. TIMP-1 was reduced in early PBC and viral and alcoholic hepatitis and cirrhosis (p &lt; 0.001). (1) There is evidence that collagen synthesis increases in the early stages of PBC, but the collagenolytic mechanism may compensate for the increased synthesis. (2) In viral disease, fibrosis may be due to decreased degradation rather than increased synthesis. (3) The final biochemical stages of liver fibrosis may be quantitatively different according to underlying etiology.

Dietary curcumin supplementation can enhance health and resistance to ammonia stress in the greater amberjack (Seriola dumerili)

We evaluated the effect of dietary curcumin supplementation on the antioxidant capacity of the liver and the resistance of the liver and spleen to ammonia stress in the great amberjack (Seriola dumerili). Three isonitrogenous and isolipidic test diets were prepared by supplementing incremental levels of dietary curcumin at 0 mg/kg (CUR0%, control), 100 mg/kg (CUR0.01%), and 200 mg/kg (CUR0.02%), respectively. Each diet was randomly assigned to triplicate groups of 15 fish per tank. At the end of the feeding experiment, dietary curcumin supplementation positively modulated antioxidant-related genes and enzyme activity in liver tissues. After the ammonia challenge, dietary supplementation with the appropriate level of curcumin alleviated ammonia stress in liver tissue by upregulating the relative expression of GSH-Px and downregulating the relative expression of Keap1 and GR. Meanwhile, ammonia stress in spleen tissue could also be alleviated by upregulating the relative expression of CAT, downregulating the relative expression of GR, and increasing the activity of SOD and GSH. After the recovery, dietary supplementation with curcumin still alleviated ammonia stress in the liver tissue by upregulating the relative expression of CAT, downregulating the relative expression of Keap1 and GR, and increasing the activity of SOD and GSH. On the other hand, ammonia stress in spleen tissue was still alleviated by upregulating the relative expression of Mn-SOD and increasing the activity of SOD and GSH. The histological structure results also showed that liver cells in the curcumin-containing groups exhibited a positive impact on cell boundaries, alignment, and nuclei after the ammonia challenge and recovery. Spleen cells in the curcumin-containing groups exhibited greater aggregation of melano-macrophage centers after the ammonia challenge and recovery. These results suggest that dietary curcumin supplementation at 100 mg/kg can promote the health condition and resistance to ammonia stress of the greater amberjack.

Protective effects of Viscum album L. leaf extract on chlorpyrifos-induced hepatotoxicity in Wistar rats

ObjectivesThe goal of this study was to examine the antioxidant activity of Viscum album L. (VA, European mistletoe) extract (VAE) and to investigate whether VAE could provide protection against chlorpyrifos-induced hepatotoxicity. MethodsMale Wistar albino rats were divided into five groups and treated two times per week during four weeks: I group without treatment served as control; II, IV and V group were treated with chlorpyrifos (CPF, 35 mg/kg b.w) via gavage; III and IV group received a higher dose of VAE (350 mg/kg b.w); and V group received a lower dose of VAE (175 mg/kg b.w) intraperitoneally. The extract was obtained by ultrasound-assisted extraction. HPLC-DAD analysis was performed to investigate the chemical composition of the extract, and antioxidant assays to determine its antioxidant activities. Biochemical parameters, antioxidant enzyme activities in liver tissue, and histopathology were also determined. ResultsThe VAE caused significant decrease in glucose, TC, TG, albumins, AST, and ALT compared to CPF-treated rats. The cotreatment with VAE also significantly recovered the antioxidative system parameters (SOD, CAT, GSH-Px, GR, and GST) and alleviated some histopathological changes caused by CPF. ConclusionsOur data revealed that the simultaneous VAE administration modulated the negative changes induced by CPF. This study suggests that VAE could be useful in providing protection against hepatotoxicity and oxidative stress due to its antioxidative properties.

Assessment of antioxidant traits and protective action of Egyptian acacia pods extracts against paracetamol-induced liver toxicity in rats.

