The Extraction of Liver Glycogen Molecules for Glycogen Structure Determination.

Liver glycogen is a hyperbranched glucose polymer that is involved in the maintenance of blood sugar levels in animals. The properties of glycogen are influenced by its structure. Hence, a suitable extraction method that isolates representative samples of glycogen is crucial to the study of this macromolecule. Compared to other extraction methods, a method that employs a sucrose density gradient centrifugation step can minimize molecular damage. Based on this method, a recent publication describes how the density of the sucrose solution used during centrifugation was varied (30%, 50%, 72.5%) to find the most suitable concentration to extract glycogen particles of a wide variety of sizes, limiting the loss of smaller particles. A 10 min boiling step was introduced to test its ability to denature glycogen degrading enzymes, thus preserving glycogen. The lowest sucrose concentration (30%) and the addition of the boiling step were shown to extract the most representative samples of glycogen.

Ethanol extract of mulberry leaves partially restores the composition of intestinal microbiota and strengthens liver glycogen fragility in type 2 diabetic rats.

BACKGROUND: Mulberry leaf as a traditional Chinese medicine is able to treat obesity, diabetes, and dyslipidemia. It is well known that diabetes leads to intestinal microbiota dysbiosis. It is also recently discovered that liver glycogen structure is impaired in diabetic animals. Since mulberry leaves are able to improve the diabetic conditions through reducing blood glucose level, it would be interesting to investigate whether they have any positive effects on intestinal microbiota and liver glycogen structure. METHODS: In this study, we first determined the bioactive components of ethanol extract of mulberry leaves via high-performance liquid chromatography (HPLC) and liquid chromatography/mass spectrometry (LC/MS). Murine animal models were divided into three groups, normal Sprague-Dawley (SD) rats, high-fat diet (HFD) and streptozotocin (STZ) induced type 2 diabetic rats, and HFD/STZ-induced rats administered with ethanol extract of mulberry leaves (200 mg/kg/day). Composition of intestinal microbiota was analyzed via metagenomics by sequencing the V3-V4 region of 16S rDNAs. Liver glycogen structure was characterized through size exclusion chromatography (SEC). Both Student's t-test and Tukey's test were used for statistical analysis. RESULTS: A group of type 2 diabetic rat models were successfully established. Intestinal microbiota analysis showed that ethanol extract of mulberry leaves could partially change intestinal microbiota back to normal conditions. In addition, liver glycogen was restored from fragile state to stable state through administration of ethanol extract of mulberry leaves. CONCLUSIONS: This study confirms that the ethanol extract of mulberry leaves (MLE) ameliorates intestinal microbiota dysbiosis and strengthens liver glycogen fragility in diabetic rats. These finding can be helpful in discovering the novel therapeutic targets with the help of further investigations.

Effect of nano yam polysaccharide on the blood glucose and blood lipid in rats.

Chinese yam is the dry rhizome of dioscoreaceae plant. Polysaccharide in yam is one of significant functional components, its pharmacological effects include glucose-lowering, lipid-lowering, anti-tumor, anti-oxidation and enhancing the immune. The effects of nano yam polysaccharide on the metabolism of blood glucose and blood lipid in model rats were systematically investigated in this study. The results showed that the diabetic rat model can been successfully induced by the peritoneal injection of 200mg/kg alloxan. The rats were fed with the high-fat diet for 30d, which could induce a model of hyperlipidemia rat successfully. After the model rats were fed with nano yam polysaccharide of 50mg/ml and 100mg/ml per day for 12d and 30d, respectively. For each nano yam polysaccharide group, the blood glucose level was significantly reduced, the glucose tolerance, glycogen and the content of C-peptide were improved in alloxan rats. Moreover, the symptom of one little and three more in diabetic rats was ameliorated and the contents of TC, TG and LDL-C in the serum for the high fat rats were significantly decreased.

Resveratrol does not affect leptin while it has regulatory effects on liver glycogen levels in exercised and non-exercised rats.

