Influence of whole body irradiation on induction of the hepatic microsomal system metabolizing drugs

International Nuclear Information System (INIS)

Szyszko, A.; Bitny-Szlachto, S.

1977-01-01

Effects of whole body irradiation (600 R) on rat liver aminophenazone demethylase activities of the liver homogenate 10,000 X g supernatant and its microsomal fraction were compared. Either activities were found to be decreased by irradiation by some 35%. The phenobarbital treatment (3 x 100 mg/kg i.p.) has turned out to provide higher relative augmentation of the liver demethylase activity in irradiated than in unirradiated rats. The cytoplasmic activity was found to be augmented by phenobarbital treatment 2,21-fold in unirradiated, and 3,20-fold in irradiated rats, and the microsomal activity increased 3,28-fold and 3,77-fold, respectively. Microsomal levels of cytochrome P-450 were found to be not affected by irradiation. (author)

Three conazoles increase hepatic microsomal retinoic acid metabolism and decrease mouse hepatic retinoic acid levels in vivo

International Nuclear Information System (INIS)

Chen, P.-J.; Padgett, William T.; Moore, Tanya; Winnik, Witold; Lambert, Guy R.; Thai, Sheau-Fung; Hester, Susan D.; Nesnow, Stephen

2009-01-01

Conazoles are fungicides used in agriculture and as pharmaceuticals. In a previous toxicogenomic study of triazole-containing conazoles we found gene expression changes consistent with the alteration of the metabolism of all trans-retinoic acid (atRA), a vitamin A metabolite with cancer-preventative properties (Ward et al., Toxicol. Pathol. 2006; 34:863-78). The goals of this study were to examine effects of propiconazole, triadimefon, and myclobutanil, three triazole-containing conazoles, on the microsomal metabolism of atRA, the associated hepatic cytochrome P450 (P450) enzyme(s) involved in atRA metabolism, and their effects on hepatic atRA levels in vivo. The in vitro metabolism of atRA was quantitatively measured in liver microsomes from male CD-1 mice following four daily intraperitoneal injections of propiconazole (210 mg/kg/d), triadimefon (257 mg/kg/d) or myclobutanil (270 mg/kg/d). The formation of both 4-hydroxy-atRA and 4-oxo-atRA were significantly increased by all three conazoles. Propiconazole-induced microsomes possessed slightly greater metabolizing activities compared to myclobutanil-induced microsomes. Both propiconazole and triadimefon treatment induced greater formation of 4-hydroxy-atRA compared to myclobutanil treatment. Chemical and immuno-inhibition metabolism studies suggested that Cyp26a1, Cyp2b, and Cyp3a, but not Cyp1a1 proteins were involved in atRA metabolism. Cyp2b10/20 and Cyp3a11 genes were significantly over-expressed in the livers of both triadimefon- and propiconazole-treated mice while Cyp26a1, Cyp2c65 and Cyp1a2 genes were over-expressed in the livers of either triadimefon- or propiconazole-treated mice, and Cyp2b10/20 and Cyp3a13 genes were over-expressed in the livers of myclobutanil-treated mice. Western blot analyses indicated conazole induced-increases in Cyp2b and Cyp3a proteins. All three conazoles decreased hepatic atRA tissue levels ranging from 45-67%. The possible implications of these changes in hepatic atRA levels

In vitro metabolism of [14C]-toluene by human and rat liver microsomes and liver slices

International Nuclear Information System (INIS)

Chapman, D.E.; Moore, T.J.; Michener, S.R.; Powis, G.

1990-01-01

Toluene metabolites produced by liver microsomes from six human donors included benzylalcohol (Balc), benzaldehyde (Bald) and benzoic acid (Bacid). Microsomes from only one human donor metabolized toluene to p-cresol and o-cresol. Human liver microsomes also metabolized Balc to Bald. Balc metabolism required NADPH, was inhibited by carbon monoxide, and was decreased at a buffer pH of 10. Balc metabolism was not inhibited by ADP-ribose or sodium azide. These results suggest that cytochrome P450 is responsible for the in vitro metabolism of Balc by human liver microsomes. Toluene metabolites formed by human liver slices and released into the incubation media included hippuric acid, and Bacid. Cresols or cresol-conjugates were not detected in liver slice incubation media from any human donor. Toluene metabolism by human liver was compared to metabolism by comparable liver preparations from male Fischer F344 rats. Rates of toluene metabolism by human liver microsomes and liver slices were 9-fold and 1.3-fold greater than for rat liver, respectively. Covalent binding of toluene to human liver microsomes and liver slices was 21-fold and 4-fold greater than for comparable rat liver preparations. Covalent binding of toluene to human microsomes required NADPH, was significantly decreased by coincubation with 4 mM cysteine or 4 mM glutathione, and radioactivity associated with microsomes was decreased by subsequent digestion of microsomes with protease. These results suggest that toluene metabolism and covalent binding of toluene are underestimated if the male Fischer 344 rat is used as a model for human toluene metabolism

High affinity binding of [3H]cocaine to rat liver microsomes

International Nuclear Information System (INIS)

El-Maghrabi, E.A.; Calligaro, D.O.; Eldefrawi, M.E.

1988-01-01

] 3 H]cocaine bound reversible, with high affinity and stereospecificity to rat liver microsomes. Little binding was detected in the lysosomal, mitochondrial and nuclear fractions. The binding kinetics were slow and the kinetically calculated K/sub D/ was 2 nM. Induction of mixed function oxidases by phenobarbital did not produce significant change in [ 3 H]cocaine binding. On the other hand, chronic administration of cocaine reduced [ 3 H]cocaine binding drastically. Neither treatment affected the affinity of the liver binding protein for cocaine. Microsomes from mouse and human livers had less cocaine-binding protein and lower affinity for cocaine than those from rat liver. Binding of [ 3 H]cocaine to rat liver microsomes was insensitive to monovalent cations and > 10 fold less sensitive to biogenic amines than the cocaine receptor in rat striatum. However, the liver protein had higher affinity for cocaine and metabolites except for norcocaine. Amine uptake inhibitors displaced [ 3 H]cocaine binding to liver with a different rank order of potency than their displacement of [ 3 H]cocaine binding to striatum. This high affinity [ 3 H]cocaine binding protein in liver is not likely to be monooxygenase, but may have a role in cocaine-induced hepatotoxicity

In vitro biotransformation of flavonoids by rat liver microsomes

DEFF Research Database (Denmark)

Nielsen, S. E.; Breinholt, V.; Justesen, U.

1998-01-01

1. Sixteen naturally occurring flavonoids were investigated as substrates for cytochrome P450 in uninduced and Aroclor 1254-induced rat liver microsomes. Naringenin, hesperetin, chrysin, apigenin, tangeretin, kaempferol, galangin and tamarixetin were all metabolized extensively by induced rat liver...... pathway leading to the corresponding 3',4'-dihydroxylated flavonoids either by hydroxylation or demethylation. Structural requirements for microsomal hydroxylation appeared to be a single or no hydroxy group on the B-ring of the flavan nucleus. The presence of two or more hydroxy groups on the B......-ring seemed to prevent further hydroxylation. The results indicate that demethylation only occurs in the B-ring when the methoxy group is positioned at C-4'-, and not at the C-3'-position. 3. The CYP1A isozymes were found to be the main enzymes involved in flavonoid hydroxylation, whereas other cytochrome P...

Effects of model traumatic injury on hepatic drug metabolism in the rat. IV. Glucuronidation.

Science.gov (United States)

Griffeth, L K; Rosen, G M; Rauckman, E J

1985-01-01

A previously validated small mammal trauma model, hind-limb ischemia secondary to infrarenal aortic ligation in the rat, was utilized to investigate the effects of traumatic injury on hepatic glucuronidation activity. As was previously observed with hepatic oxidative drug metabolism, model trauma resulted in a significant decrease in the in vivo glucuronidation of chloramphenicol, with a 23% drop in clearance of this drug. The effect on in vivo pharmacokinetics appeared to result from a complex interaction between trauma's differential influences on conjugating enzyme(s), deconjugating enzyme(s), and hepatic UDP-glucuronic acid levels, as well as the relative physiological importance of these variables. Hepatic UDP-glucuronyltransferase activities towards both p-nitrophenol and chloramphenicol were elevated (44-54%) after model injury when measured in native hepatic microsomes. However, microsomes which had been "activated" by treatment with Triton X-100 showed no significant difference between control and traumatized animals. Serum beta-glucuronidase activities were elevated by 58%, while hepatic beta-glucuronidase rose by about 16%. Nevertheless, in vivo deconjugation showed no significant change. Model trauma also resulted in a 46% decrease in hepatic UDP-glucuronic acid content. Thus, the observed post-traumatic depression of in vivo chloramphenicol glucuronidation could be due either to a diminished availability of a necessary cofactor (UDP-glucuronic acid) or to an alteration in enzyme kinetics or function in vivo.

Effects of sh-reagents on rat hepatic aldehyde dehydrogenase activity

Energy Technology Data Exchange (ETDEWEB)

Konoplitskaya, K.L.; Kuz' mina, G.I.; Grigor' yeva, M.V.; Poznyakova, T.N.

The liver serves as the primary organ for the oxidation of ingested ethanol via a pathway involving alcohol- and aldehyde dehydrogenase. In view of the problem of alcoholism, three enzymes are of particular interest in understanding the biochemical mechanism that may be involved in alcohol addiction and in the formulation of therapeutic approaches. While alcohol dehydrogenase has been studied in considerable detail, current attention is centered on aldehyde dehydrogenase. A comparative analysis of the effects of a series of SH-active reagents - tetraethylthiuram disulfide (TETD), 5,5-dithiobisnitrobenzoic acid (DTNB), p-chloromercurybenzoate (PCMB), and N-ethylmaleimide (NEM) - were tested for their effects on the activity of aldehyde dehydrogenase of the hepatic mitochondrial (isozymes I and II) and microsomal (isozyme II) fractions of outbred albino rats. DTNB was found to be inhibited by 100 and 50% mitochondrial isozymes I and II, respectively, and by 20%, the microsomal enzyme under the conditions employed. DTNB and NEM inhibited by 30 and 50% isozymes I and II of the mitochondria, but had no effect on the microsomal isozyme. 24 references, 3 figures.

Glutathione delays varies as-tocopherol oxidation and subsequent lipid peroxidation in rat liver microsomes

International Nuclear Information System (INIS)

Robey, S.; Mavis, R.

1986-01-01

A method has been developed for in vitro trace radiolabeling of rat liver microsomes with 3 H-α-tocopherol (αT*) which allows virtually complete oxidation of the αT* under oxidizing conditions. The supernatant of a 16,000 xg centrifugation of homogenized rat liver, containing the cytosolic rat liver vitamin E (VE) transfer protein, was incubated with an ethanolic solution of αT* for 10 minutes at 37 0 C. Labeled microsomes were collected in the washed 100,000 xg pellet. Microsomes were then incubated with 30 μM Fe 2+ in an NADPH-generating system, and both production of malondialdehyde (MDA) (a product of lipid peroxidation) and oxidation of αT* were monitored over a time course in the presence and absence of glutathione (GSH). The results indicate virtually complete oxidation of αT* precedes significant membrane lipid peroxidation, and that addition of 5 mM GSH delays both αT* oxidation and subsequent MDA production. This suggests that the previously observed VE-dependent heat labile inhibition of microsomal lipid peroxidation by GSH involves maintaining membrane levels of α-tocopherol

A human cytochrome P-450 is recognized by anti-liver/kidney microsome antibodies in autoimmune chronic hepatitis.

