Butyrylcholinesterase as a marker of inflammation and liver injury in the acute and subclinical phases of canine ehrlichiosis

The aim of this study was to evaluate the role of butyrylcholinesterase (BChE) as a marker of inflammation and liver injury in the acute and subclinical phases of canine ehrlichiosis. Forty-two serum samples of dogs naturally infected with Ehrlichia canis were used, of which 24 were from animals with the acute phase of the disease and 18 with subclinical disease. In addition, sera from 17 healthy dogs were used as negative controls. The hematocrit, BChE activity, hepatic injury (alanine aminotransferase (ALT) and aspartate aminotransferase (AST)), nitric oxide, and cytokines levels were evaluated. The BChE activity was significantly elevated (P < 0.05) in dogs with the acute phase of the disease when compared to healthy animals. However, there was a reduction on BChE activity on dogs with subclinical disease compared to the other two groups. AST and ALT levels were significantly higher (P < 0.05) in the acute phase, as well as the inflammatory mediators (NO_x, TNF-α, INF-γ, IL-4, IL-6) when compared to the control group. On the other hand, IL-10 levels were lower in the acute phase. Based on these results, we are able to conclude that the acute infection caused by E. canis in dogs leads to an increase on seric BChE activity and some inflammatory mediators. Therefore, this enzyme might be used as a marker of acute inflammatory response in dogs naturally infected by this bacterium.     

Reduction in channel catfish hepatic growth hormone receptor expression in response to food deprivation and exogenous cortisol

The objective of this study was to assess the effects of food deprivation and exogenous cortisol administration on somatic growth of channel catfish, Ictalurus punctatus, and examine the resultant changes in circulating insulin-like growth factor-I (IGF-I) concentrations and growth hormone receptor (GHR) gene expression. Integral to this objective, we report the isolation, sequence, and characterization of channel catfish GHR. Sequence analysis and characterization results indicate sequence identity and tissue distribution similar to GHRs in other teleost fish and several functional characteristics conserved in known vertebrate GHRs. The effects of food deprivation and dietary exogenous cortisol administration were assessed as part of a 4-week study. Growth was significantly reduced after 4 weeks in cortisol-fed fish compared to fed-control fish, and fasting resulted in weight loss. At the end of the 4-week study, both IGF-I plasma concentrations and hepatic GHR mRNA abundance were significantly reduced in fasted and cortisol-fed catfish. Levels of hepatic GHR mRNA were positively correlated to circulating IGF-I levels. These results suggest that a reduction in hepatic GHR gene expression might serve as a mechanism for the reduction of circulating IGF-I and growth in channel catfish during periods of food deprivation and stress.     

Plasma levels of cortisol and corticosteroid-binding globulin (CBG) and hepatic CBG mRNA expression in pre- and postnatal pigs

The relationships among hepatic corticosteroid-binding globulin (CBG) mRNA expression and plasma concentrations of cortisol and CBG was evaluated in fetal pigs (n=7-14 per age) on days 50, 70, 80, 90, and 104 of gestation and postnatal pigs (n=8 per age) on days 1, 3, 10, 20, 30, and 40 following birth. In fetal pigs, hepatic CBG mRNA expression was highest (P<0.01) on day 50 as compared to days 90 and 104, exhibiting an overall negative relationship (r=-0.63; P<0.01) with estimated gestation age. Plasma porcine CBG (pCBG) concentration was correlated (r=0.34; P<0.05) with hepatic CBG mRNA level. Plasma cortisol concentrations were not different over this same period. In postnatal pigs, hepatic CBG mRNA expression increased (P<0.01) from days 3 to 40. The pCBG concentration increased (P<0.01) from days 1 (6.1+/-3.4 microg/ml) to 10 (15.1+/-3.7 microg/ml), while plasma cortisol concentration remained constant. An understanding of the relation between hepatic CBG mRNA and circulating pCBG concentrations may provide insight into the mechanisms determining the bioavailability of cortisol necessary in prenatal development and the conservation of cortisol during postnatal development in the pig.     