Resveratrol (RES) is a well-known phytocompound and food component which has antioxidative and multifunctional bioactivities. The present study aims to examine how resveratrol administration affects plasma leptin and liver glycogen levels in rats subjected to an acute swimming exercise bout. The study was carried out on Wistar-Albino type adult male rats, each group include 7 rats. Group 1, Control Group. Group 2, Control Swimming Group: The group fed on a standard diet and subjected to an acute swimming exercise bout for 30 minutes at the end of the study. Group 3, Resveratrol Group: The group fed on a standard diet and given (10 mg/kg) resveratrol in drinking water for four weeks. Group 4, Resveratrol + Swimming Group: The group fed on a standard diet, given (10 mg/kg) resveratrol in drinking water for four weeks and subjected to a 30-minute acute swimming exercise at the end of the study. Plasma leptin levels using ELISA method (ng/l) and liver glycogen levels were determined by using histochemical method (number/0.1 mm2). Four weeks resveratrol administration to exercised and not-exercised rats did not cause a change in plasma leptin levels. Liver glycogen levels were 17.00 ± 3.16; 14.12 ± 2.98; 20.82 ± 1.97; 16.38 ± 1.27 (mean ± sd); respectively in groups 1, 2, 3, 4. Resveratrol administration to rats subjected to a bout of acute swimming exercise produced an effect that prevented the decrease in liver glycogen (p < 0.05). The study highlights that resveratrol supplementation may have regulatory effects on liver glycogen levels in exercised and non-exercised rats.

Post-Stress Fructose and Glucose Ingestion Exhibit Dissociable Behavioral and Physiological Effects.

An acute traumatic event can lead to lifelong changes in stress susceptibility and result in psychiatric disease such as Post-Traumatic Stress Disorder (PTSD). We have previously shown that access to a concentrated glucose solution for 24 hours beginning immediately after trauma decreased stress-related pathology in the learned helplessness model of PTSD and comorbid major depression. The current study sought to investigate the peripheral physiological effects of post-stress glucose consumption. We exposed 128 male Sprague-Dawley rats to inescapable and unpredictable 1-milliamp electric tail shocks or simple restraint in the learned helplessness procedure. Rats in each stress condition had access to a 40% glucose solution, 40% fructose solution, or water. Blood and liver tissue were extracted and processed for assay. We assessed corticosterone, corticosteroid-binding globulin (CBG), glucose, and liver glycogen concentrations at various time points following stress. We found that rats given access to glucose following exposure to traumatic shock showed a transient rise in blood glucose and an increase in liver glycogen repletion compared to those that received water or fructose following exposure to electric shock. We also found that animals given glucose following shock exhibited reduced free corticosterone and increased CBG compared to their water-drinking counterparts. However, this difference was not apparent when glucose was compared to fructose. These data suggest that post-stress glucose prophylaxis is likely not working via modulation of the HPA axis, but rather may provide its benefit by mitigating the metabolic challenges of trauma exposure.

Antisense Inhibition of Glucagon Receptor by IONIS-GCGRRx Improves Type 2 Diabetes Without Increase in Hepatic Glycogen Content in Patients With Type 2 Diabetes on Stable Metformin Therapy.

OBJECTIVE: To evaluate the safety and efficacy of IONIS-GCGRRx, a 2'-O-methoxyethyl antisense oligonucleotide targeting the glucagon receptor (GCGR), and the underlying mechanism of liver transaminase increases in patients with type 2 diabetes on stable metformin therapy. RESEARCH DESIGN AND METHODS: In three phase 2, randomized, double-blind studies, patients with type 2 diabetes on metformin received weekly subcutaneous injections of IONIS-GCGRRx (50-200 mg) or placebo for 13 or 26 weeks. RESULTS: Significant reductions in HbA1c were observed after IONIS-GCGRRx treatment versus placebo at week 14 (-2.0% 200 mg, -1.4% 100 mg, -0.3% placebo; P < 0.001) or week 27 (-1.6% 75 mg, -0.9% 50 mg, -0.2% placebo; P < 0.001). Dose-dependent increases in transaminases were observed with IONIS-GCGRRx, which were attenuated at lower doses and remained mostly within the normal reference range at the 50-mg dose. There were no other significant safety observations and no symptomatic hypoglycemia or clinically relevant changes in blood pressure, LDL cholesterol, or other vital signs. At week 14, IONIS-GCGRRx 100 mg did not significantly affect mean hepatic glycogen content compared with placebo (15.1 vs. -20.2 mmol/L, respectively; P = 0.093) but significantly increased hepatic lipid content (4.2 vs. -2.7%, respectively; P = 0.005) in the presence of transaminase increases. CONCLUSIONS: IONIS-GCGRRx is a potent inhibitor of hepatic glucagon receptor expression with a potential to improve glycemic control at low weekly doses in combination with metformin. Significant reductions in HbA1c occurred across the full-dose range tested, with minimal transaminase elevations at lower doses. Furthermore, novel results suggest that despite inhibition of glycogenolysis after GCGR antagonism, IONIS-GCGRRx did not increase hepatic glycogen content.