Science.gov (United States)

Kiffel, L; Loeper, J; Homberg, J C; Leroux, J P

1989-02-28

1- Anti-liver/kidney microsome autoantibodies type 1 (anti-LKM1), observed in some children with chronic active hepatitis, were used to isolate their antigen in human liver microsomes. A protein, called P-LKM1 was thus purified. This protein was recognized by a rabbit antiserum directed against the related human cytochromes P-450 bufI and P-450 bufII. 2- A human liver microsomal protein immunoprecipitated with anti-LKM1 sera was also recognized by anti cytochromes P-450 bufI/II antibodies. 3- Anti-LKM1 antibodies potently inhibited microsomal bufuralol 1'-hydroxylation. These results displayed the possible identity between cytochrome P-450 bufI/II and LKM1 antigen.

Antioxidant Capacity of Flavonoids in Hepatic Microsomes Is not Reflected by Antioxidant Effects In Vivo

Directory of Open Access Journals (Sweden)

Garry Duthie

2012-01-01

Full Text Available Flavonoids are polyphenolic compounds with potential antioxidant activity via multiple reduction capacities. Oxidation of cellular lipids has been implicated in many diseases. Consequently, this study has assessed the ability of several dietary flavonoid aglycones to suppress lipid peroxidation of hepatic microsomes derived from rats deficient in the major lipid soluble antioxidant, dα-tocopherol. Antioxidant effectiveness was galangin > quercetin > kaempferol > fisetin > myricetin > morin > catechin > apigenin. However, none of the flavonoids were as effective as dα-tocopherol, particularly at the lowest concentrations used. In addition, there appears to be an important distinction between the in vitro antioxidant effectiveness of flavonoids and their ability to suppress indices of oxidation in vivo. Compared with dα-tocopherol, repletion of vitamin E deficient rats with quercetin, kaempferol, or myricetin did not significantly affect indices of lipid peroxidation and tissue damage. Direct antioxidant effect of flavonoids in vivo was not apparent probably due to low bioavailability although indirect redox effects through stimulation of the antioxidant response element cannot be excluded.

Regulation of hepatic level of fatty-acid-binding protein by hormones and clofibric acid in the rat.

Science.gov (United States)

Nakagawa, S; Kawashima, Y; Hirose, A; Kozuka, H

1994-01-01

Regulation of the hepatic level of fatty-acid-binding protein (FABP) by hormones and p-chlorophenoxyisobutyric acid (clofibric acid) was studied. The hepatic level of FABP, measured as the oleic acid-binding capacity of the cytosolic FABP fraction, was decreased in streptozotocin-diabetic rats. The level of FABP was markedly increased in adrenalectomized rats, and the elevation was prevented by the administration of dexamethasone. Hypothyroidism decreased the level of FABP and hyperthyroidism increased it. A high correlation between the incorporation of [14C]oleic acid in vivo into hepatic triacylglycerol and the level of FABP was found for normal, diabetic and adrenalectomized rats. The level of FABP was increased by administration of clofibric acid to rats in any altered hormonal states, as was microsomal 1-acylglycerophosphocholine (1-acyl-GPC) acyltransferase, a peroxisome-proliferator-responsive parameter. These results suggest that the hepatic level of FABP is under regulation by multiple hormones and that clofibric acid induces FABP and 1-acyl-GPC acyltransferase by a mechanism which may be distinct from that by which hormones regulate the level of FABP. PMID:8110197

Dietary saturated and monounsaturated fats protect against acute acetaminophen hepatotoxicity by altering fatty acid composition of liver microsomal membrane in rats

Directory of Open Access Journals (Sweden)

Shim Eugene

2011-10-01

Full Text Available Abstract Background Dietary polyunsaturated fats increase liver injury in response to ethanol feeding. We evaluated the effect of dietary corn oil (CO, olive oil (OO, and beef tallow (BT on fatty acid composition of liver microsomal membrane and acute acetaminophen hepatotoxicity. Methods Male Sprague-Dawley rats were fed 15% (wt/wt CO, OO or BT for 6 weeks. After treatment with acetaminophen (600 mg/kg, samples of plasma and liver were taken for analyses of the fatty acid composition and toxicity. Results Treatment with acetaminophen significantly elevated levels of plasma GOT and GPT as well as hepatic TBARS but reduced hepatic GSH levels in CO compared to OO and BT groups. Acetaminophen significantly induced protein expression of cytochrome P450 2E1 in the CO group. In comparison with the CO diet, lower levels of linoleic acid, higher levels of oleic acids and therefore much lower ratios of linoleic to oleic acid were detected in rats fed OO and BT diets. Conclusions Dietary OO and BT produces similar liver microsomal fatty acid composition and may account for less severe liver injury after acetaminophen treatment compared to animals fed diets with CO rich in linoleic acid. These findings imply that types of dietary fat may be important in the nutritional management of drug-induced hepatotoxicity.

Comparative Metabolism Study of Five Protoberberine Alkaloids in Liver Microsomes from Rat, Rhesus Monkey, and Human.

Science.gov (United States)

Li, Yan; Zhou, Yanyan; Si, Nan; Han, Lingyu; Ren, Wei; Xin, Shaokun; Wang, Hongjie; Zuo, Ran; Wei, Xiaolu; Yang, Jian; Zhao, Haiyu; Bian, Baolin

2017-11-01

Protoberberine alkaloids including berberine, palmatine, jatrorrhizine, coptisine, and epiberberine are major components in many medicinal plants. They have been widely used for the treatment of cancer, inflammation, diabetes, depression, hypertension, and various infectious areas. However, the metabolism of five protoberberine alkaloids among different species has not been clarified previously. In order to elaborate on the in vitro metabolism of them, a comparative analysis of their metabolic profile in rat, rhesus monkey, and human liver microsomes was carried out using ultrahigh-performance liquid chromatography coupled with a high-resolution linear trap quadrupole-Orbitrap mass spectrometer (UHPLC-electrospray ionization-Orbitrap MS) for the first time. Each metabolite was identified and semiquantified by its accurate mass data and peak area. Fifteen metabolites were characterized based on accurate MS/MS spectra and the proposed MS/MS fragmentation pathways including demethylation, hydroxylation, and methyl reduction. Among them, the content of berberine metabolites in human liver microsomes was similar with those in rhesus monkey liver microsomes, whereas berberine in rat liver microsomes showed no demethylation metabolites and the content of metabolites showed significant differences with that in human liver microsomes. On the contrary, the metabolism of palmatine in rat liver microsomes resembled that in human liver microsomes. The content of jatrorrhizine metabolites presented obvious differences in all species. The HR-ESI-MS/MS fragmentation behavior of protoberberine alkaloids and their metabolic profile in rat, rhesus monkey, and human liver microsomes were investigated for the first time. The results demonstrated that the biotransformation characteristics of protoberberine alkaloids among different species had similarities as well differences that would be beneficial for us to better understand the pharmacological activities of protoberberine alkaloids

Photoaffinity labeling of steroid 5 alpha-reductase of rat liver and prostate microsomes

International Nuclear Information System (INIS)

Liang, T.; Cheung, A.H.; Reynolds, G.F.; Rasmusson, G.H.

1985-01-01

21-Diazo-4-methyl-4-aza-5 alpha-pregnane-3,20-dione (Diazo-MAPD) inhibits steroid 5 alpha-reductase in liver microsomes of female rats with a K/sub i/ value of 8.7 +/- 1.7 nM, and the inhibition is competitive with testosterone. It also inhibits the binding of a 5 alpha-reductase inhibitor, [ 3 H] 17 beta-N,N-diethylcarbamoyl-4-methyl-4-aza-5 alpha-androstan-3-one ([ 3 H]4-MA), to the enzyme in liver microsomes. The inhibition of 5 alpha-reductase activity and of inhibitor binding activity by diazo-MAPD becomes irreversible upon UV irradiation. [1,2- 3 H]Diazo-MAPD binds to a single high affinity site in liver microsomes of female rats, and this binding requires NADPH. Without UV irradiation, this binding is reversible, and it becomes irreversible upon UV irradiation. Both the initial reversible binding and the subsequent irreversible conjugation after UV irradiation are inhibited by inhibitors (diazo-MAPD and 4-MA) and substrates (progesterone and testosterone) of 5 alpha-reductase, but they are not inhibited by 5 alpha-reduced steroids. Photoaffinity labeled liver microsomes of female rats were solubilized and fractionated by high performance gel filtration. The radioactive conjugate eluted in one major peak at Mr 50,000

Dietary sea cucumber cerebroside alleviates orotic acid-induced excess hepatic adipopexis in rats

Science.gov (United States)

2012-01-01

Background Nonalcoholic fatty liver disease (NAFLD) is a prevalent chronic liver disease in industrialized countries. The present study was undertaken to explore the preventive effect of dietary sea cucumber cerebroside (SCC) extracted from Acaudina molpadioides in fatty liver rats. Methods Male Wistar rats were randomly divided into four groups including normal control group, NAFLD model group, and two SCC-treated groups with SCC at 0.006% and 0.03% respectively. The fatty liver model was established by administration of 1% orotic acid (OA) to the rats. After 10d, serum and hepatic lipid levels were detected. And the serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities were also determined. Besides, to gain the potential mechanism, the changes of key enzymes and gene expressions related to the hepatic lipid metabolism were measured. Results Dietary SCC at the level of 0.006% and 0.03% ameliorated the hepatic lipid accumulation in fatty liver rats. SCC administration elevated the serum triglyceride (TG) level and the ALT, AST activities in OA-fed rats. The activities of hepatic lipogenic enzymes including fatty acid synthase (FAS), malic enzyme (ME) and glucose-6-phosphatedehydrogenase (G6PDH) were inhibited by SCC treatment. And the gene expressions of FAS, ME, G6PDH and sterol-regulatory element binding protein (SREBP-1c) were also reduced in rats fed SCC. However, dietary SCC didn't affect the activity and mRNA expression of carnitine palmitoyltransferase (CPT) in liver. Besides, suppression of microsomal triglyceride transfer protein (MTP) activity was observed in SCC-feeding rats. Conclusions These results suggested that dietary SCC could attenuate hepatic steatosis due to its inhibition of hepatic lipogenic gene expression and enzyme activity and the enhancement of TG secretion from liver. PMID:22569330

Dietary sea cucumber cerebroside alleviates orotic acid-induced excess hepatic adipopexis in rats

Directory of Open Access Journals (Sweden)

Zhang Bei

2012-05-01

Full Text Available Abstract Background Nonalcoholic fatty liver disease (NAFLD is a prevalent chronic liver disease in industrialized countries. The present study was undertaken to explore the preventive effect of dietary sea cucumber cerebroside (SCC extracted from Acaudina molpadioides in fatty liver rats. Methods Male Wistar rats were randomly divided into four groups including normal control group, NAFLD model group, and two SCC-treated groups with SCC at 0.006% and 0.03% respectively. The fatty liver model was established by administration of 1% orotic acid (OA to the rats. After 10d, serum and hepatic lipid levels were detected. And the serum alanine aminotransferase (ALT and aspartate aminotransferase (AST activities were also determined. Besides, to gain the potential mechanism, the changes of key enzymes and gene expressions related to the hepatic lipid metabolism were measured. Results Dietary SCC at the level of 0.006% and 0.03% ameliorated the hepatic lipid accumulation in fatty liver rats. SCC administration elevated the serum triglyceride (TG level and the ALT, AST activities in OA-fed rats. The activities of hepatic lipogenic enzymes including fatty acid synthase (FAS, malic enzyme (ME and glucose-6-phosphatedehydrogenase (G6PDH were inhibited by SCC treatment. And the gene expressions of FAS, ME, G6PDH and sterol-regulatory element binding protein (SREBP-1c were also reduced in rats fed SCC. However, dietary SCC didn't affect the activity and mRNA expression of carnitine palmitoyltransferase (CPT in liver. Besides, suppression of microsomal triglyceride transfer protein (MTP activity was observed in SCC-feeding rats. Conclusions These results suggested that dietary SCC could attenuate hepatic steatosis due to its inhibition of hepatic lipogenic gene expression and enzyme activity and the enhancement of TG secretion from liver.