This study investigates the protective effect of Egyptian acacia pod extracts against overdose of paracetamol-induced liver damage. Egyptian acacia green and brown pods were extracted by mixture of ethanol 80%: HCl (6M) (99:1 v/v). In extracts of green and brown pods, total phenolic content in hydrolyzed ethyl acetate fraction (HEF) at pH 4, was 649.89 and 712.14mg GAE/g while antioxidant activity was 95.55% and 97.35%, both being the highest than any fraction. HEF (pH 4) in brown pods was analyzed by HPLC, there were 22 phenolic compounds rich in ethyl vanillin about 227mg/g and 11 flavonoids rich in catechin 48.70mg/g. A biological experiment was conducted using HEF (pH4) in brown pods against overdose of paracetamol in albino rats induced to hepatotoxicity. Thirty rats were divided into five groups; a control group, a paracetamol group, and the other three received paracetamol plus silymarin or two doses of HEF. Animals were received paracetamol and treated with either silymarin or HEF showed reduced levels of liver (ALT, AST, and ALP) and kidney (urea, creatinine, and uric acid) markers compared with the control group as well as reduction of oxidative stress and increment antioxidant enzyme activity in liver tissue when compared with the paracetamol group. It could be concluded that both HEF and silymarin are considerably high hepatoprotector against paracetamol-induced hepatotoxicity in rats due to their strong antioxidant activity. PRACTICAL APPLICATIONS: Both HEF and silymarin improved liver functions and exerted strong antioxidant activities. This antioxidant activity would have a positive effect against oxidative liver damage caused by parcetamol. Thus, it may be concluded that the liver plasma membranes were protected and the regenerative and reparative capacity of liver by phenolic compound in HEF treatment. The study demonstrated the HEF hepatoprotective activity and recommends using Egyptian acacia pods for treatment of liver disorders.

Oligosaccharide attenuates aging-related liver dysfunction by activating Nrf2 antioxidant signaling.

Chitosan oligosaccharide (COS) is the depolymerized product of chitosan possessing various biological activities and protective effects against inflammation and oxidative injury. The aim of the present study was to investigate the antioxidant effects of COS supplements on aging‐related liver dysfunction. We found that COS treatment significantly attenuated elevated liver function biomarkers and oxidative stress biomarkers and decreased antioxidative enzyme activities in liver tissues in D‐galactose (D‐gal)‐treated mice. Furthermore, COS treatment significantly upregulated the expression of Nrf2 and its downstream target genes HO‐1, NQO1, and CAT. Moreover, in vitro experiments showed that COS treatment played a vital role in protecting H2O2‐exposed L02 cells against oxidative stress by activating Nrf2 antioxidant signaling. These data indicate that COS could protect against D‐gal‐induced hepatic aging by activating Nrf2 antioxidant signaling, which may provide novel applications for the prevention and treatment of aging‐related hepatic dysfunction.

The effect of lycopene on hepatotoxicity of aflatoxin B1 in rats

Oxidative damage caused by aflatoxin (AF) in rat liver tissue and the inhibition effect of lycopene against this injury was investigated. Groups were formed as; control group (not treated), lycopene group (5 mg/kg/day, gavage for 15 days), AFB1 group (0.5 mg/kg/day, gavage for 7 days) and AFB1 + lycopene group. Lycopene administered simultaneously with AFB1. It was observed significant increase in malondialdehyde level, decrease in glutathione level, antioxidant enzyme activities in liver tissue of AFB1 group when compared with control group. It was determined to significantly increase in plasma aspartate transaminase, alanine transaminase, lactate dehydrogenase activities in AFB1 group when compared with control group. It was determined significant decrease in malondialdehyde level, plasma aspartate transaminase, alanine transaminase, lactate dehydrogenase activities and increase in glutathione level, antioxidant enzyme activities in AFB1 + lycopene group when compared with AFB1 group. This study suggests that lycopene which has antioxidant properties can be prevented from AFB1 induced hepatotoxicity.

Effects of Quercetin on Lipid and Protein Damage in the Liver of Streptozotocin-Induced Experimental Diabetic Rats.