Effects of Sideritis scardica Extract on Glucose Tolerance, Triglyceride Levels and Markers of Oxidative Stress in Ovariectomized Rats.

Menopause is characterized by deep metabolic disturbances, including decreased insulin sensitivity, adiposity, and changes in lipid profiles. Estrogen replacement therapy can partially reverse these changes, and while it is safe in most healthy postmenopausal women, there are still existing concerns regarding an increased risk for breast and endometrial cancer as well as a risk for cardiovascular and thromboembolic disease. Therefore, certain natural compounds with positive metabolic effects may be considered as a possible alternative or adjunctive treatment in patients not willing to take estrogens or patients with contraindications for estrogens. The aim of this study was to investigate the influence of Sideritis scardica (mountain tea) extract on metabolic disturbances induced by ovariectomy in rats. The study included 24 rats divided into three groups: ovariectomized rats treated with 200 mg/kg S. scardica extract for 24 weeks (n = 8), ovariectomized non-treated (n = 8), and Sham-operated (n = 8) rats. Food intake, weight gain, body composition, fasting glucose levels, response to oral glucose challenge, liver glycogen content, catalase activity, thiol groups, and malondialdehyde concentrations as well as AMP-activated protein kinase activity in liver cells were studied. Ovariectomized rats treated with S. scardica extract had lower blood triglycerides, reduced fasting glucose levels, as well lower glucose peaks after oral glucose challenge, increased liver glycogen content, and significantly higher catalase activity and thiol group concentration than non-treated ovariectomized rats. The ability of S. scardica extract to attenuate metabolic disturbances associated with ovariectomy was associated with the activation of AMP-activated protein kinase in liver cells.

Ginger and vitamin C as protective agents against oxidative stress and liver injury induced by methyl parathion

Methyl parathion is one of the highly toxic organophosphorus (OP) compounds. It induces hepatotoxicity, which might be related to generation of reactive oxygen species. This study was carried out to investigate the protective roles of vitamins C and ginger against hepatotoxicity induced by methyl parathion in male albino rats.Sixty male albino rats were randomly divided into 6 groups (ten rats each). Group I was considered as controls. Animals of groups II, III and IV were given methyl parathion (2 mg/kg), ginger (200 mg/kg) and vitamin C (100 mg/kg) respectively. Groups V and VI were given ginger (200 mg/kg) and vitamin C (100 mg/kg) respectively 2 hours before methyl parathion administration. All animals were treated orally, once daily, for four weeks. Blood and liver samples were obtained for biochemical, immunohistochemistry and histopathological examinations.Administration of either ginger or vitamin C along with methyl parathion significantly reduced the alanine aminotransferase (ALT) and malondialdehyde (MDA) levels in rats compared to those only treated with methyl parathion. Treatment with either ginger or vitamin C in combination with methyl parathion resulted in increased level of reduced glutathione compared to the methyl parathion treated group. However, oral ginger significantly increased glutathione-S-transferase levels compared to the control group, and this may outbalance the protective value of ginger over vitamin C to guard against liver injury and oxidative stress. The immunohistochemical and histopathological examinations showed that ginger or vitamin C combination with methyl parathion resulted in less hepatocytes degeneration and milder portal tract infiltration compared to the methyl parathion group.In conclusion, pre-treatment with either ginger or vitamin C appears to alleviate methyl parathion-inducted hepatotoxicity. However, their protective role is still limited and needs further investigation

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Liraglutide Decreases Hepatic Inflammation and Injury in Advanced Lean Non-Alcoholic Steatohepatitis.