Opuntia ficus indica (nopal) attenuates hepatic steatosis and oxidative stress in obese Zucker (fa/fa) rats.

Science.gov (United States)

Morán-Ramos, Sofía; Avila-Nava, Azalia; Tovar, Armando R; Pedraza-Chaverri, José; López-Romero, Patricia; Torres, Nimbe

2012-11-01

Nonalcoholic fatty liver disease (NAFLD) is associated with multiple factors such as obesity, insulin resistance, and oxidative stress. Nopal, a cactus plant widely consumed in the Mexican diet, is considered a functional food because of its antioxidant activity and ability to improve biomarkers of metabolic syndrome. The aim of this study was to assess the effect of nopal consumption on the development of hepatic steatosis and hepatic oxidative stress and on the regulation of genes involved in hepatic lipid metabolism. Obese Zucker (fa/fa) rats were fed a control diet or a diet containing 4% nopal for 7 wk. Rats fed the nopal-containing diet had ∼50% lower hepatic TG than the control group as well as a reduction in hepatomegaly and biomarkers of hepatocyte injury such as alanine and aspartate aminotransferases. Attenuation of hepatic steatosis by nopal consumption was accompanied by a higher serum concentration of adiponectin and a greater abundance of mRNA for genes involved in lipid oxidation and lipid export and production of carnitine palmitoyltransferase-1 and microsomal TG transfer proteins in liver. Hepatic reactive oxygen species and lipid peroxidation biomarkers were significantly lower in rats fed nopal compared with the control rats. Furthermore, rats fed the nopal diet had a lower postprandial serum insulin concentration and a greater liver phosphorylated protein kinase B (pAKT):AKT ratio in the postprandial state. This study suggests that nopal consumption attenuates hepatic steatosis by increasing fatty acid oxidation and VLDL synthesis, decreasing oxidative stress, and improving liver insulin signaling in obese Zucker (fa/fa) rats.

Inhibition of rat microsomal lipid peroxidation by the oral administration of D002

Directory of Open Access Journals (Sweden)

Menéndez R.

2000-01-01

Full Text Available The effect of D002, a defined mixture of higher primary alcohols purified from bee wax, on in vivo and in vitro lipid peroxidation was studied. The extent of lipid peroxidation was measured on the basis of the levels of thiobarbituric acid reactive substances (TBARS. When D002 (5-100 mg/kg body weight was administered orally to rats for two weeks, a partial inhibition of the in vitro enzymatic and non-enzymatic lipid peroxidation was observed in liver and brain microsomes. Maximal protection (46% occurred at a dose of 25 mg/kg. D002 behaved differently depending on both the presence of NADPH and the integrity of liver microsomes, which suggests that under conditions where microsomal metabolism was favored the protective effect of D002 was increased. D002 (25 mg/kg also completely inhibited carbon tetrachloride- and toluene-induced in vivo lipid peroxidation in liver and brain. Also, D002 significantly lowered in a dose-dependent manner the basal level of TBARS in liver (19-40% and brain (28-44% microsomes. We conclude that the oral administration of D002 (5, 25 and 100 mg/kg for two weeks protected rat liver and brain microsomes against microsomal lipid peroxidation in vitro and in vivo. Thus, D002 could be useful as a dietary natural antioxidant supplement. More studies are required before these data can be extrapolated to the recommendation for the use of D002 as a dietary antioxidant supplement for humans.

Incubation of 14C-trichloroethylene vapor with rat liver microsomes: uptake of radioactivity and covalent protein binding of metabolites

International Nuclear Information System (INIS)

Bolt, H.M.; Wolowski, L.; Buchter, A.; Bolt, W.; Gil, D.L.

1977-01-01

Microsomal uptake irreversible protein binding of labelled trichloroehtylene was measured following incubation with rat liver microsomes in an all-glass vacuum system. If the cofactor for oxidative metabolism, NADPH, is not added, the gaseous trichloroethylene rapidly equilibrates with the microsomal suspension. Addition of NADPH results in a further uptake of 14 C-trichloroethylene from the gas phase, linearly with time, which is due to enzymic metabolism. This part of uptake is inhibited by some arylimidazoles and 1.2.3-benzothiadiazoles. The compounds of greatest inhibitory potency were 6-chloro-1.2.3-benzothiadiazole and 5.6-dimethyl-1.2.3-benzothiadiazole. Part of the metabolites of 14 C-trichloroethylene formed by rat liver microsomes were irreversibly bound to microsomal protein, amounting up to 1 nmol per mg microsomal protein per hour. Model experiments on uptake of 14 C-trichloroethylene from the gas phase by albumin solutions and liposomal suspensions (from lecithin) showed a rapid equilibration of trichloroethylene also with these systems. Comparison with previous analogous data on vinyl chloride revealed an about 10 times higher affinity of trichloroethylene to albumin and lipid, consistent with the behaviour of both compounds in the rat liver microsomal system. (orig.) [de

Oxidation of esterified arachidonate by rat liver microsomes

International Nuclear Information System (INIS)

Davis, H.W.; Suzuki, T.; Schenkman, J.B.

1986-01-01

The authors have previously demonstrated a relationship between phospholipid arachidonate in liver microsomes and malondialdehyde (MDA) formation during lipid peroxidation. In this study arachidonic acid (U- 14 C) was incorporated into rat liver microsomes and NADPH-supported peroxidation was carried out at 37 0 C for 15 minutes. The microsomes were pelleted by centrifugation and the labeled products in the supernatant were isolated by a solid phase method. Pellets were hydrolyzed with phospholipase A 2 and extracted with diethyl ether and the products from both fractions were separated by reverse phase HPLC. The results show that (1) oxidation occurs in all of the major phospholipids but that phosphatidylethanolamine is the most susceptible; (2) a linear correlation exists between MDA formation and supernatant radioactivity; (3) several different polar products are found in both the supernatant and the hydrolyzed pellet but that the ratios of product peaks in HPLC do not change during the peroxidation, indicating no secondary metabolism or propagation; and (4) cytochrome P-450 is not involved in the peroxidative reactions since no oxidation occurs in the absence of Fe 3+ and since product formation is unaffected in the presence of carbon monoxide

Lichen planus, liver kidney microsomal (LKM1) antibodies and hepatitis C virus antibodies.

Science.gov (United States)

Divano, M C; Parodi, A; Rebora, A

1992-01-01

No anti-liver kidney microsomal (LKM1) antibodies were detected in 46 patients with LP, 16 of whom had also a chronic liver disease (CLD). In contrast, anti-hepatitis C virus (HCV) antibodies were found in 10% of patients with LP and in 50% of those with LP and CLD. Anti-HCV antibodies may be considered as a false-positive reaction in 56% of cases, especially when anti-LKM1 antibodies are present. Our findings do not support such a hypothesis, but suggest that CLD in LP patients is, at least in Italy, mostly a postviral chronic active hepatitis.

Hepatitis C virus infection associated with liver-kidney microsomal antibody type 1 (LKM1) autoantibodies in children.

Science.gov (United States)

Bortolotti, Flavia; Muratori, Luigi; Jara, Paloma; Hierro, Loreto; Verucchi, Gabriella; Giacchino, Raffaella; Barbera, Cristiana; Zancan, Lucia; Guido, Maria; Resti, Massimo; Pedditzi, Sabrina; Bianchi, Francesco; Gatta, Angelo

2003-02-01

To evaluate the clinical pattern and evolution of chronic hepatitis C in children with liver/kidney microsomal antibody type 1 autoantibodies (LKM1). A multicenter, retrospective study, including the following groups of children with hepatitis C virus infection: (1). 21 consecutive LKM1-positive patients, (2). 42 age- and sex- matched LKM1-negative patients, and (3). 4 interferon-induced LKM1-positive cases. LKM1 reactivity to human microsomes and recombinant cytochrome P450IID6 (CYP2D6) was assayed by immunoblotting. Clinical and biochemical features overlapped in LKM1-positive and LKM1-negative children, but a fibrosis score >3 (range 0-6) was significantly more frequent (P =.04) in the former. Reactivity to microsomal protein and CYP2D6 was significantly (P =.02) associated with LKM1 titers >or=1:320 and was found in 39% of patients, including severe cases and both children (of 4 treated) who achieved a sustained alanine aminotransferase (ALT) normalization after steroid treatment. Five of 7 LKM1-positive children treated with interferon had an ALT exacerbation. LKM1-positive hepatitis C in children is characterized by a wide spectrum of biochemical, serologic, and histologic features. Whether autoimmunity may contribute to liver damage in a subgroup of patients with more severe liver disease, high LKM1 titers, and reactivity to CYP2D6 is a question deserving further investigation.

Grapefruit juice intake does not enhance but rather protects against aflatoxin B1-induced liver DNA damage through a reduction in hepatic CYP3A activity.

Science.gov (United States)

Miyata, Masaaki; Takano, Hiroki; Guo, Lian Q; Nagata, Kiyoshi; Yamazoe, Yasushi

2004-02-01

Influence of grapefruit juice intake on aflatoxin B1 (AFB1)-induced liver DNA damage was examined using a Comet assay in F344 rats given 5 mg/kg AFB1 by gavage. Rats allowed free access to grapefruit juice for 5 days prior to AFB1 administration resulted in clearly reduced DNA damage in liver, to 65% of the level in rats that did not receive grapefruit juice. Furthermore, rats treated with grapefruit juice extract (100 mg/kg per os) for 5 days prior to AFB1 treatment also reduced the DNA damage to 74% of the level in rats that did not receive grapefruit juice. No significant differences in the portal blood and liver concentrations of AFB1 were observed between grapefruit juice intake rats and the controls. In an Ames assay with AFB1 using Salmonella typhimurium TA98, lower numbers of revertant colonies were detected with hepatic microsomes prepared from rats administered grapefruit juice, compared with those from control rats. Microsomal testosterone 6beta-hydroxylation was also lower with rats given grapefruit juice than with control rats. Immunoblot analyses showed a significant decrease in hepatic CYP3A content, but not CYP1A and CYP2C content, in microsomes of grapefruit juice-treated rats than in non-treated rats. No significant difference in hepatic glutathione S-transferase (GST) activity and glutathione content was observed in the two groups. GSTA5 protein was not detected in hepatic cytosol of the two groups. In microsomal systems, grapefruit juice extract inhibited AFB1-induced mutagenesis in the presence of a microsomal activation system from livers of humans as well as rats. These results suggest that grapefruit juice intake suppresses AFB1-induced liver DNA damage through inactivation of the metabolic activation potency for AFB1 in rat liver.