复合植物精油对脂多糖刺激仔猪肝脏的保护作用

试验旨在研究复合植物精油(OCT)对脂多糖(LPS)刺激仔猪肝脏的保护作用。选取18头仔猪,随机分为对照组、LPS组和OCT+LPS组,每组6个重复。对照组与LPS组饲喂基础日粮,OCT+LPS组在基础日粮中添加50 mg/kg OCT。试验期21 d。于试验第21天,LPS组与OCT+LPS组仔猪腹腔注射LPS,对照组注射等量的生理盐水,3 h后采血,6 h后屠宰。结果表明:与对照组相比,LPS刺激提高了血浆谷丙转氨酶(ALT)、谷草转氨酶(AST)、碱性磷酸酶(ALP)、谷酰转肽酶(GGT)、肝脏诱导型一氧化氮合酶(i-NOS)的活力(P0.05),肝脏热休克蛋白70(HSP70)基因的相对表达量显著提高(P0.05);仔猪肝脏表皮生长因子(EGF)、白细胞介素10(IL-10)、胰岛素样因子(IGF-1)、丝氨酸蛋白激酶(mTOR)基因的相对表达量显著降低(P0.05)。在日粮中添加50 mg/kg的OCT,可缓解LPS导致的仔猪血浆ALT、AST、GGT活力的升高以及肝脏i-NOS活力的升高(P0.05),且有缓解LPS导致的仔猪肝脏MPO活力升高的趋势(P0.1),另外可缓解LPS导致的仔猪肝脏HSP70基因相对表达量的升高以及EGF、IL-10、IGF-1、mTOR等基因相对表达量的降低(P0.05)。综上可知,日粮中添加50 mg/kg的OCT可缓解LPS刺激引起的肝脏炎症反应,提高仔猪肝脏细胞的生长和增殖,进而缓解LPS刺激导致的仔猪肝脏氧化应激损伤。     

Establishment of a time-resolved fluoroimmunoassay for measuring plasma insulin-like growth factor I (IGF-I) in fish: effect of fasting on plasma concentrations and tissue mRNA expression of IGF-I and growth hormone (GH) in channel catfish (Ictalurus punctatus)

A time-resolved fluoroimmunoassay (TR-FIA) was established and validated that allows for the determination of plasma concentrations of insulin-like growth factor I (IGF-I) in three domestically cultured fishes: channel catfish (Ictalurus punctatus), hybrid striped bass (Morone chrysopsxM. saxatilis), and rainbow trout (Oncorhynchus mykiss). Sensitivity of the assay was 0.20 ng/ml. Intra- and inter-assay coefficients of variation (CV) were <7 and <12%, respectively. Serial dilutions of plasma from each species were parallel to the standard curve. Recovery of IGF-I from spiked plasma samples was >90% for all three species of fishes. The IGF-I TR-FIA was biologically validated via its use to determine the effect of fasting on circulating IGF-I levels in channel catfish. Fasting-induced changes in plasma growth hormone (GH), hepatic IGF-I mRNA expression, and pituitary GH mRNA expression were also determined. Fasted channel catfish lost 5.6 and 15.6% body mass after 2 and 4 weeks of fasting, respectively. Plasma IGF-I concentrations were depressed (P<0.05) relative to fed controls following 2 and 4 weeks of fasting. Plasma GH concentrations were not different (P>0.05) in fasted fish after 2 weeks, but significantly increased (P<0.05) by 4 weeks of fasting. Hepatic IGF-I mRNA expression after 2 and 4 weeks of fasting was reduced (P<0.05) relative to fed controls. Pituitary GH mRNA expression was similar (P>0.05) between 2-week-fasted catfish and fed controls, but was increased (P<0.05) in 4-week-fasted catfish. The IGF-I TR-FIA was sensitive, accurate, and precise for all three species of fishes, and provided a low-cost, and non-radioisotopic method for quantifying plasma IGF-I levels in fed and fasted channel catfish.     