Although commonly associated with obesity, non-alcoholic fatty liver disease (NAFLD) is also present in the lean population representing a unique disease phenotype. Affecting 25% of the world's population, NAFLD is associated with increased mortality especially when progressed to non-alcoholic steatohepatitis (NASH). However, no approved pharmacological treatments exist. Current research focuses mainly on NASH associated with obesity, leaving the effectiveness of promising treatments in lean NASH virtually unknown. This study therefore aimed to evaluate the effect of liraglutide (glucagon-like peptide 1 analogue) and dietary intervention, alone and in combination, in guinea pigs with non-obese NASH. After 20 weeks of high-fat feeding (20% fat, 15% sucrose, 0.35% cholesterol), 40 female guinea pigs were block-randomized based on weight into four groups receiving one of four treatments for 4 weeks: continued high-fat diet (HF, control), high-fat diet and liraglutide treatment (HFL), chow diet (4% fat, 0% sucrose, 0% cholesterol; HFC) or chow diet and liraglutide treatment (HFCL). High-fat feeding induced NASH with severe fibrosis. Liraglutide decreased inflammation (p < 0.05) and hepatocyte ballooning (p < 0.05), while increasing hepatic α-tocopherol (p = 0.0154). Dietary intervention did not improve liver histopathology significantly, but decreased liver weight (p = 0.004), plasma total cholesterol (p = 0.0175), LDL-cholesterol (p = 0.0063), VLDL-cholesterol (p = 0.0034), hepatic cholesterol (p < 0.0001) and increased hepatic vitamin C (p = 0.0099). Combined liraglutide and dietary intervention induced a rapid weight loss, necessitating periodical liraglutide dose adjustment/discontinuation, limiting the strength of the findings from this group. Collectively, this pre-clinical study supports the beneficial effect of liraglutide on NASH and extends this notion to lean NASH.

Sarcopoterium spinosum extract improved insulin sensitivity in mice models of glucose intolerance and diabetes.

BACKGROUND: The glucose lowering properties of Sarcopoterium spinosum, a traditional medicinal plant, were previously validated by us using KK-Ay mice as a genetic model for type 2 diabetes (T2D). OBJECTIVE: To clarify the effects of Sarcopoterium spinosum extract (SSE) on diet-induced glucose intolerance and to investigate SSE effects on carbohydrate and lipid metabolism in target tissues of both high-fat-diet (HFD)-fed and KK-Ay mice. RESULTS: Mice were given SSE (70 mg/day) for 6 weeks. SSE improved glucose tolerance and insulin sensitivity in HFD-fed mice as was demonstrated previously in KK-Ay mice. Higher insulin sensitivity was validated by lower serum insulin and activation of the insulin signaling cascade in skeletal muscle and liver of SSE-treated mice in both models. H&E staining of the livers demonstrated lower severity of steatosis in SSE-treated mice. Several model-specific effects of SSE were observed-mRNA expression of proinflammatory genes and CD36 was reduced in SSE-treated KK-Ay mice. Hepatic mRNA expression of PEPCK was also reduced in SSE-treated KK-Ay mice, while other genes involved in carbohydrates and lipid metabolism were not affected. HFD-fed mice treated by SSE had elevated hepatic glycogen stores. Gluconeogenic gene expression was not affected, while GCK expression was increased. HFD-induced hepatic steatosis was not affected by SSE. However, while genes involved in lipid metabolism were downregulated by HFD, this was not found in HFD-fed mice given SSE, demonstrating an expression profile which is similar to that of standard diet-fed mice. CONCLUSION: Our study supports the insulin sensitizing activity of SSE and suggests that this extract might improve other manifestations of the metabolic syndrome.

Relationship between genetic variation at PPP1R3B and levels of liver glycogen and triglyceride.