Major antigen of liver kidney microsomal autoantibodies in idiopathic autoimmune hepatitis is cytochrome P450db1.

OpenAIRE

Manns, M P; Johnson, E F; Griffin, K J; Tan, E M; Sullivan, K F

1989-01-01

Type 1, liver kidney microsomal autoantibodies (LKM-1) are associated with a subgroup of idiopathic autoimmune type, chronic active hepatitis (CAH). The antigenic specificity of LKM-1 autoantibodies from 13 patients was investigated by immunoblot analysis of human liver microsomal proteins. Polypeptides of 50, 55, and 64 kD were detected with these antisera. A high titer LKM-1 serum was selected to screen a human liver lambda gt11 cDNA expression library, resulting in the isolation of several...

Effects of tin-protoporphyrin administration on hepatic xenobiotic metabolizing enzymes in the juvenile rat

International Nuclear Information System (INIS)

Stout, D.L.; Becker, F.F.

1988-01-01

The heme analogue tin-protoporphyrin IX (SnP) is a potent inhibitor of microsomal heme oxygenase. Administration of SnP to neonatal rats can prevent hyperbilirubinemia by blocking the postnatal increase of heme oxygenase activity. Apparently innocuous at therapeutic doses, it is of potential clinical value for chemoprevention of neonatal jaundice. We found that when 50-g male Sprague-Dawley rats were treated daily with 50 mumol of SnP/kg sc for 6 days, hepatic microsomal cytochromes b5 and P-450 were significantly diminished. Cytochrome P-450 reductase, two P-450-dependent monooxygenases, aminopyrine demethylase and benzo(a)pyrene hydroxylase, and catalase, a peroxisomal hemoprotein, were also significantly diminished. These results suggested that SnP might significantly affect the metabolism of other xenobiotics. This possibility was confirmed by the finding that hexobarbital-induced sleep lasted 4 times longer in SnP-treated rats than in controls. Inhibition of protein synthesis by SnP was ruled out as the cause of hemoprotein loss when administration of [ 3 H]leucine to SnP-treated and control rats demonstrated that proteins of the microsomal, cytosolic, and plasma membrane fractions of the livers from both groups incorporated similar levels of leucine. When 55 FeCl 3 and [2- 14 C]glycine were administered to measure heme synthesis, heme extract from the livers of SnP-treated rats contained 4 times more label from iron and glycine than did heme from control livers. Despite the apparent increased rate of heme synthesis in SnP-treated rats, each of the three cell fractions demonstrated a significant loss of heme but contained sizable amounts of SnP. These findings suggest that SnP causes a decrease of functional hemoprotein and partial loss of enzymic activity by displacing intracellular heme

DDT increases hepatic testosterone metabolism in rats

Energy Technology Data Exchange (ETDEWEB)

Sierra-Santoyo, Adolfo; Albores, Arnulfo; Cebrian, Mariano E. [Cinvestav-IPN, Seccion de Toxicologia, Mexico (Mexico); Hernandez, Manuel [Cinvestav-IPN, Departamento de Biologia Celular (Mexico)

2005-01-01

DDT and its metabolites are considered as endocrine disruptors able to promote hormone-dependent pathologies. We studied the effects of technical-grade DDT on hepatic testosterone metabolism and testosterone hydroxylase activity ratios in the rat. Male and female Wistar rats were treated by gavage with a single dose of technical-grade DDT (0, 0.1, 1, 10, and 100 mg/kg body weight) and killed 24 h later. Hepatic microsomes were incubated with [4-{sup 14}C]-testosterone and the metabolites were separated by thin-layer chromatography and quantified by radio scanning. DDT increased testosterone biotransformation and modified the profile of metabolites produced in a sex-dependent manner. Males treated with a representative dose (10 mg/kg) produced relatively less androstenedione (AD), 2{alpha}-hydroxytestosterone (OHT), and 16{alpha}-OHT but higher 6{beta}-OHT whereas treated females produced less 7{alpha}-OHT and AD but higher 6{beta}-OHT and 6{alpha}-OHT than their respective controls. In both sexes DDT decreased the relative proportion of AD and increased that of 6{beta}-OHT suggesting that the androgen-saving pathway was affected. The testosterone 6{alpha}-/15{alpha}-OHT ratio, a proposed indicator of demasculinization, was increased in treated males. This effect was in agreement with the demasculinizing ability proposed for DDT. The effects on 6{alpha}-/16{alpha}-OHT and 6-dehydrotestosterone/16{alpha}-OHT ratios followed a similar tendency, with the ratio 6{alpha}-/16{alpha}-OHT being the most sensitive marker. Interestingly, these ratios were reduced in treated females suggesting that technical-grade DDT shifted testosterone hydroxylations toward a more masculine pattern. Thus, technical-grade DDT altered the hepatic sexual dimorphism in testosterone metabolism and decreased the metabolic differences between male and female rats. (orig.)

Inhibition of rat mammary microsomal oxidation of ethanol to acetaldehyde by plant polyphenols.

Science.gov (United States)

Maciel, María Eugenia; Castro, José Alberto; Castro, Gerardo Daniel

2011-07-01

We previously reported that the microsomal fraction from rat mammary tissue is able to oxidize ethanol to acetaldehyde, a mutagenic-carcinogenic metabolite, depending on the presence of NADPH and oxygen but not inhibited by carbon monoxide or other cytochrome P450 inhibitors. The process was strongly inhibited by diphenyleneiodonium, a known inhibitor of NADPH oxidase, and by nordihydroguaiaretic acid, an inhibitor of lipoxygenases. This led us to suggest that both enzymes could be involved. With the purpose of identifying natural compounds present in food with the ability to decrease the production of acetaldehyde in mammary tissue, in the present studies, several plant polyphenols having inhibitory effects on lipoxygenases and of antioxidant nature were tested as potential inhibitors of the rat mammary tissue microsomal pathway of ethanol oxidation. We included in the present screening study 32 polyphenols having ready availability and that were also tested against the rat mammary tissue cytosolic metabolism of ethanol to acetaldehyde. Several polyphenols were also able to inhibit the microsomal ethanol oxidation at concentrations as low was 10-50 μM. The results of these screening experiments suggest the potential of several plant polyphenols to prevent in vivo production and accumulation of acetaldehyde in mammary tissue.

Inhibition of rat liver microsomal lipid peroxidation by N-acyldehydroalanines: An in vitro comparative study

Energy Technology Data Exchange (ETDEWEB)

Buc-Calderon, P.; Roberfroid, M. (Universite Catholique de Louvain, Brussels (Belgium))

1989-09-01

Captodative substituted olefins are radical scavengers which react with free radicals to form stabilized radical adducts. One of those compounds, N-(paramethoxyphenylacetyl)dehydroalanine (AD-5), may react and scavenge both superoxide anion (O-2) and alk-oxyl radicals (RO.), and in this way prevent the appearance of their mediated biological effects. Nitrofurantoin and tert-butyl hydroperoxide were used as model compounds to stimulate free radical production and their mediated lipid peroxidation in rat liver microsomes. In addition, lipid peroxidation was also initiated by exposure of rat liver microsomal suspensions to ionizing radiation (gamma rays). The microsomal lipid peroxidation induced by these chemicals and physical agents was inhibited by the addition of AD-5. These effects were dose-dependent in a millimolar range of concentration. In addition, AD-5 has no effect on microsomal electron transport, showing that NADPH-cytochrome P450 reductase activity was not modified. These data, together with the comparisons of the effects of AD-5 and some antioxidant molecules such as superoxide dismutase, uric acid, and mannitol, support the conclusion that inhibition of lipid peroxidation by AD-5 is the result of its free radical scavenger activity. In addition, the inhibitory effect of AD-5 on microsomal lipid peroxidation was dependent of the nature of the free radical species involved in the initiation of the process, suggesting that O-2 is scavenged more efficiently than RO.

[The effect of alpha-tocopherol and ionol on the physical structure of the membranes of rat liver microsomes under conditions of antioxidant insufficiency].

Science.gov (United States)

Gubskiĭ, Iu I; Boldeskul, A E; Primak, R G; Zadorina, O V

1989-01-01

Physiochemical conformity of the alpha-tocopherol interaction with hepatic microsomal membranes has been studied by means of fluorescent probes (pyrene and 1-anilinonaphthalene-8-sulphonate). The microsomal membrane microviscosity is shown to sharply decrease under conditions of the antioxidant deficiency with vitamin E expelled into animals normalizes microviscosity, but feebly influences the microsomal surface charge. Microcalorimetry has been used to establish that penetration of tocopherol into microsomal membranes was accompanied by the exothermic effect.

Identification of a tryptanthrin metabolite in rat liver microsomes by liquid chromatography/electrospray ionization-tandem mass spectrometry.

Science.gov (United States)

Lee, Sang Kyu; Kim, Ghee Hwan; Kim, Dong Hyeon; Kim, Dong Hyun; Jahng, Yurngdong; Jeong, Tae Cheon

2007-10-01

Tryptanthrin originally isolated from Isatis tinctoria L. has been characterized to have anti-inflammatory activities through the dual inhibition of cyclooxygenase-2 and 5-lipoxygenase mediated prostaglandin and leukotriene syntheses. To characterize phase I metabolite(s), tryptanthrin was incubated with rat liver microsomes in the presence of NADPH-generating system. One metabolite was identified by liquid chromatography/electrospray ionization-tandem mass spectrometry. M1 could be identified as a metabolite mono-hydroxylated on the aromatic ring of indole moiety from the MS(2) spectra of protonated tryptanthrin and M1. The structure of metabolite was confirmed as 8-hydroxytryptanthrin with a chemically synthesized authentic standard. The formation of M1 was NADPH-dependent and was inhibited by SKF-525A, a general CYP-inhibitor, indicating the cytochrome P450 (CYP)-mediated reaction. In addition, it was proposed that M1 might be formed by CYP 1A in rat liver microsomes from the experiments with enriched rat liver microsomes.