土庄绣线菊水浸液对小鼠急性酒精肝损伤保护作用的研究

本试验旨在研究土庄绣线菊水浸液对小鼠急性酒精肝损伤的保护作用。将试验小鼠随机分为低剂量组、中剂量组、高剂量组、模型组和空白组5组。采用一次酒精灌胃法建立急性酒精性肝损伤小鼠模型。建模后,测定各小鼠肝组织谷胱甘肽(GSH)与丙二醛(MDA)含量及血清中冬氨酸氨基转移酶(AST)和丙氨酸转移酶(ALT)的活性,并进行肝组织病理切片观察。结果显示,土庄绣线菊水浸液能够明显降低酒精性肝损伤引起的AST和ALT活性的升高,能有效保持肝脏中GSH含量和明显降低MDA含量,说明土庄绣线菊水浸液对乙醇所致肝损伤具有保护作用,能明显改善酒精引起的肝脏损害。     

Comparison of blood aminotransferase methods for assessment of myopathy and hepatopathy in Florida manatees (Trichechus manatus latirostris)

Muscle injury is common in Florida manatees (Trichechus manatus latirostris). Plasma aspartate aminotransferase (AST) is frequently used to assess muscular damage in capture myopathy and traumatic injury. Therefore, accurate measurement of AST and alanine aminotransferase (ALT) is important in managed, free-ranging animals, as well as in those rehabilitating from injury. Activities of these enzymes, however, are usually not increased in manatees with either acute or chronic muscle damage, despite marked increases in plasma creatine kinase activity. It is hypothesized that this absence of response is due to apoenzymes in the blood not detected by commonly used veterinary assays. Addition of coenzyme pyridoxal-5-phosphate (P5P or vitamin B6) should, therefore, result in higher measured enzyme activities. The objective of this study was to determine the most accurate, precise, and diagnostically useful method for aminotransferase measurement in manatees that can be used in veterinary practices and diagnostic laboratories. Additionally, appropriate collection and storage techniques were assessed. The use of an optimized commercial wet chemical assay with 100 micromol P5P resulted in a positive bias of measured enzyme activities in a healthy population of animals. However, AST and ALT were still much lower than that typically observed in domestic animals and should not be used alone in the assessment of capture myopathy and muscular trauma. Additionally, the dry chemistry analyzer, typically used in clinics, reported significantly higher and less precise AST and ALT activities with poor correlation to those measured with wet chemical methods found in diagnostic laboratories. Therefore, these results cannot be clinically compared. Overall, the optimized wet chemical method was the most precise and diagnostically useful measurement of aminotransferase in samples. Additionally, there was a statistically significant difference between paired serum and plasma measurement, indicating that separate reference intervals should be established for serum and plasma. Finally, storage of these enzymes at -70 degrees C for 1 mo resulted in up to a 25% decrease in enzymatic activity in manatee plasma.     

Biochemical and Histological Study of Rat Liver and Kidney Injury Induced by Cisplatin

Cisplatin is a chemotherapeutic agent widely used in treatment of several cancers. It is documented as a major cause of clinical nephrotoxicity and hepatotoxicity. The purpose of this study was to investigate the involvement of oxidative stress in the pathogenesis of cisplatin-induced liver and kidney injury. Wistar rats were divided into four groups. Group 1 (control) was intraperitoneally (IP) injected with a single dose of 0.85% normal saline. Groups 2, 3 and 4 were IP injected with single doses of cisplatin at 10, 25 and 50 mg/kg body weight (BW), respectively. At 24, 48, 72, 96 and 120 h after injection, BW, levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN), creatinine, malondialdehyde (MDA), and activity of superoxide dismutase (SOD) and histology of the liver and kidney were evaluated. Cisplatin caused a reduction in BW of rats in groups 2, 3 and 4 at all post injection intervals. The levels of serum ALT, AST, BUN and creatinine and MDA of the kidney and liver were markedly increased especially at 48 and 72 h, whereas the activity of SOD was decreased after cisplatin injection. Liver sections revealed moderate to severe congestion with dilation of the hepatic artery, portal vein and bile duct and disorganization of hepatic cords at 50 mg/kg of cisplatin. Kidney sections illustrated mild to moderate tubular necrosis at 25 and 50 mg/kg of cisplatin. Therefore, oxidative stress was implicated in the pathogenesis of liver and kidney injury causing biochemical and histological alterations.     

Changes in leucocyte cytochrome oxidase activity associated with deficiency of copper in laboratory and farm animals.