Genetic variation at rs4240624 on chromosome 8 is associated with an attenuated signal on hepatic computerized tomography, which has been attributed to changes in hepatic fat. The closest coding gene to rs4240624, PPP1R3B, encodes a protein that promotes hepatic glycogen synthesis. Here, we performed studies to determine whether the x-ray attenuation associated with rs4240624 is due to differences in hepatic glycogen or hepatic triglyceride content (HTGC). A sequence variant in complete linkage disequilibrium with rs4240624, rs4841132, was genotyped in the Dallas Heart Study (DHS), the Dallas Liver Study, and the Copenhagen Cohort (n = 112,428) of whom 1,539 had nonviral liver disease. The minor A-allele of rs4841132 was associated with increased hepatic x-ray attenuation (n = 1,572; P = 4 × 10-5 ), but not with HTGC (n = 2,674; P = 0.58). Rs4841132-A was associated with modest, but significant, elevations in serum alanine aminotransferase (ALT) in the Copenhagen Cohort (P = 3 × 10-4 ) and the DHS (P = 0.004), and with odds ratios for liver disease of 1.13 (95% CI, 0.97-1.31) and 1.23 (1.01-1.51), respectively. Mice lacking protein phosphatase 1 regulatory subunit 3B (PPP1R3B) were deficient in hepatic glycogen, whereas HTGC was unchanged. Hepatic overexpression of PPP1R3B caused accumulation of hepatic glycogen and elevated plasma levels of ALT, but did not change HTGC. CONCLUSION: These observations are consistent with the notion that the minor allele of rs4841132 promotes a mild form of hepatic glycogenosis that is associated with hepatic injury. (Hepatology 2018;67:2182-2195).

Adrenergic regulation during acute hepatic infection with Entamoeba histolytica in the hamster: involvement of oxidative stress, Nrf2 and NF-KappaB.

Oxidative stress and transcriptional pathways of nuclear factor erythroid 2-related factor 2 (Nrf2) and nuclear factor kappa-B (NF-κB) are critically involved in the etiopathology of amebic liver abscess (ALA). In this work, we studied the relationship between the adrenergic nervous system and ALA in the hamster. ALA was visible at 12 h of infection. While 6-hydroxidopamine (6-OHDA) decreased infection, propranolol (ß-adrenergic blocker) treatment was associated with less extensive liver damage, and phentolamine treatment (α-adrenergic blocker) significantly reduced ALA compared to 6-OHDA and propranolol. Serum enzymatic activities of alanine aminotransferase (ALT) and γ-glutamyl transpeptidase (γ-GTP) were increased at 12 h post-infection. Chemical denervation and α and ß-adrenergic blockers decreased ALT to normal levels, while 6-OHDA and propranolol showed a trend to decrease γ-GTP but phentolamine significantly reduced γ-GTP. Amebic infection increased oxidized glutathione (GSSG) and decreased both reduced glutathione (GSH) and the GSH/GSSG ratio. Propranolol and 6-OHDA showed a tendency to decrease GSSG. However, GSH, GSSG and GSH/GSSG returned to normal levels with phentolamine. Furthermore, amebic infection increased pNF-κB and interleukin-1ß (IL-1ß), and showed a tendency to decrease hemoxigenase-1 (HO-1), but not Nrf2. Chemical denervation showed a trend to decrease pNF-κB and IL-1ß, and neither Nrf2 nor HO-1 increased significantly. In addition, NF-κB and IL-1ß were attenuated by propranolol and phentolamine treatments, although phentolamine showed significant overexpression of Nrf2 and HO-1. This suggests that the adrenergic system may be involved in oxidative stress and in modulation of the Nrf2 and NF-κB pathways during ALA development.

Glycogenic hepatopathy in young adults: a case series

Glycogenic hepatopathy is a rare and underecognized complication in long-standing poorly controlled type 1 diabetes mellitus patients. This is a distinct entity from other causes of hepatomegaly and elevated liver enzymes in diabetics, such as nonalcoholic fatty liver disease. Glycogenic hepatopathy is characterized by the combination of poorly controlled diabetes, acute liver injury with marked elevation in serum aminotransferases, and the characteristic histological features on liver biopsy. It is important to distinguish this entity as it has the potential for resolution following improved glycemic control. In this report, we describe four cases of adult patients presenting elevated serum transaminases and hepatomegaly with a history of poorly controlled type I diabetes mellitus. One of the patients had also elevated amylase and lipase in the serum, without clinical or imagiologic evidence of acute pancreatitis. Liver biopsy was performed in all patients and revealed glycogenic hepatopathy. Clinician’s awareness of glycogenic hepatopathy should prevent diagnostic delay or misdiagnosis and will provide better insight and management for this condition (AU)

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Visualization of acetaminophen-induced liver injury by time-of-flight secondary ion mass spectrometry.