Metabolism of UV-filter benzophenone-3 by rat and human liver microsomes and its effect on endocrine-disrupting activity

Energy Technology Data Exchange (ETDEWEB)

Watanabe, Yoko, E-mail: y-watanabe@nichiyaku.ac.jp [Graduate School of Biomedical and Health Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8553 (Japan); Nihon Pharmaceutical University, Komuro 10281, Ina-machi, Saitama 362-0806 (Japan); Kojima, Hiroyuki; Takeuchi, Shinji [Hokkaido Institute of Public Health, Kita-19, Nishi-12, Kita-ku, Sapporo 060-0819 (Japan); Uramaru, Naoto [Nihon Pharmaceutical University, Komuro 10281, Ina-machi, Saitama 362-0806 (Japan); Sanoh, Seigo [Graduate School of Biomedical and Health Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8553 (Japan); Sugihara, Kazumi [Faculty of Pharmaceutical Science, Hiroshima International University, Koshingai 5-1-1, Kure, Hiroshima 737-0112 (Japan); Kitamura, Shigeyuki [Nihon Pharmaceutical University, Komuro 10281, Ina-machi, Saitama 362-0806 (Japan); Ohta, Shigeru [Graduate School of Biomedical and Health Sciences, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8553 (Japan)

2015-01-15

Benzophenone-3 (2-hydroxy-4-methoxybenzophenone; BP-3) is widely used as sunscreen for protection of human skin and hair from damage by ultraviolet (UV) radiation. In this study, we examined the metabolism of BP-3 by rat and human liver microsomes, and the estrogenic and anti-androgenic activities of the metabolites. When BP-3 was incubated with rat liver microsomes in the presence of NADPH, 2,4,5-trihydroxybenzophenone (2,4,5-triOH BP) and 3-hydroxylated BP-3 (3-OH BP-3) were newly identified as metabolites, together with previously detected metabolites 5-hydroxylated BP-3 (5-OH BP-3), a 4-desmethylated metabolite (2,4-diOH BP) and 2,3,4-trihydroxybenzophenone (2,3,4-triOH BP). In studies with recombinant rat cytochrome P450, 3-OH BP-3 and 2,4,5-triOH BP were mainly formed by CYP1A1. BP-3 was also metabolized by human liver microsomes and CYP isoforms. In estrogen reporter (ER) assays using estrogen-responsive CHO cells, 2,4-diOH BP exhibited stronger estrogenic activity, 2,3,4-triOH BP exhibited similar activity, and 5-OH BP-3, 2,4,5-triOH BP and 3-OH BP-3 showed lower activity as compared to BP-3. Structural requirements for activity were investigated in a series of 14 BP-3 derivatives. When BP-3 was incubated with liver microsomes from untreated rats or phenobarbital-, 3-methylcholanthrene-, or acetone-treated rats in the presence of NADPH, estrogenic activity was increased. However, liver microsomes from dexamethasone-treated rats showed decreased estrogenic activity due to formation of inactive 5-OH BP-3 and reduced formation of active 2,4-diOH BP. Anti-androgenic activity of BP-3 was decreased after incubation with liver microsomes. - Highlights: • Metabolic modification of the endocrine-disrupting activity of BP-3 was examined. • 2,4,5-TriOH BP and 3-OH BP-3 were identified as new BP-3 metabolites. • 2,4-DiOH BP and 2,3,4-triOH BP exhibited high or similar estrogenic activities. • Estrogenic activity of BP-3 was enhanced by incubation with rat liver

[Peroxide modification of membranes and isomorphic composition of cytochrome P-450 of rat liver microsomes during antioxidant deficiency].

Science.gov (United States)

Gubskiy, Iu I; Paramonova, G I; Boldeskul, A E; Primak, R G; Bogdanova, L A; Zadorina, O V; Litvinova, N V

1992-01-01

Lipid peroxidation (LPO), physico-chemical properties of the membranes and isoformic composition of microsomal cytochrome P-450 from the rat liver were studied under conditions of antioxidant insufficiency (AOI) which was modelled by exclusion of alpha-tocopherol from the animals' ration. An insignificant accumulation of microsomal diene conjugates and schiff bases against a sharp increase of the ability to the prooxidant stimulated LPO in vitro took place. A significant decrease of membrane lipid microviscosity and a change in surface properties of microsomal membranes of rats with AOI was determined. Absence of alpha-tocopherol in the ration was accompanied by a significant change in the content of separate isoforms of cytochrome P-450 exhibited in growth of a polypeptide with m. w. 54 kDa and the lowering of proteins with m. w. 48 and 50 kDa. Less intensive quenching of tryptophan fluorescence by acrylamide was also revealed, which testified to a lower accessibility of the quencher to membrane proteins or their fluorophore sites. Modification of lipid composition and of physicochemical properties of the rat liver membrane microsomes which was observed at AOI was significantly correlated by pretreatment with the antioxidant 4-methyl-2,6-ditretbutylphenol (ionol).

Effects of phenobarbital pretreatment on the in vivo metabolism of carbaryl in rats

International Nuclear Information System (INIS)

Knight, E.V.; Alvares, A.P.; Chin, B.H.

1987-01-01

Phenobarbital (PB) pretreatment of animals is known to induce the activity of drug-metabolizing enzymes in liver microsomes. Previous studies showed that incubation of carbaryl with microsomes obtained from livers of untreated or PB-treated rats resulted in little or no oxidative metabolism of the substrate. In addition, no spectral interactions were observed when carbaryl was added to hepatic microsomal suspensions. The present study was carried out to determine the effect of PB pretreatment on the in vivo metabolism of carbaryl in rats

Regulation of rat liver cytochrome P450j, a high affinity N-nitrosodimethylamine demethylase (NDMAD)

International Nuclear Information System (INIS)

Thomas, P.E.; Bandiera, S.; Maines, S.L.; Ryan, D.E.; Levin, W.

1987-01-01

Purified IgG from sera of rabbits immunized with homogeneous P450j was absorbed to produce monospecific anti-P450j. Results using anti-P450j in ELISA show that rat liver microsomal P450j content decreases between 3 and 6 wks of age in both sexes. Several xenobiotics (Aroclor 1254, mirex and 3-methylcholanthrene) repressed P450j levels when administered to male rats. In contrast, hepatic levels of P450j were induced by isoniazid, dimethylsulfoxide, pyrazole, 4-methylpyrazole, ethanol and chemically-induced diabetes. P450j levels were measurable in kidney, whereas this isozyme was barely detectable in lung, ovaries and testes; however, extra-hepatic P450j was inducible by isoniazid. Between 80-90% of microsomal NDMAD was inhibited by anti-P450j whether the microsomes were isolated from untreated rats or animals administered inducers or repressors of P450j. Results obtained with the reconstituted system suggest that the remaining microsomal NDMAD resistant to antibody inhibition is the result of the inaccessibility of a certain proportion of P450j due to interference by NADPH-P450 reductase. P450j content and NDMAD activity correlated well in microsomes from rats of all treatment groups. The evidence indicates that P450j is the primary, and possibly only, microsomal catalyst of NDMAD at substrate concentrations relevant to hepatocarcinogenesis induced by NDMA

Role of active oxygen species in the photodestruction of microsomal cytochrome P-450 and associated monooxygenases by hematoporphyrin derivative in rats

International Nuclear Information System (INIS)

Das, M.; Dixit, R.; Mukhtar, H.; Bickers, D.R.

1985-01-01

The cytochrome P-450 in hepatic microsomes prepared from rats pretreated with hematoporphyrin derivative was shown to be rapidly destroyed in the presence of long-wave ultraviolet light. The photocatalytic destruction of the heme-protein was dependent on both the dose of ultraviolet light and of hematoporphyrin derivative administered to the animals. The destructive reaction was accompanied by increased formation of cytochrome P-420, loss of microsomal heme content, and diminished catalytic activity of cytochrome P-450-dependent monooxygenases such as aryl hydrocarbon hydroxylase and 7-ethoxycoumarin O-deethylase. The specificity of the effect on cytochrome P-450 was confirmed by the observation that other heme-containing moieties such as myoglobin and cytochrome c were not susceptible to photocatalytic destruction. The destruction of cytochrome P-450 was a photodynamic process requiring oxygen since quenchers of singlet oxygen, including 2,5-dimethylfuran, histidine, and beta-carotene, each substantially diminished the reaction. Scavengers of superoxide anion such as superoxide dismutase and of H 2 O 2 such as catalase did not protect against photodestruction of cytochrome P-450, whereas inhibitors of the hydroxyl radical, including benzoate, mannitol, and ethyl alcohol, did afford protection. These results indicate that lipid-rich microsomal membranes and the heme-protein cytochrome P-450 embedded therein are potential targets of injury in cells exposed to hematoporphyrin derivative photosensitization

Microsomal aryl hydrocarbon hydroxylase comparison of the direct, indirect and radiometric assays

International Nuclear Information System (INIS)

Denison, M.S.; Murray, M.; Wilkinson, C.F.

1983-01-01

The direct fluorometric assay of aryl hydrocarbon hydroxlyase has been compared to the more commonly used indirect fluorometric and radiometric assays. Although rat hepatic microsomal activities measured by the direct assay were consistently higher than those obtained by the other assays, the relative changes in activity following enzyme induction and/or inhibition were similar. The direct assay provides an accurate and rapid measure of aryl hydrocarbon hydroxylase activity and avoids several problems inherent in the indirect and radiometric assays. 2 tables

In vitro inactivation of hepatic microsomal phospholipase A2 by the marine natural product manoalide

International Nuclear Information System (INIS)

Master, M.M.; Jacobs, R.S.

1986-01-01

The effects of manoalide (MLD) and several analogs (isolated from the sponge Luffariella variabilis) on mouse hepatic microsomal phospholipase A 2 (PLA 2 ) activity was investigated. Microsomal PLA 2 , a membrane bound, Ca ++ dependent enzyme with an alkaline pH optimum, functions in intracellular phospholipid turnover. In vitro PLA 2 activity was assayed by preincubating MLD or analogs (2.5-100μM) with microsomes for 60 min. at 37 0 C, combining this mixture with 14 C-phosphatidylcholine and CaCl 2 , and incubating at 37 0 C for 40 minutes. Enzyme activity was quantitated by measurement of the extracted 14 C-arachidonic acid product. MLD inhibited PLA 2 in a dose-dependent manner, with an IC 50 = 94μM. Lineweaver-Burk analysis suggests that MLD inhibits PLA 2 noncompetitively. One of the analogs, producing a comparable dose-response curve to MLD, was found to be more potent (IC 50 = 33μM). Another analog facilitated PLA 2 activity (15%) at 25μM, followed by inactivation at higher doses (IC 50 > 100 μM). Facilitation of PLA 2 activity was seen with concentrations as low as 2.5μM of a third analog, and significant inactivation of PLA 2 was evident. These results indicate that MLD is not as potent against microsomal PLA 2 as has been shown with purified bee venom and cobra venom PLA 2 's

Development of vitamin D3 25-hydroxylase activity in rat liver microsomes

International Nuclear Information System (INIS)

Thierry-Palmer, M.; Cullins, S.; Rashada, S.; Gray, T.K.; Free, A.

1986-01-01

The authors have determined the ontogeny of vitamin D 3 25-hydroxylase activity in rat liver microsomes. Microsomes from fetuses, neonates, and their mothers were incubated with 44 nM 3 H-vitamin D 3 in the presence of an NADPH generating system, oxygen, KCl, and MgCl 2 . Lipid extracts of the incubation samples were partially purified by thin-layer chromatography. Tritiated 25-hydroxy vitamin D 3 (250HD 3 ) was analyzed by high-pressure liquid chromatography using 94/6 hexane/isopropanol. Production rate for 250HD 3 in the mothers ranged from 0.22 to 0.30 pmol/mg protein/hr. Activities in the fetuses and neonates were 2.1, 12.9, 32.0, 35.8, and 71.0% of that of their mothers at -3, 0, 2, 7, and 15 days of age. The cytosolic fraction protected the substrate from degradation, stimulated the vitamin D 3 25-hydroxylase reaction in neonates and mothers (1.4 to 1.7 fold increase), and was absolutely required for 25-hydroxylase activity in fetuses. These data suggest that microsomal vitamin D 3 25-hydroxylase activity develops slowly and approaches full activity near the weaning stage. A cytosolic factor present as early as -3 days of age stimulates the activity of the microsomal vitamin D 3 25-hydroxylase

Evidence of a genetic basis for the different geographic occurrences of liver/kidney microsomal antibody type 1 in hepatitis C.