Quercetin (QR) is part of a subclass of flavonoids called flavonols. We aimed to investigate the effect of QR on malondialdehyde (MDA), advanced oxidation protein products (AOPPs), and glutathione peroxidase (GSH-Px) activity in the liver of diabetic rats. We compared four groups of male adult Wistar albino rats: a control group, an untreated diabetic group, diabetic groups treated with QR, and QR group. Diabetes was induced by a single injection of streptozotocin (STZ) (50 mg/kg). Animals were kept in standard condition. On the 31st day of the study, the liver tissue was removed for biochemical parameters and histopathological evaluations. In an untreated diabetic group, liver MDA and AOPP levels were significantly higher than all groups. QR treatment significantly decreased the increased MDA, AOPP levels, and increased the decreased GSH-Px enzyme activity in liver tissues. The QR-treated rats in the diabetic group showed an improved histological appearance. Lesser vesicular vacuolization and fibrotic areas were observed in the QR-treated diabetic group than in the diabetic group. The STZ-induced liver injury is associated with oxidative stress, and coadministration of QR may reduce this damage effectively in a rat model. Our results are also supported by morphological improvement in liver tissue. Therefore, we think QR may be effective in treating hyperglycemia and oxidative damage in diabetes.

Polysaccharides from Phormidium versicolor (NCC466) protecting HepG2 human hepatocellular carcinoma cells and rat liver tissues from cadmium toxicity: Evidence from in vitro and in vivo tests

The in vitro antioxidant, cytotoxic and cytoprotective properties and in vivo hepatoprotective activities of crude polysaccharides extracted from cyanobacteria Phormidim versicolor NCC466 (CFv-PS) were investigated. The CFv-PS, identified as heteropolysaccharides with molecular weight of 63.79kDa, exhibited relatively strong antioxidant activity, in a concentration-depended manner, in vitro assays. Additionally, CFv-PS did not induce cytotoxic effect on HepG2 human hepatocellular carcinoma cells within the range of tested concentrations (25–150μg·mL−1) while preventing them against Cd. Moreover, in rats subjected to Cd-induced hepatotoxicity, CFv-PS pretreatment significantly (P<0.05) reduced the level of ALAT, ASAT, biliburin, MDA, protein carbonyl and DNA damage, and markedly increased enzyme activities in liver tissues. These findings suggest that the cyanobacteria Phormidium versicolor is a potential source of natural products possessing antioxidant, cytoprotective and hepatoprotective properties.

Phenanthrene-Induced Apoptosis and Its Underlying Mechanism.

Phenanthrene (Phe) is one of the most abundant low-molecular-weight polycyclic aromatic hydrocarbons (PAHs). Widespread human and aquatic organism exposure to Phe has been reported, but the toxic effects of Phe and potential mechanisms are unclear. We focused on the chronic hepatotoxicity of Phe in adult Chinese rare minnows (Gobiocypris rarus) and the underlying mechanisms. The chronic effects of exposing Chinese rare minnows to 8.9, 82.3, or 510.0 μg/L Phe for 30 days were examined by histopathological observation, TUNEL assays, caspase activity assays, and gene expression profiles. The liver lesion frequency and hepatocyte apoptosis were increased in Phe-exposed groups. Caspase 9 and caspase 3 enzyme activity in liver tissues was markedly increased. The expression of miR-17/92 cluster members was significantly increased in the 82.3 and 510.0 μg/L groups. Moreover, the response of primary hepatocytes indicated a significant decrease in the mitochondrial membrane potential (MMP) after a 48 h exposure to Phe. Interestingly, miR-18a was significantly decreased in primary hepatocytes in all treatments. Moreover, molecular docking indicated that Phe might have the same binding domain as pri-miR-18a, forming pi-pi and pi-σ interactions with heterogeneous nuclear ribonucleoprotein (hnRNP) A1. Given the above, Phe caused liver lesions and induced hepatocyte apoptosis through the intrinsic apoptosis pathway, and the interaction of Phe with hnRNP A1 contributes to the suppression of miR-18a expression and hepatocyte apoptosis.

Effects of copper oxide nanoparticles on antioxidant enzyme activities in liver tissue of Clarias gariepinus