Time-of-flight secondary ion mass spectrometry (MS) provides secondary ion images that reflect distributions of substances with sub-micrometer spatial resolution. To evaluate the use of time-of-flight secondary ion MS to capture subcellular chemical changes in a tissue specimen, we visualized cellular damage showing a three-zone distribution in mouse liver tissue injured by acetaminophen overdose. First, we selected two types of ion peaks related to the hepatocyte nucleus and cytoplasm using control mouse liver. Acetaminophen-overdosed mouse liver was then classified into three areas using the time-of-flight secondary ion MS image of the two types of peaks, which roughly corresponded to established histopathological features. The ion peaks related to the cytoplasm decreased as the injury became more severe, and their origin was assumed to be mostly glycogen based on comparison with periodic acid-Schiff staining images and reference compound spectra. This indicated that the time-of-flight secondary ion MS image of the acetaminophen-overdosed mouse liver represented the chemical changes mainly corresponding to glycogen depletion on a subcellular scale. In addition, this technique also provided information on lipid species related to the injury. These results suggest that time-of-flight secondary ion MS has potential utility in histopathological applications.

Characterization and improvement of phenol-sulfuric acid microassay for glucose-based glycogen.

OBJECTIVES: Phenol-sulfuric acid reagent is used to measure the concentration of glyco-polymers and -conjugates. There are several uncertainties on glycogen measurement in the tissues. We aimed to improve phenol-sulfuric reagent for microassay of glucose based-glycogen in small tube or microplate. MATERIALS AND METHODS: The condition of the reaction was optimized and scaled down for both small tube and microplate application. RESULTS: The color intensity was found to be a function of all components of the assay mixture, that is, the amount of sugar and phenol together with the volume of total water and acid. The absorbance increased in the range of 4-10 mg of phenol and reached the plateau between 10-16 mg per 1 mL of acid. The color intensity was a linear function of total water volume (sugar-water- phenol). The sensitivity increased eight times as total water volume was changed from 50 up to 400 µL. The curve for acid volume peaked at about 1 mL. The optimal assay condition was determined to be 13 mg of phenol (200 µL 6.5%), 400-425 µL of total water volume (100 µL of sugar, 100 µL water) for 1 mL of acid. The initial spontaneous high temperature is essential the reaction to proceed and any handling gives inconsistent results and decreases the precision and sensitivity of the method. The values were scaled down by a factor of 0.5 for tube application and reading in cuvet or microplate and by 0.2 or 0.15 for microplate application. CONCLUSIONS: The results indicated that phenol-sulfuric acid reagent could be scaled down to 1.0, 0.5 and 0.20, 0.15 mL of sulfuric acid for microassay of glucose based-glycogen.

Antioxidant and anti-fatigue activities of egg white peptides prepared by pepsin digestion.

BACKGROUND: Some hydrolyzed peptides derived from food proteins possess antioxidant and anti-fatigue activities. In this study, egg white protein powder (EWPP) was hydrolyzed with pepsin for various times, and four peptide fractions were separated from the hydrolysates by ultrafiltration. The antioxidant activity of the four peptide fractions was determined. The peptide fraction with the strongest antioxidant activity was used to evaluate its anti-fatigue effect and probable mechanisms. RESULTS: The egg white peptides (EWPs) fraction with molecular weight 2-5 kDa (named EWPs2) showed stronger antioxidant activity than the other peptide fractions (P < 0.05). The swimming time to exhaustion of mice administered EWPs2 was longer (P < 0.05) than that of the control group. EWPs2 increased the levels of blood glucose (by 28.4-42.2%), muscle glycogen (by 6.4-10.6%) and liver glycogen (by 10.7-23.8%) and significantly decreased the levels of lactic acid in muscle and urea nitrogen in blood (P < 0.05). CONCLUSION: Among the four peptide fractions, EWPs2 possessed the strongest antioxidant activity and exhibited an anti-fatigue effect. The experimental data could clarify partially the anti-fatigue mechanisms of EWPs and provide an important basis for developing EWPs as safe and natural antioxidants and anti-fatigue agents for wide use.