Science.gov (United States)

Muratori, Paolo; Czaja, Albert J; Muratori, Luigi; Granito, Alessandro; Guidi, Marcello; Ferri, Silvia; Volta, Umberto; Mantovani, Wilma; Pappas, Georgios; Cassani, Fabio; Lenzi, Marco; Bianchi, Francesco B

2007-01-01

Antibodies to liver/kidney microsome type 1 occur in Italian patients with hepatitis C, but rarely develop in North American patients. Our goals were to compare the frequencies of the HLA markers associated with autoimmune expression in Italian and North American patients with chronic hepatitis C and to determine genetic bases for regional differences in antibody production. HLA B8, DR3, DR4, DR7, DR11, DR13, DQ2, and the B8-DR3-DQ2 haplotype were determined by microlymphocytotoxicity and polymerase chain reaction in 105 Italian patients (50 with microsomal antibodies), 100 North American patients (none with microsomal antibodies), and Italian and North American healthy control subjects. Italian patients with microsomal antibodies differed from North American patients without these antibodies by having a higher frequency of HLA DR7 (54% vs. 27%, P=0.002). HLA DR7 occurred more frequently in seropositive Italian patients than in seronegative counterparts (54% vs. 11% P < 0.0001), Italian healthy control subjects (54% vs. 29%, P=0.0009), and North American healthy control subjects (54% vs. 19%, P < 0.0001). The frequency of HLA DR7 was similar in North American patients and controls (27% vs. 19%, P=0.2), but it was lower than in Italian controls (19% vs. 29%, P=0.059). Seropositive Italian patients had a lower frequency of HLA DR11 than seronegative Italian patients and Italian controls (18% vs. 34%, P=0.07, and 18% vs. 35%, P=0.02, respectively). In contrast to seropositive Italian patients, North American patients had HLA DR4 (30% vs. 12%, P=0.02), HLA DR13 (29% vs. 10%, P=0.01), and the B8-DR3-DQ2 haplotype (23% vs. 6%, P=0.01) more often. Similarly, HLA DR4 and the B8-DR3-DQ2 phenotype were more frequent in North American patients than in Italian controls (30% vs. 16%, P=0.005, and 23% vs. 7%, P=0.00002, respectively). HLA DR7 is associated with the development of microsomal antibodies in Italian patients with chronic hepatitis C. The lower frequency of HLA DR7

Environmentally persistent free radicals inhibit cytochrome P450 activity in rat liver microsomes

Energy Technology Data Exchange (ETDEWEB)

Reed, James R., E-mail: rreed@lsuhsc.edu [Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Science Center, 533 Bolivar St., New Orleans, LA 70112 (United States); The Stanley S. Scott Cancer Center, Louisiana State University Health Science Center, 533 Bolivar St., New Orleans, LA 70112 (United States); Cawley, George F.; Ardoin, Taylor G. [Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Science Center, 533 Bolivar St., New Orleans, LA 70112 (United States); The Stanley S. Scott Cancer Center, Louisiana State University Health Science Center, 533 Bolivar St., New Orleans, LA 70112 (United States); Dellinger, Barry; Lomnicki, Slawomir M.; Hasan, Farhana; Kiruri, Lucy W. [Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803 (United States); Backes, Wayne L. [Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Science Center, 533 Bolivar St., New Orleans, LA 70112 (United States); The Stanley S. Scott Cancer Center, Louisiana State University Health Science Center, 533 Bolivar St., New Orleans, LA 70112 (United States)

2014-06-01

Combustion processes generate particulate matter that affects human health. When incineration fuels include components that are highly enriched in aromatic hydrocarbons (especially halogenated varieties) and redox-active metals, ultrafine particulate matter containing air-stable, environmentally persistent free radicals (EPFRs) is generated. The exposure to fine EPFRs (less than 2.5 μm in diameter) has been shown to negatively influence pulmonary and cardiovascular functions in living organisms. The goal of this study was to determine if these EPFRs have a direct effect on cytochrome P450 function. This was accomplished by direct addition of the EPFRs to rat liver microsomal preparations and measurement of several P450 activities using form-selective substrates. The EPFRs used in this study were formed by heating vapors from an organic compound (either monochlorophenol (MCP230) or 1,2-dichlorobenzene (DCB230)) and 5% copper oxide supported on silica (approximately 0.2 μm in diameter) to 230 °C under vacuum. Both types of EPFRs (but not silica, physisorbed silica, or silica impregnated with copper oxide) dramatically inhibited the activities of CYP1A, CYP2B, CYP2E1, CYP2D2 and CYP3A when incubated at concentrations less than 0.1 mg/ml with microsomes and NADPH. Interestingly, at the same concentrations, the EPFRs did not inhibit HO-1 activity or the reduction of cytochrome c by NADPH-cytochrome P450 reductase. CYP2D2-selective metabolism by rat liver microsomes was examined in more detail. The inhibition of CYP2D2-selective metabolism by both DCB230- and MCP230-EPFRs appeared to be largely noncompetitive and was attenuated in the presence of catalase suggesting that reactive oxygen species may be involved in the mechanism of inhibition. - Highlights: • Combustion of organic pollutants generates long-lived particulate radicals (EPFRs). • EPFRs inhibit metabolism by all cytochromes P450 tested in rat liver microsomes. • EPFR-mediated inhibition is related to

Environmentally persistent free radicals inhibit cytochrome P450 activity in rat liver microsomes

International Nuclear Information System (INIS)

Reed, James R.; Cawley, George F.; Ardoin, Taylor G.; Dellinger, Barry; Lomnicki, Slawomir M.; Hasan, Farhana; Kiruri, Lucy W.; Backes, Wayne L.

2014-01-01

Combustion processes generate particulate matter that affects human health. When incineration fuels include components that are highly enriched in aromatic hydrocarbons (especially halogenated varieties) and redox-active metals, ultrafine particulate matter containing air-stable, environmentally persistent free radicals (EPFRs) is generated. The exposure to fine EPFRs (less than 2.5 μm in diameter) has been shown to negatively influence pulmonary and cardiovascular functions in living organisms. The goal of this study was to determine if these EPFRs have a direct effect on cytochrome P450 function. This was accomplished by direct addition of the EPFRs to rat liver microsomal preparations and measurement of several P450 activities using form-selective substrates. The EPFRs used in this study were formed by heating vapors from an organic compound (either monochlorophenol (MCP230) or 1,2-dichlorobenzene (DCB230)) and 5% copper oxide supported on silica (approximately 0.2 μm in diameter) to 230 °C under vacuum. Both types of EPFRs (but not silica, physisorbed silica, or silica impregnated with copper oxide) dramatically inhibited the activities of CYP1A, CYP2B, CYP2E1, CYP2D2 and CYP3A when incubated at concentrations less than 0.1 mg/ml with microsomes and NADPH. Interestingly, at the same concentrations, the EPFRs did not inhibit HO-1 activity or the reduction of cytochrome c by NADPH-cytochrome P450 reductase. CYP2D2-selective metabolism by rat liver microsomes was examined in more detail. The inhibition of CYP2D2-selective metabolism by both DCB230- and MCP230-EPFRs appeared to be largely noncompetitive and was attenuated in the presence of catalase suggesting that reactive oxygen species may be involved in the mechanism of inhibition. - Highlights: • Combustion of organic pollutants generates long-lived particulate radicals (EPFRs). • EPFRs inhibit metabolism by all cytochromes P450 tested in rat liver microsomes. • EPFR-mediated inhibition is related to

The influence of single application of paracetamol and/or N-acetylcysteine on rats subchronic exposed to trichloroethylene vapours. I. Effect on hepatic moonooxygenase system dependent of cytochrome P450

Directory of Open Access Journals (Sweden)

Andrzej Plewka

2012-06-01

Full Text Available Background: There is a number of factors which potentially affect occurrence of toxic change in liver after overdosing of paracetamol. Hepatic metabolism of trichloroethylene has primary impact on hepatotoxic effect of this solvent. This means that the combined exposure to these xenobiotics can be particularly harmful for human. The influence of N-acetylcysteine (NAC as a protective factor after paracetamol intoxication was studies. Materials and method: Tests were carried out on rats which were treated with trichloroethylene, paracetamol and/or N-acetylcysteine. In the hepatic microsomal fraction activity of the components of cytochrome P450- dependent monooxygenases was determined Results: Paracetamol slightly stimulated cytochrome P450 having no effect on reductase activity cooperating with it. Cytochrome b5 and its reductase were inhibited by this compound. Trichloroethylene was the inhibitor of compounds of II microsomal electron transport chain. N-acetylcysteine inhibited activity of reductase of NADH-cytochrome b5. Conclusions: Tested doses of the xenobiotics influenced on II microsomal electron transport chain. Protective influence of N-acetylcysteine was better if this compound was applied 2 hours after exposure on xenobiotics

Frequency and significance of antibodies to liver/kidney microsome type 1 in adults with chronic active hepatitis.

Science.gov (United States)

Czaja, A J; Manns, M P; Homburger, H A

1992-10-01

To assess the frequency of antibodies to liver/kidney microsome type 1 (anti-LKM1) in patients with chronic active hepatitis, 131 such patients were tested by an indirect immunofluorescence assay. Of 62 patients with type 1 autoimmune hepatitis, none were seropositive. In contrast, 3 of 11 patients with autoimmune hepatitis and antimitochondrial antibodies (27%) were seropositive for anti-LKM1. Each had responded to corticosteroid therapy, and retesting of sera confirmed that each had been misclassified as antimitochondrial antibody positive. None of the patients with chronic active hepatitis B (14 patients) or C (24 patients) had anti-LKM1. Similarly, none of the 20 patients with cryptogenic disease had these antibodies. It is concluded that anti-LKM1 is specific for type 2 autoimmune hepatitis and is infrequent in adult patients seen at a referral center in the United States for chronic active hepatitis. Anti-LKM1 reactivity may be misinterpreted as antimitochondrial antibody reactivity by indirect immunofluorescence. Chronic hepatitis B and C virus infections are not important stimuli for the production of anti-LKM1, and testing for anti-LKM 1 is unlikely to clarify the nature of cryptogenic disease.

Modulation of catechol estrogen synthesis by rat liver microsomes: effects of treatment with growth hormone or testosterone

International Nuclear Information System (INIS)

Quail, J.A.; Jellinck, P.H.

1987-01-01

The ability of GH from various mammalian species, administered to normal mature male rats by constant infusion, to decrease the hepatic 2-hydroxylation of estradiol (E2) to female levels, as measured by the release of 3 H 2 O from [2-3H]E2, was determined. Rat and human GH (hGH) showed the highest activity while ovine GH was inactive. PRL (0.6 IU/h X kg) administered together with hGH (0.02 IU/h X kg) did not antagonize the feminizing action of GH. Infusion of hGH into male rats decreased the affinity of estradiol 2-hydroxylase for its steroid substrate and altered the linear Lineweaver-Burk plot towards a nonlinear hyperbolic plot characteristic of the female. The apparent Michaelis-Menten constant (Km) for the reaction was 1.69 microM for males and 2.75 microM for testosterone-treated ovariectomized females. An equal mixture of liver microsomes from male and female rats gave kinetic values similar to those observed with males alone. Neonatal imprinting with androgen did not alter the magnitude of the response of female rats to treatment with testosterone and/or GH at maturity and the androgen effect could only be shown in ovariectomized animals. The results with rats of different endocrine status were corroborated by the kinetic data and by the pattern of metabolites obtained with [4- 14 C]E2 when examined by TLC and autoradiography. The hormonal control of estradiol 2-hydroxylase, the key enzyme in catechol estrogen formation, and the contribution of sex-specific multiple forms of the enzyme to this reaction are discussed

In vitro inactivation of hepatic microsomal phospholipase A/sub 2/ by the marine natural product manoalide

Energy Technology Data Exchange (ETDEWEB)

Master, M.M.; Jacobs, R.S.