This study aimed to determine the effects of dietary mixtures of aflatoxin B1 (AFB1) and fumonisin B1 (FB1) on growth performance and haematology of juvenile Clarias gariepinus and also determine the maximum tolerable limits for the mixture of these mycotoxins in C. gariepinus. Five experimental diets amended with varied concentrations of AFB1 and FB1 (Diet A (control 2.0 μg AFB1; 3.0 mg FB1/kg); Diet B (7.3 μg AFB1; 15.0 mg FB1/kg); Diet C (17.6 μg AFB1; 24.5 mg FB1/kg); Diet D (48.0 μg AFB1; 43.0 mg FB1/kg) and Diet E (93.0 μg AFB1; 83.0 mg FB1/kg were fed to 450 juvenile C. gariepinus catfish in five groups of 15 separate plastic tanks for a period or 56 days. Five fish were randomly sampled from each tank at time points day 7, 14, 28 and day 56. These fish were weighed, length measured and bleed for haematological determinations. Fish fed the diets amended with mixtures of AFB1 and FB1 exhibited significant reduction (p < 0.05) in growth performance marked by reduction in mean length gain; mean weight gain and specific growth rate compared to fish fed the control diets. Further, fish fed diets amended with mixtures of the mycotoxins showed significant reduction (p < .05) in the erythrocytes count, haemoglobin concentration and haematocrit compared to fish fed the control diet. Based on the results of growth and haematological performance, juvenile C. gariepinus can tolerate diets containing up to 17.6 μg AFB1/kg and 24.5 mg FB1/kg.

Polydatin alleviates alcohol-induced acute liver injury in mice: Relevance of matrix metalloproteinases (MMPs) and hepatic antioxidants

BackgroundAlcohol, a most commonly consumed beverage, is the foremost cause of liver injury throughout the world. Polydatin, a stilbenoid glucoside, was known to possess antioxidant and anti-inflammatory properties and is being investigated for use in various disorders. PurposeThe present study was intended at investigating the hepatoprotective efficacy of polydatin against acute-alcohol induced liver injury model in mice. Study designC57BL/6 mice were fed with five doses of 50% ethyl alcohol (10ml/kg body weight) to induce acute liver injury. Effect of polydatin against alcohol induced hepatic injury was investigated by giving 50 or 100mg/kg polydatin, orally, for 8 days. MethodsSerum markers of liver injury, morphology, histology and fibrosis of liver tissue, levels of enzymatic and non-enzymatic antioxidants and the mitochondrial respiratory enzyme activities in liver tissue were investigated. The activities and the protein expression of matrix metalloproteinases (MMP-2 and -9), the expression of NF-κB in the liver tissue were also studied. ResultsPolydatin pre-treatment significantly alleviated the alcohol induced hepatic injury by reducing the serum liver injury markers, alanine aminotransferase (ALT) and aspartate aminotransferase (AST), attenuating oxidative stress and restoring antioxidant balance in the hepatic tissue. Simultaneously, polydatin pre-treatment also prevented alcohol induced mitochondrial damage and refurbished the matrix metalloproteinases levels of the hepatic tissue. ConclusionThe findings of the present study suggest that polydatin may have a potential benefit in preventing alcohol-induced acute hepatic injury.

Hepatoprotective activity of total iridoid glycosides isolated from Paederia scandens (lour.) Merr. var. tomentosa

Ethnopharmacological relevanceCurrently, human liver is susceptible to injury caused by alcohol and virus infiltration, resulting in hepatitis, cirrhosis, and even hepatocellular carcinoma. Paederia scandens (Lour.) Merr. var. tomentosa (Rubiaceae) has been used as traditional medicine in Asian countries to treat jaundice, dysentery, and abdominal mass. Furthermore, the abundance of iridoid glycosides in Paederia species indicates their notable hepatoprotective potential. Materials and methodsTotal iridoid glycosides (TG) was prepared, and constituents of TG were analyzed by HPLC. TG and silymarin (positive) were orally administered for 15 days. Then, acute liver injury rats was induced by intraperitoneally injection (i.p.) of 10% CCl4 (0.12%, v/v, dissolved in olive oil, 10mL/kg, body weight). Rats were sacrificed at 16h after CCl4 injection. Liver tissues and blood were collected. Serum samples were prepared to determine the activities of alanine transaminase (ALT) and aspartate transaminase (AST), whereas liver tissue sections were prepared for the purpose of examining possible liver histopathological changes. In addition, antioxidant enzyme activities in liver tissues were also evaluated. ResultsOur results demonstrated that TG significantly decreased the levels of AST and ALT, compared with those in control rats. In addition, pre-treatment of the rats with TG clearly alleviated their liver tissue injuries. What’s more, the activities of GSH, GAT and SOD in the groups of TG-treated rats were significantly increased compared with those of rats in the control group, whereas the levels of MDA were decreased. ConclusionsOur present research indicated that TG possessed notable hepatoprotective activity via decreasing oxidative stress level in liver tissues.