The cytochrome oxidase activity of circulating leucocytes was investigated by means of a semiquantitative method using blood films. A significant decrease in activity was found in male rats, cattle and sheep that had been deprived of copper. During copper depletion, leucocyte cytochrome oxidase activity declined more slowly than did plasma copper concentration and plasma ferroxidase I activity, and so was less sensitive as a guide to the copper status of the animal.     

Effects of long-term phenobarbital treatment on the liver in dogs

Long-term administration of phenobarbital has been reported to cause hepatic injury in dogs. Phenobarbital induces hepatic enzymes, and it may be difficult to distinguish the effect of enzyme induction on serum liver enzyme activities from actual hepatic damage. The hepatotoxicity of phenobarbital and the impact of enzyme induction on serum liver enzyme activity were investigated prospectively in 12 normal dogs. Phenobarbital was administered for 29 weeks at 5 mg per kilogram of body weight (range, 4.8— 6.6 mg/kg) PO q12h, resulting in therapeutic serum phenobarbital concentrations (20–40 μg/mL). Serum alkaline phosphatase (ALP), alanine transaminase (ALT), aspartate transaminase (AST), γ-glutamyltransferase (GGT), fasted bile acids (fBA), total bilirubin, and albumin were determined before and during treatment. Lateral abdominal radiographs, abdominal ultrasounds, and histopathologic examinations of liver tissue obtained by ultrasound-guided biopsy were performed before and during treatment. Radiographs revealed a moderate increase in liver size in most dogs. Ultrasonographic examination revealed no change in liver echogenicity or architecture. No evidence of morphologic liver damage was observed histopathologically. ALP and ALT increased significantly ( P < .05), GGT increased transiently, and albumin decreased transiently during the study. There were no significant changes in AST, bilirubin, and fBA. These results suggest that increases in serum ALP, ALT, and GGT may reflect enzyme induction rather than hepatic injury during phenobarbital treatment in dogs. Serum AST, fBA, and bilirubin, and ultrasonographic evaluation of the liver are not affected by the enzyme-inducing effect of phenobarbital and can therefore be helpful to assess liver disease in dogs treated with the drug.     

藏药五脉绿绒蒿对小白鼠实验性肝损伤保护作用的研究

为了探讨五脉绿绒蒿对小鼠实验性肝损伤的保护作用,采用一次性腹腔注射四氯化碳花生油(0.12%)方法制作染毒小鼠模型,醋氨酚造成小鼠肝坏死模型;分别给予不同剂量五脉绿绒蒿剂对模型动物进行干预性保护,测定不同实验组小鼠的血液生化指标,并观察醋氨酚中毒对小鼠生存率的影响。结果表明:五脉绿绒蒿剂能降低模型小鼠ALT、AST活性,并能提高醋氨酚中毒的小鼠生存率,对模型小鼠实验性肝损伤具有一定的保护作用。     

Activity and tissue-specific expression of lipases and tumor-necrosis factor alpha in lean and obese cats

Post-heparin plasma activity of lipoprotein lipase (LPL) and hepatic lipase (HL), and fat and muscle activity of LPL were measured in neutered lean and obese cats. Lipoprotein lipase, hormone-sensitive lipase (HSL), and tumor necrosis factor a (TNF) mRNA were measured in muscle and fat tissue with real-time PCR using primers for feline LPL, HSL, and TNF. Lipoprotein lipase plasma and fat activity and fat mRNA levels were significantly lower (50, 80, and 50%, respectively) in obese cats than lean cats, whereas the muscle/fat ratio of LPL was significantly higher in obese compared to lean cats. The activity of HL was not different between the groups. Hormone-sensitive lipase mRNA levels were significantly higher in obese than lean cats. The level of fat TNF also was significantly higher in obese cats than in lean cats, whereas the level in muscle was not different. The lower LPL activity and mRNA expression in fat and the higher LPL and HSL mRNA expression in muscle in obese cats compared to lean cats expectedly favor a redistribution of fatty acids from fat to muscle tissue where they can be deposited or used for energy in times of need. Tumor necrosis factor alpha may regulate this repartitioning process through suppression of adipocyte LPL.     