Metabolic and histopathological profile of Rattus norvegicus (Wistar) experimentally infected by Angiostrongylus cantonensis (Chen, 1935).

Eosinophilic meningitis is a disease characterized by increased eosinophils in the cerebrospinal fluid (CSF), which is the most commonly caused by invasion of the central nervous system by helminths, as occurs in Angiostrongylus cantonensis infections. The rodent Rattus norvegicus is the definitive natural host and humans act as accidental hosts and can become infected by eating raw or undercooked snails or food contaminated with infective L3 larvae. Recently in Brazil there have been four cases of eosinophilic meningitis due to ingestion of infected Achatina fulica. To evaluate biochemical and histopathological changes caused by this parasite, R. norvegicus were experimentally infected with 100 L3 larvae of A. cantonensis. After the anesthetic procedure, serum from the rodents was collected from the inferior vena cava for evaluation of the levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALKP), gamma-glutamyl transferase (GGT), total protein and its fractions. During the necropsy, the liver was collected and weighed. Then a 1-g fragment was extracted from the major lobe to quantify the hepatic glycogen and fragment remainder was taken from the same lobe and fixed in Milloning's formalin for histopathological examination. Additionally, helminths were collected from the brain and lungs of the rodents. The activities of AST, ALT, ALKP and GGT in the serum and hepatic glycogen increased in response to infection, while the levels of globulin and total protein increased only in the eighth week of infection and there was a reduction in the levels of serum glucose. Albumin and bilirubin concentrations remained stable during the experiment. Infection with A. cantonensis caused metabolic and histopathological changes in the rodents. This study can contribute to a better understanding of the relationship between A. cantonensis and R. norvegicus.

Protective effect of sildenafil on liver injury induced by intestinal ischemia/reperfusion.

BACKGROUND: This study evaluated the protective effect of sildenafil on liver injury induced by intestinal ischemia-reperfusion. METHODS: Forty female Sprague Dawley rats were divided into 4 groups: sham-control (SC), ischemia (I), ischemia-reperfusion (IR), and ischemia-reperfusion+sildenafil (SIL; sildenafil gavaged at 50mg/kg before operating). A 2-h ischemia-reperfusion was performed by clamping the superior mesenteric artery. Liver function, plasma alanine (ALT) and aspartate (AST) aminotransferase, and intestinal and liver malondialdehyde (MDA) were measured at the end of the experiment. Intestinal and liver tissue damage was examined by histology. Liver samples were immunologically stained for endothelial nitric oxide synthase (eNOS) and proliferating cell nuclear antigen (PCNA). RESULTS: The ALT and AST levels were highest in the IR group and were lower in the SIL group (p<0.05). Intestinal MDA levels were statistically higher in the IR group than in the SC, I and SIL groups. Liver MDA levels were significantly higher in the IR group than in the I and SC groups (p<0.05) and higher than in the SIL group (p>0.05). Intestinal damage based on Chiu scoring was more severe in the IR than in the SIL group (p<0.05). Sildenafil reduced damage and also increased eNOS and PCNA immunoreactivity in liver tissue. CONCLUSIONS: Sildenafil shows a protective effect on intestinal ischemia-reperfusion-induced liver injury, possibly by decreasing vascular resistance through increased nitric oxide levels.

Hepatic gene expression involved in glucose and lipid metabolism in transition cows: effects of fat mobilization during early lactation in relation to milk performance and metabolic changes.