Effects of Eriobotrya japonica seed extract on oxidative stress in rats with non-alcoholic steatohepatitis

Non-alcoholic steatohepatitis is associated with the deposition of lipid droplets in the liver, and is characterised histologically by the infiltration of inflammatory cells, hepatocellular degeneration and liver fibrosis. Oxidative stress may play an important role in the onset and deterioration of non-alcoholic steatohepatitis. We previously reported that an Eriobotrya japonica seed extract, extracted in 70% ethanol, exhibited antioxidant actions in vitro and in vivo. In this study, we examined the effect of this extract in a rat model of non-alcoholic steatohepatitis. The seed extract was given in the drinking water to fats being fed a methionine-choline-deficient diet for 15 weeks. Increases in alanine aminotransferase and aspartate aminotransferase levels were significantly inhibited in rats fed the seed extract compared with the group on the diet alone. Formation of fatty droplets in the liver was also inhibited. Antioxidant enzyme activity in liver tissue was higher than in the diet-only group and lipid peroxidation was reduced compared with rats that also received the extract. Expression of 8-hydroxy-2'-deoxyguanosine and 4-hydroxy-2-nonenal was lower in the rats given the seed extract than in the diet-only group. In the former, liver tissue levels of transforming growth factor-beta and collagen were also decreased. Thus, the E. japonica seed extract inhibited fatty liver, inflammation and fibrosis, suggesting its usefulness in the treatment of non-alcoholic steatohepatitis.

Laparoscopic liver biopsy using cup-shaped punch biopsy forceps and argon beam coagulator in children

Needle liver biopsy is insufficient for measuring enzyme activity in liver tissue in child cases of intrahepatic cholestasis because the biopsy specimen obtained is too small. This study was undertaken to validate the feasibility of a new, relatively non-invasive laparoscopic liver biopsy technique combining the use of laparoscopic cup-shaped punch biopsy forceps (CPBF) and an argon beam coagulator (ABC) handpiece for the diagnosis and examination of liver enzyme activity in cases of intrahepatic cholestasis in children. The authors performed laparoscopic liver biopsy with the combined use of laparoscopic CPBF and an ABC handpiece in 10 children aged 4 months to 9 years old. Two 5-mm trocars were inserted in each patient after their abdomens had been filled with carbon dioxide gas at a pressure of 8 mmHg. Four to five specimens (each: 0.5 cm(3) in size) were taken at the anterior edge of the left lobe of the liver using laparoscopic CPBF. ABC was sprayed on to the cut liver surface to achieve hemostasis. The duration of the laparoscopic procedure ranged from 25 to 64 (44 +/- 12.8) min. The maximum intraoperative hemorrhage from the biopsied liver bed was 30 ml. The bleeding was easily controlled using ABC for about 1 min. There were no cases of postoperative bleeding, bile leakage from the cut surface, nor intraabdominal infection. There were also no death cases, and only one complication (hydrocele testis) was recorded. Examination by microscopy and assays of enzyme activities were performed using these biopsy specimens, which were sufficient for diagnosis in all patients. Laparoscopic liver biopsy combining the use of laparoscopic CPBF and an ABC handpiece can be performed safely, is less invasive, and provides sufficient samples for examination both by microscopy and enzyme activity assays.