Lack of glucokinase regulatory protein expression may contribute to low glucokinase activity in feline liver

In most mammals, glucokinase (GK) acts as a hepatic “glucose sensor” that permits hepatic metabolism to respond appropriately to changes in plasma glucose concentrations. GK activity is potently regulated by the glucokinase regulatory protein (GKRP), which is encoded by the GCKR gene. GKRP binds GK in the nucleus and inhibits its activity. GK becomes active when it is released from GKRP and translocates to the cytosol. Low glucokinase (GK) activity is reported to be a principal feature of feline hepatic carbohydrate metabolism but the molecular pathways that regulate GK activity are not known. This study examined the hypothesis that species-specific differences in GKRP expression parallel the low GK activity observed in feline liver. Hepatic GKRP expression was examined using RT-PCR, immunoblot, and confocal immunomicroscopy. The results show that the GCKR gene is present in the feline genome but GCKR mRNA and the GKRP protein were absent in feline liver. The lack of GKRP expression in feline liver indicates that the low GK activity cannot be the result of GKRP-mediated inhibition of the GK enzyme. However, the absence of the permissive effects of GCKR expression on GK expression and activity may contribute to reduced GK enzyme activity in feline liver. The study results show that the cat is a natural model for GCKR knockout and may be useful to study regulation of GCKR expression and its role in hepatic glucose-sensing and carbohydrate metabolism.     

柴芪颗粒抗菌及保肝作用研究

为探讨柴芪颗粒的保肝、体外抗菌作用和对小鼠免疫功能的影响,分别采用四氯化碳(CCl4)和D 氨基半乳糖(D GalN)诱导的小鼠肝损伤模型,给予不同剂量的柴芪颗粒(15、10、5 g/kg体重),测定血清中谷丙转氨酶(ALT)、谷草转氨酶(AST)的活性和肝组织谷胱甘肽(GSH)的含量。研究表明柴芪颗粒对四氯化碳(CCl4 )及D 氨基半乳糖(D GalN)所引起的小鼠肝损害有明显的保护作用,对血清ALT、AST活性升高有明显的降低作用(P<0.01),减少了CCl4 肝损伤小鼠戊巴比妥钠的睡眠时间;并能明显提高小鼠网状内皮系统的吞噬功能,体外试验有一定抑菌作用。可见柴芪颗粒具有抗菌、保肝和提高免疫功能的作用。     

Metabolic adaptations associated with irreversible glucose loss are different to those observed during under-nutrition

In this study the hypothesis that irreversible glucose loss results in an 'uncoupling' of the somatotrophic axis (increasing plasma GH levels and decreasing plasma IGF-I) was tested. During periods of negative energy balance the somatotrophic axis respond by increasing plasma GH and decreasing plasma IGF-I levels. In turn, elevated GH repartitions nutrient by increasing lipolysis and protein synthesis, and decreases protein degradation. Irreversible glucose loss was induced using sub-cutaneous injections of phloridizin. Seven non-lactating cows were treated with 8g/day phloridizin (PHZ) and seven control animals (CTRL, 0g/day), while being restricted to a diet of 80% maintenance. PHZ treatment increased urinary glucose excretion (P<0.001), resulting in hypoglycemia (P<0.001). As a response to this glucose loss, the PHZ treated animals had elevated plasma NEFA (P<0.005) and BHBA (P<0.001) levels. Average plasma insulin concentrations were not altered with PHZ treatment (P=0.059). Plasma GH was not different between the two groups (P>0.1), whereas plasma IGF-I levels decreased significantly (P<0.001) with PHZ treatment. The decline in plasma IGF-I concentrations was mirrored by a decrease in the abundance of hepatic IGF-I mRNA (P=0.005), in addition the abundance of hepatic mRNA for both growth hormone receptors (GHR(tot) and GHR(1A)) was also decreased (P<0.05). Therefore, the irreversible glucose loss resulted in a partial 'uncoupling' of the somatotrophic axis, as no increase in plasma GH levels occurred although plasma IGF-I levels, hepatic IGF-I mRNA declined, and the abundance of liver GH receptor mRNA declined.     