1986-03-01

The effects of manoalide (MLD) and several analogs (isolated from the sponge Luffariella variabilis) on mouse hepatic microsomal phospholipase A/sub 2/ (PLA/sub 2/) activity was investigated. Microsomal PLA/sub 2/, a membrane bound, Ca/sup + +/ dependent enzyme with an alkaline pH optimum, functions in intracellular phospholipid turnover. In vitro PLA/sub 2/ activity was assayed by preincubating MLD or analogs (2.5-100..mu..M) with microsomes for 60 min. at 37/sup 0/C, combining this mixture with /sup 14/C-phosphatidylcholine and CaCl/sub 2/, and incubating at 37/sup 0/C for 40 minutes. Enzyme activity was quantitated by measurement of the extracted /sup 14/C-arachidonic acid product. MLD inhibited PLA/sub 2/ in a dose-dependent manner, with an IC/sub 50/ = 94..mu..M. Lineweaver-Burk analysis suggests that MLD inhibits PLA/sub 2/ noncompetitively. One of the analogs, producing a comparable dose-response curve to MLD, was found to be more potent (IC/sub 50/ = 33..mu..M). Another analog facilitated PLA/sub 2/ activity (15%) at 25..mu..M, followed by inactivation at higher doses (IC/sub 50/ > 100 ..mu..M). Facilitation of PLA/sub 2/ activity was seen with concentrations as low as 2.5..mu..M of a third analog, and significant inactivation of PLA/sub 2/ was evident. These results indicate that MLD is not as potent against microsomal PLA/sub 2/ as has been shown with purified bee venom and cobra venom PLA/sub 2/'s.

Induction of hepatic aryl hydrocarbon hydroxylase and epoxide hydrase in Wistar rats pretreated with oral methadone hydrochloride.

Science.gov (United States)

Bellward, G D; Gontovnick, L S; Otten, M

1977-01-01

Methadone-HCl added to the drinking water of adult female Wistar rats for 4 weeks produced an increase in the aryl hydrocarbon hydroxylase activity of the hepatic microsomal fraction to 222% of control levels. No change was seen in epoxide hydrase activity. In contrast, when male rats were treated similarly, there was an increase in epoxide hydrase activity to 212% of controls with no change in aryl hydrocarbon hydroxylase activity. No such changes were observed when the subcutaneous route of administration or chronic, low-dose, intraperitoneal injections were used. There were no differences in hepatic cytochrome P-450 or protein concentrations in treated animals as compared to their respective control groups. Control studies were carried out with quinine sulfate in the drinking water to decrease water intake to the level of the methadone-treated group. No elevation in either enzyme activity occurred in this control group. Similarly, paired-feeding studies showed the elevation of enzyme activity to be due to the methadone, not food deprivation. The effects of concurrent therapy of methadone with phenobarbital sodium or 3-methylcholanthrene were compared.

Increase in covalent binding of 5-hydroxydiclofenac to hepatic tissues in rats co-treated with lipopolysaccharide and diclofenac: involvement in the onset of diclofenac-induced idiosyncratic hepatotoxicity.

Science.gov (United States)

Kishida, Tomoyuki; Onozato, Tomoya; Kanazawa, Toru; Tanaka, Satoru; Kuroda, Junji

2012-01-01

Diclofenac (DCF), a nonsteroidal anti-inflammatory drug, is well known to induce idiosyncratic hepatotoxicity. Although there remains much to be elucidated about its onset mechanism, it is widely accepted as a hypothesis that idiosyncratic hepatotoxicity arises from a specific immune response to a hapten formed by covalent binding of drugs or their reactive metabolites to hepatic tissues. In this study, we investigated the effects of covalent binding of DCF reactive metabolites to hepatic tissues using a rat model of liver injury induced by co-treatment with lipopolysaccharide (LPS) at a non-hepatotoxic dose. In studies done in vitro using hepatic microsomes prepared from rats treated with LPS alone, 4'- and 5-hydroxylation activities on DCF metabolism and adducts of reactive metabolites to dansyl glutathione (dGSH) were markedly decreased associated with a decrease in total P450 content. However, in studies done in vivo, the LPS/DCF co-treatment significantly increased adducts of 5-hydroxydiclofenac (5-OH-DCF) to rat hepatic tissues and delayed the elimination of 5-OH-DCF from plasma. Furthermore, we investigated the effects of co-treatment on hepatic GSH level in rats. A decrease of hepatic GSH was observed with the LPS/DCF co-treatment but not with LPS or DCF alone. The results suggest that covalent binding of reactive metabolites via 5-OH-DCF to hepatic tissues may play an important role in the onset of DCF-induced idiosyncratic hepatotoxicity, especially under decreased GSH conditions.

Distinct ontogenic patterns of overt and latent DGAT activities of rat liver microsomes.

Science.gov (United States)

Waterman, Ian J; Price, Nigel T; Zammit, Victor A

2002-09-01

We have studied the ontogeny of the two functional diacylglycerol acyltransferase (DGAT) activities (overt and latent) during postnatal development in rat liver. We find that the ontogenic patterns of the two are highly distinct. Overt DGAT shows a transient rise in activity up to day 4 postnatally, after which it declines until weaning; thereafter, it increases steadily to reach high adult values that may contribute to the high rates of turnover of cytosolic triacylglycerol (TAG). By contrast, latent DGAT activity increases continuously during the suckling period but falls sharply upon weaning onto chow but not onto a high-fat diet. Rates of TAG secretion by hepatocytes are higher than in the adult during the first 7 days after birth, and are largely dependent on the mobilization of the abundant intrahepatocyte TAG as a source of acyl moieties. When the hepatic steatosis is cleared (after day 7) the TAG secretion rate declines by 80% to reach adult values. Quantification of the content of mRNA for the DGAT1 and DGAT2 genes does not show correlation with either of the DGAT activities. We conclude that post-translational modification may play an important role in the overt and latent distribution of DGAT activity in the liver microsomal membrane.

2,2',3,3',6,6'-Hexachlorobiphenyl (PCB 136) is Enantioselectively Oxidized to Hydroxylated Metabolites by Rat Liver Microsomes

Science.gov (United States)

Wu, Xianai; Pramanik, Ananya; Duffel, Michael W.; Hrycay, Eugene G.; Bandiera, Stelvio M.; Lehmler, Hans-Joachim; Kania-Korwel, Izabela

2011-01-01

Developmental exposure to multiple-ortho substituted polychlorinated biphenyls (PCBs) causes adverse neurodevelopmental outcomes in laboratory animals and humans by mechanisms involving the sensitization of Ryanodine receptors (RyRs). In the case of PCB 136, the sensitization of RyR is enantiospecific, with only (-)-PCB 136 being active. However, the role of enantioselective metabolism in the developmental neurotoxicity of PCB 136 is poorly understood. The present study employed hepatic microsomes from phenobarbital (PB-), dexamethasone (DEX-) and corn oil (VEH-)treated male Sprague-Dawley rats to investigate the hypothesis that PCB 136 atropisomers are enantioselectively metabolized by P450 enzymes to potentially neurotoxic, hydroxylated PCB 136 metabolites. The results demonstrated the time- and isoform-dependent formation of three metabolites, with 5-OH-PCB 136 (2,2',3,3',6,6'-hexachlorobiphenyl-5-ol) being the major metabolite. The formation of 5-OH-PCB 136 increased with the activity of P450 2B enzymes in the microsomal preparation, which is consistent with PCB 136 metabolism by rat P450 2B1. The minor metabolite 4-OH-PCB 136 (2,2',3,3',6,6'-hexachlorobiphenyl-4-ol) was produced by a currently unidentified P450 enzymes. An enantiomeric enrichment of (-)-PCB 136 was observed in microsomal incubations due to the preferential metabolism of (+)-PCB 136 to the corresponding 5-OH-PCB 136 (2,2',3,3',6,6'-hexachlorobiphenyl-5-ol) atropisomer. 4-OH-PCB 136 displayed an enrichment of the atropisomer formed from (-)-PCB 136; however, the enrichment of this metabolite atropisomer didn't affect the enantiomeric enrichment of the parent PCB because 4-OH-PCB 136 is only a minor metabolite. Although the formation of 5- and 4-OH-PCB 136 atropisomers increased with time, the enantioselective formation of the OH-PCB metabolites resulted in constant enantiomeric enrichment, especially at later incubation times. These observations not only demonstrate that the chiral signatures of

Sex difference in induction of hepatic CYP2B and CYP3A subfamily enzymes by nicardipine and nifedipine in rats

International Nuclear Information System (INIS)

Konno, Yoshihiro; Sekimoto, Masashi; Nemoto, Kiyomitsu; Degawa, Masakuni

2004-01-01

Male and female of F344 rats were treated per os with nicardipine (Nic) and nifedipine (Nif), and changes in the levels of mRNA and protein of hepatic cytochrome P450 (P450) enzymes, CYP2B1, CYP2B2, CYP3A1, CYP3A2, CYP3A9, and CYP3A18 were examined. Furthermore, hepatic microsomal activities for pentoxyresorufin O-dealkylation (PROD) and nifedipine oxidation, which are mainly mediated by CYP2B and CYP3A subfamily enzymes, respectively, were measured. Analyses of RT-PCR and Western blotting revealed that Nic and Nif induced predominantly CYP3A and CYP2B enzymes, respectively. As for the gene activation of CYP2B enzymes, especially CYP2B1, Nif showed high capacity in both sexes of rats, whereas Nic did a definite capacity in the males but little in the females. Gene activations of CYP3A1, CYP3A2, and CYP3A18 by Nic occurred in both sexes of rats, although that of CYP3A9 did only in the male rats. Although gene activations of CYP3A1 and CYP3A2 by Nif were observed in both sexes of rats, a slight activation of the CYP3A9 gene occurred only in female rats, and the CYP3A18 gene activation, in neither male nor female rats. Thus, changes in levels of the mRNA or protein of CYP2B and CYP3A enzymes, especially CYP2B1 and CYP3A2, were closely correlated with those in hepatic PROD and nifedipine oxidation activities, respectively. The present findings demonstrate for the first time the sex difference in the Nic- and Nif-mediated induction of hepatic P450 enzymes in rats and further indicate that Nic and Nif show different specificities and sex dependencies in the induction of hepatic P450 enzymes

Role of metabolic activation by cytochrome P-450 in covalent binding of VP 16-213 to rat liver and HeLa cell microsomal proteins

Energy Technology Data Exchange (ETDEWEB)

van Maanen, J.M.; de Ruiter, C.; de Vries, J.; Kootstra, P.R.; Gobas, F.; Pinedo, H.M.

1985-09-01

Covalent binding of /sup 3/H-labeled VP 16-213 to rat liver and HeLa cell microsomal proteins was studied in vitro. Metabolic activation by cytochrome P-450 was found to play a role in the covalent binding of VP 16-213 to rat liver microsomal proteins, as shown by the need of NADPH cofactor, the increased binding after phenobarbital pretreatment and the inhibition by SFK-525A. Addition of ascorbic acid or alpha-phenyl-N-tert. butylnitrone to the incubation mixture depressed covalent binding by about 85%, suggesting that formation of a reactive metabolite from the phenolic structure may be involved in the binding process. VP 16-213 did not inhibit aminopyrine N-demethylase at the concentration used in the binding experiments (17 microM), indicating that metabolism of its methylenedioxy group does not play a role in binding to microsomal proteins. HeLa cell microsomes were found to possess aminopyrine N-demethylase activity. Covalent binding of radiolabeled VP 16-213 to HeLa cell microsomes decreased by about 64% if NADPH was omitted.