Insufficient feed intake during early lactation results in elevated body fat mobilization to meet energy demands for milk production. Hepatic energy metabolism is involved by increasing endogenous glucose production and hepatic glucose output for milk synthesis and by adaptation of postcalving fuel oxidation. Given that cows differ in their degree of fat mobilization around parturition, indicated by variable total liver fat concentration (LFC), the study investigated the influence of peripartum fat mobilization on hepatic gene expression involved in gluconeogenesis, fatty acid oxidation, ketogenesis, and cholesterol synthesis, as well as transcriptional factors referring to energy metabolism. German Holstein cows were grouped according to mean total LFC on d 1, 14, and 28 after parturition as low [<200mg of total fat/g of dry matter (DM); n=10], medium (200-300 mg of total fat/g of DM; n=10), and high (>300 mg of total fat/g of DM; n=7), indicating fat mobilization during early lactation. Cows were fed total mixed rations ad libitum and held under equal conditions. Liver biopsies were taken at d 56 and 15 before and d 1, 14, 28, and 49 after parturition to measure mRNA abundances of pyruvate carboxylase (PC); phosphoenolpyruvate carboxykinase; glucose-6-phosphatase; propionyl-coenzyme A (CoA) carboxylase α; carnitine palmitoyl-transferase 1A (CPT1A); acyl-CoA synthetase, long chain 1 (ASCL1); acyl-CoA dehydrogenase, very long chain; 3-hydroxy-3-methylglutaryl-CoA synthase 1 and 2; sterol regulatory element-binding factor 1; and peroxisome proliferator-activated factor α. Total LFC postpartum differed greatly among cows, and the mRNA abundance of most enzymes and transcription factors changed with time during the experimental period. Abundance of PC mRNA increased at parturition to a greater extent in high- and medium-LFC groups than in the low-LFC group. Significant LFC × time interactions for ACSL1 and CPT1A during the experimental period indicated variable gene expression depending on LFC after parturition. Correlations between hepatic gene expression and performance data and plasma concentrations of metabolites and hormones showed time-specific relations during the transition period. Elevated body fat mobilization during early lactation affected gene expression involved in gluconeogenesis to a greater extent than gene expression involved in lipid metabolism, indicating the dependence of hepatic glucose metabolism on hepatic lipid status and fat mobilization during early lactation.

Intermittent sustained swimming in 'matrinxã' Brycon amazonicus (Bryconidae: Bryconinae): hematological and metabolic responses

In fish, studies on a wide variety of physiological effects of exercise have been reported since a long time. It has been attributed special attention to some types of exercise, however, its application as a healthful practice in the rearing and welfare of farming fish is rising in last few years. In this particular, long-term intermittent sustained swimming (ISS) has been not yet explored. In this work, the freshwater fish Brycon amazonicus was submitted to (ISS) for 30 days at velocity of 1.0 body-length sec-1 for 12h interspaced by 12h under still water. Hematology and metabolism were evaluated. Exercised fish decreased 30% the erythrocyte number and hemoglobin was unvaried. The stores of liver glycogen and muscular triacylglycerol (TAG) were increased and the metabolic profile was typically aerobic. The slight decrease of liver (TAG) plus the full metabolic and hematic trait allow investing in this kind of exercise a beneficial practice in the rearing of fish species.

Há muito tempo, tem sido relatada uma ampla variedade de efeitos fisiológicos em peixes sob exercício. Tem sido dada especial atenção a alguns tipos de exercício, mas, sua aplicação como prática salutar na criação e para o bem estar dos peixes vem crescendo nos últimos anos. Neste caso, a natação sustentada intermitente (ISS) por longos períodos ainda não foi explorada. Neste trabalho, o peixe de água doce Brycon amazonicus foi submetido a (ISS) por 30 dias à velocidade de 1,0 comprimento corporal s-1 por 12h intervalado de 12h sob regime de água sem movimento. A hematologia e o metabolismo foram avaliados. Os peixes exercitados diminuíram 30% a contagem de eritrócitos e o teor de hemoglobina permaneceu constante. Os estoques de glicogênio hepático, o teor de triacil glycerol muscular (TAG) aumentou e o perfil metabólico foi tipicamente aeróbico. O discreto aumento de TAG hepático, além das características hematológicas e do metabolismo como um todo, instiga-nos investigar este tipo de exercício como uma prática benéfica na criação de peixes.