Liver histopathology and liver and serum alanine aminotransferase and alkaline phosphatase activities in epileptic dogs receiving phenobarbital

Phenobarbital (PB) therapy is frequently associated with elevated serum alanine aminotransferase (ALT) and alkaline phosphatase (AP) activities in dogs without clinical signs of liver disease. The goal of this study was to determine if increased serum ALT and AP activities in clinically healthy PB-treated epileptic dogs are due to hepatic enzyme induction or to subclinical liver injury. Liver biopsies were obtained from 12 PB-treated dogs without clinical signs of liver disease but with elevated serum ALT and/or AP activities or both. Liver biopsies were obtained from eight healthy control dogs not receiving PB. Biopsies were evaluated histopathologically (all dogs) and liver homogenates were assayed for ALT (all dogs) and AP (six treated dogs, all controls) activities. As a positive control, liver cytochrome P4502B, an enzyme known to be induced by PB, was measured by benzyloxyresorufin-O-dealkylase activity and immunoblotting (five treated dogs, all controls). Serum AP isoenzyme analyses were performed. Results showed that ALT and AP activities in liver homogenates were not increased in treated dogs compared with controls, whereas the positive control for induction, CYP2B, was dramatically increased in treated dogs. Histopathological examination of liver biopsies revealed more severe and frequent abnormalities in treated dogs compared to controls, but similar types of abnormalities were found in both groups. Serum AP isoenzyme analyses in treated dogs demonstrated increased corticosteroid-induced and liver isoenzyme activities compared to controls. Results do not support induction of ALT or AP in the liver as the cause of elevated serum activities of these enzymes due to PB.     

中药复合剂AFF-Ⅰ口服液对小鼠急性肝损伤血液生化指标的影响

为了研究中药复合剂AFF-Ⅰ口服液对四氯化碳(CCl4)导致小鼠急性肝损伤的保护效果,将60只昆明种小鼠随机分为正常对照、造模、阳性药物对照(联苯双酯)、中药复合剂AFF-Ⅰ口服液高、中、低剂量6组。正常对照组、造模组分别灌服等量的生理盐水,阳性药物对照组按150mg/kg灌胃联苯双酯溶液,中药复合剂AFF-Ⅰ口服液高、中、低剂量组分别按45、30、15mL/kg灌胃,2次/d,连续给药7d。末次给药后1h,正常对照组腹腔注射花生油20mL/kg,其余组腹腔注射10mL/L CCl4花生油溶液20mL/kg,16h后测定血清中天冬氨酸氨基转移酶(AST)、丙氨酸氨基转移酶(ALT)含量和肝组织中超氧化物歧化酶(SOD)、丙二醛(MDA)含量。结果表明,中药复合剂AFF-Ⅰ口服液低、中、高剂量组能显著降低CCl4导致小鼠急性肝损伤血清中AST、ALT含量(P<0.01),显著降低CCl4所致急性肝损伤小鼠肝组织MDA含量,提高肝组织SOD活力(P<0.01)。研究表明,中药复合剂AFF-Ⅰ口服液对小鼠的急性肝损伤具有保护作用。     

Observations on gamma-glutamyl transferase, 5'-nucleotidase and leucine aminopeptidase activities in the plasma of the horse

In 18 horses there was no effect of age or sex on plasma activities of gamma-glutamyl transferase (gamma-GT), 5'-nucleotidase (5'-NT) and leucine aminopeptidase (LAP). All the enzymes were equally stable after storage for one month at -20 degrees C and there was no significant difference between their activities in serum and plasma in clinically normal horses. The pattern of release of gamma-GT, 5'-NT and LAP into plasma was studied in 114 horses which had a variety of orthopaedic, gastrointestinal, cardiovascular and hepatic (necrosis, lipidosis, neoplasia and cirrhosis) conditions. A definitive diagnosis of hepatic disease was established by histological examination of the liver. gamma-GT and 5'-NT were leaked into plasma in hepatic disease and gamma-GT was the more sensitive indicator of liver damage. There was some evidence that gamma-GT and 5'-NT plasma activities may increase in hepatic necrosis as well as in biliary obstruction. LAP was insensitive and not hepatic specific in the horse.