Transient Hyperammonemia Due to Urea Cycle Enzyme Deficiency in Irish Wolfhounds

Background:Irish Wolfhounds frequently have a congenital portosystemic shunt, but a considerable proportion of the 6‐to 8‐wk‐old pups has hyperammonemia in the absence of portosystemic shunting. This hyperammonemia causes no signs and is transient, normalizing at the age of 3–4 months.Hypothesis:Transient hyperammonemia has a metabolic basis in Irish Wolfhounds.Animals:Two related (same sire) litters of Irish Wolfhounds (17 pups) and their parents were studied.Methods:Integrity of the portal circulation was examined by ultrasonography and scintigraphy. Absence of parenchymal liver disease was verified by liver biopsy. Amino acid profiles were measured in 4 pups and repeated in 2 of these pups when ammonia concentrations had normalized. The amino acid profiles were compared with those of healthy Irish Wolfhound pups.Results:Fasting venous ammonia concentrations were high (113–622 μg/dL, 65–345 μmol/L) in all pups, whereas bile acids were within reference range in all but 1. The ammonia and bile acid concentrations from all parents were within reference range. Portosystemic shunting was excluded in all but 1 pup. Liver biopsy excluded significant lesions in all 10 pups examined. Hypercitrullinemia was found and persisted even when ammonia had normalized, at the expense of an increase in glutamine and asparagine.Conclusions and Clinical Importance: Citrulline concentrations are controlled by the urea cycle enzymes argininosuccinase and argininosuccinate synthetase, and a defect in either of these enzymes may be responsible for the transient hyperammonemia in Irish Wolfhounds. Resolution of the hyperammonemia is associated with increased activity of alternative metabolic pathways forming glutamine and asparagine. Confirmation requires measurement of enzyme activities in liver tissue.

Transient Hyperammonemia Due to Urea Cycle Enzyme Deficiency in Irish Wolfhounds

Irish Wolfhounds frequently have a congenital portosystemic shunt, but a considerable proportion of the 6- to 8-wk-old pups has hyperammonemia in the absence of portosystemic shunting. This hyperammonemia causes no signs and is transient, normalizing at the age of 3-4 months. Transient hyperammonemia has a metabolic basis in Irish Wolfhounds. Two related (same sire) litters of Irish Wolfhounds (17 pups) and their parents were studied. Integrity of the portal circulation was examined by ultrasonography and scintigraphy. Absence of parenchymal liver disease was verified by liver biopsy. Amino acid profiles were measured in 4 pups and repeated in 2 of these pups when ammonia concentrations had normalized. The amino acid profiles were compared with those of healthy Irish Wolfhound pups. Fasting venous ammonia concentrations were high (113-622 microg/dL, 65-345 micromol/L) in all pups, whereas bile acids were within reference range in all but 1. The ammonia and bile acid concentrations from all parents were within reference range. Portosystemic shunting was excluded in all but 1 pup. Liver biopsy excluded significant lesions in all 10 pups examined. Hypercitrullinemia was found and persisted even when ammonia had normalized, at the expense of an increase in glutamine and asparagine. Citrulline concentrations are controlled by the urea cycle enzymes argininosuccinase and argininosuccinate synthetase, and a defect in either of these enzymes may be responsible for the transient hyperammonemia in Irish Wolfhounds. Resolution of the hyperammonemia is associated with increased activity of alternative metabolic pathways forming glutamine and asparagine. Confirmation requires measurement of enzyme activities in liver tissue.

Enzymatically Active N-Deacetylase/N-Sulfotransferase-2 Is Present in Liver but Does Not Contribute to Heparan Sulfate N-Sulfation

Heparan sulfate (HS) proteoglycans influence embryonic development through interactions with growth factors and morphogens. The interactions depend on HS structure, which is largely determined during biosynthesis by Golgi enzymes. NDST (glucosaminyl N-deacetylase/N-sulfotransferase), responsible for HS N-sulfation, is a key enzyme directing further modifications including O-sulfation. To elucidate the roles of the different NDST isoforms in HS biosynthesis, we took advantage of mice with targeted mutations in NDST1 and NDST2 and used liver as our model organ. Of the four NDST isoforms, only NDST1 and NDST2 transcripts were shown to be expressed in control liver. The absence of NDST1 or NDST2 in the knock-out mice did not affect transcript levels of other NDST isoforms or other HS modification enzymes. Although the sulfation level of HS synthesized in NDST1-/- mice was drastically lowered, liver HS from wild-type mice, from NDST1+/-, NDST2-/-, and NDST1+/- / NDST2-/- mice all had the same structure despite greatly reduced NDST enzyme activity (30% of control levels in NDST1+/- / NDST2-/- embryonic day 18.5 embryos). Enzymatically active NDST2 was shown to be present in similar amounts in wild-type, NDST1-/-, and NDST1+/- embryonic day 18.5 liver. Despite the substantial contribution of NDST2 to total NDST enzyme activity in embryonic day 18.5 liver (approximately 40%), its presence did not appear to affect HS structure as long as NDST1 was also present. In NDST1-/- embryonic day 18.5 liver, in contrast, NDST2 was responsible for N-sulfation of the low sulfated HS. A tentative model to explain these results is presented.