Mutagenic activation and detoxification of benzo[a]pyrene in vitro by hepatic cytochrome P450 1A1 and phase II enzymes in three meat-producing animals.

Science.gov (United States)

Darwish, W; Ikenaka, Y; Eldaly, E; Ishizuka, M

2010-01-01

The mutagenic activation activity of hepatic microsomes from three meat-producing animals (cattle, deer and horses) was compared with those of rats as a reference species. In the Ames Salmonella typhimurium TA98 assay, the liver microsomes of all examined animals mutagenically activated benzo[a]pyrene, an ideal promutagens, in terms of production of histidine-independent revertant colonies. The microsomes of horses had the highest ability to produce revertant colonies of the examined animals under both low and high substrate concentrations. Inhibition of this mutagenic activity using alpha-naphthoflavone, anti-rat CYP1A1, CYP3A2 and CYP2E1 antibodies suggests that this activity was mainly because of CYP1A1 in these animals as well as in rats. The addition of co-factors for two phase II enzymes, microsomal UDP glucoronosyl transferase and cytosolic glutathione-S-transferase, reduced the production of the revertant colonies in a concentration-dependent manner. Interestingly, horses had the highest reduction rate among the examined animals, suggesting that phase II enzymes play a great role in producing a state of balance between the bioactivation and detoxification of xenobiotics in these meat-producing animals. This report is the first to investigate the mutagenic activation activity of the hepatic microsomes and the role of phase II enzymes against this activity in meat-producing animals. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Microsomal metabolism of trenbolone acetate metabolites ...

Science.gov (United States)

Trenbolone acetate (TBA) is a synthetic growth promoter widely used in animal agriculture, and its metabolites are suspected endocrine disrupting compounds in agriculturally impacted receiving waters. However, beyond the three widely recognized TBA metabolites (17-trenbolone, 17-trenbolone and trendione), little is known about other metabolites formed in vivo and subsequently discharged into the environment, with some evidence suggesting these unknown metabolites comprise a majority of the TBA mass dosed to the animal. Here, we explored the metabolism of the three known TBA metabolites using rat liver microsome studies. All TBA metabolites are transformed into a complex mixture of monohydroxylated products. Based on product characterization, the majority are more polar than the parent metabolites but maintain their characteristic trienone backbone. A minor degree of interconversion between known metabolites was also observed, as were higher order hydroxylated products with a greater extent of reaction. Notably, the distribution and yield of products were generally comparable across a series of variably induced rat liver microsomes, as well as during additional studies with human and bovine liver microsomes. Bioassays conducted with mixtures of these transformation products suggest that androgen receptor (AR) binding activity is diminished as a result of the microsomal treatment, suggesting that the transformation products are generally less potent than

Rat liver microsomal cytochrome P450-dependent oxidation of 3,5-disubstituted analogues of paracetamol

NARCIS (Netherlands)

Bessems, J.G.M.; Koppele, J.M. te; Dijk, P.A. van; Stee, L.L.P. van; Commandeur, J.N.M.; Vermeulen, N.P.E.

1996-01-01

1. The cytochrome P450-dependent binding of paracetamol and a series of 3,5-disubstituted paracetamol analogues (R = -F, -Cl, -Br, -I, -C(H)3, -C2H5, -iC3H7) have been determined with β-naphthoflavone (βNF)-induced rat liver microsomes and produced reverse type I spectral changes. K(s,app) varied

Studies on estradiol-2/4-hydroxylase activity in rat brain and liver

International Nuclear Information System (INIS)

Theron, C.N.

1985-03-01

A sensitive and specific radio-enzymatic assay was used to study estradiol-2/4-hydroxylase activity in rat liver microsomes and in microsomes obtained from 6 discrete brain areas of the rat. Kinetic parameters were determined for these enzyme activities. The effects of different P-450 inhibitors on estradiol-2/4-hydroxylase activity in brain and liver microsomes were also studied. In both organs these enzyme activities were found to be located mainly in the microsomal fraction and were inhibited by the 3 P-450 inhibitors tested. The hepatic estradiol-2/4-hydroxylase activity in adult male rats was significantly higher than that of females, but the enzyme activity in the brain did not exhibit a similar sex difference. Furthermore, estradiol-2/4-hydroxylase activity in rat liver was strongly induced by phenobarbitone treatment, but not in the brain. The phenobarbitone-induced activity in male and female rats exhibited significant kinetic differences. In female rats sexual maturation was associated with significant changes in the apparent Km of estradiol-2/4-hydroxylases in the liver and hypothalamus. Evidence was found that the in vitro estradiol-2/4-hydroxylase activity in rat brain and liver is due to more than one form of microsomal P-450. Kinetic studies showed important differences between the estradiol-2/4-hydroxylase activities in the hippocampus and hypothalamus. Significant differences in estradiol-2/4-hydroxylase activities were observed in the 6 brain areas studied, with the hippocampus showing the highest, and the hypothalamus the lowest activity at all developmental stages in both male and female rats

In vitro metabolism of the anti-androgenic fungicide vinclozolin by rat liver microsomes.

Science.gov (United States)

Sierra-Santoyo, Adolfo; Angeles-Soto, Esperanza; de Lourdes López-González, Ma; Harrison, Randy A; Hughes, Michael F

2012-03-01

Vinclozolin (V) is a fungicide used in agricultural settings. V administered to rats is hydrolyzed to 2-[[(3,5-dichlorophenyl)-carbamoyl]oxy]-2-methyl-3-butenoic acid (M1) and 3',5'-dichloro-2-hydroxy-2-methylbut-3-enanilide (M2). V, M1 and M2 have antiandrogenic properties by interacting with the androgen receptor. Data on V, M1 and M2 biotransformation are limited. Our objective was to characterize V metabolism by rat liver microsomes. V was incubated with non-treated adult male Long-Evans rat liver microsomes and NADPH. Several metabolites were detected following the extraction of incubate with acetonitrile and analysis by HPLC/DAD/MSD. One metabolite was identified as [3-(3,5-dichlorophenyl)-5-methyl-5-(1,2-dihydroxyethyl)-1,3-oxazolidine-2,4-dione] (M4), which was gradually converted to 3',5'-dichloro-2,3,4-trihydroxy-2-methylbutylanilide (M5). Both co-eluted in the same HPLC peak. Another metabolite ([M7]) was detected by UV but was unstable for mass spectral analysis. The K(M app) for co-eluted M4/M5 and [M7] was 53.7 and 135.4 μM, the V(max app) was 0.812 and 0.669 nmoles/min/mg protein, and CL(int) was 15.1 and 4.9 ml/min/g protein, respectively. Pilocarpine, orphenadrine and proadifen and anti-rat cytochrome P450 (CYP)2A, 2B and 3A antibodies inhibited M4/M5 and [M7] formation. These results indicate that V is efficiently metabolized by CYP. Determination of the metabolites of V will provide further insight into the relationship between toxicity and tissue dose of V and its metabolites.

The effect of dietary glycine on the hepatic tumor promoting activity of polychlorinated biphenyls (PCBs) in rats

International Nuclear Information System (INIS)

Bunaciu, Rodica Petruta; Tharappel, Job C.; Lehmler, Hans-Joachim; Kania-Korwel, Izabela; Robertson, Larry W.; Srinivasan, Cidambi; Spear, Brett T.; Glauert, Howard P.

2007-01-01

Polychlorinated biphenyls (PCBs) are ubiquitious lipophilic environmental pollutants. Some of the PCB congeners and mixtures of congeners have tumor promoting activity in rat liver. The mechanism of their activity is not fully understood and is likely to be multifactorial. The aim of this study was to investigate if the resident liver macrophages, Kupffer cells, are important in the promoting activity of PCBs. The hypothesis of this study was that the inhibition of Kupffer cell activity would inhibit hepatic tumor promotion by PCBs in rats. To test our hypothesis, we studied the effects of Kupffer cell inhibition by dietary glycine (an inhibitor of Kupffer cell secretory activity) in a rat two-stage hepatocarcinogenesis model using 2,2',4,4',5,5'-hexachlorobiphenyl (PCB-153, a non-dioxin-like PCB) or 3,3',4,4'-tetrachlorobiphenyl (PCB-77, a dioxin-like PCB) as promoters. Diethylnitrosamine (DEN, 150 mg/kg) was administered to female Sprague-Dawley rats, which were then placed on an unrefined diet containing 5% glycine (or casein as nitrogen control) starting two weeks after DEN administration. On the third day after starting the diets, rats received PCB-77 (300 μmol/kg), PCB-153 (300 μmol/kg), or corn oil by i.p. injection. The rats received a total of 4 PCB injections, administered every 14 days. The rats were euthanized on the 10th day after the last PCB injection, and the formation of altered hepatic foci expressing placental glutathione S-transferase (PGST) and the rate of DNA synthesis in these foci and in the normal liver tissue were determined. Glycine did not significantly affect foci number or volume. PCB-153 did not significantly increase the focal volume, but increased the number of foci per liver, but only in the rats not fed glycine; PCB-77 increased both the foci number and their volume in both glycine-fed and control rats. Glycine did not alter the PCB content of the liver, but did increase the activity of 7-benzyloxyresorufin O-dealkylase (BROD

In vitro metabolism and bioactivation of 1,2,3-trichloropropane.

Science.gov (United States)

Weber, G L; Sipes, I G

1992-03-01

In vitro studies using rat and human hepatic microsomes have shown that the halogenated hydrocarbon 1,2,3-trichloropropane (TCP) is bioactivated to the direct acting mutagen 1,3-dichloroacetone (DCA). The presence of DCA in microsomal incubations was confirmed by gas chromatography-mass spectrometry. DCA formation was totally dependent on the presence of NADPH. The rate of DCA formation using rat and human microsomes was 0.268 +/- 0.029 and 0.026 +/- 0.006 nmol/min/mg protein +/- SE, respectively. When hepatic microsomes were isolated from rats pretreated with the cytochrome P-450 inducers, phenobarbital, and dexamethasone, 24- and 2.5-fold increases, respectively, in the rate of DCA production, were observed. Pretreatment with beta-naphthoflavone resulted in a 50% inhibition in DCA formation. The inhibitors of cytochromes P-450, SKF 525-A and 1-aminobenzotriazol, produced 85 and 70% inhibitions of DCA formation, respectively. When alcohol dehydrogenase and NADH were added to microsomal incubations, two TCP-related alcohols, 1,3-dichloro-2-propanol and 2,3-dichloropropanol, were formed. These alcohols are products of the initial microsomal metabolites, DCA and 2,3-dichloropropanal. [14C]TCP equivalents bound covalently to rat hepatic microsomal protein. This binding was increased 8-fold when hepatic microsomes from phenobarbital pretreated rats were used. The addition of either glutathione or N-acetylcysteine to the incubations completely inhibited this binding. In the presence of N-acetylcysteine, 1,3-(2-propanone)-bis-S-(N-acetylcysteine) (PDM) was the only N-acetylcysteine conjugate detected. It represented 87% of TCP microsomal metabolism. The formation of PDM implicates DCA as the major microsomal protein-binding metabolite of TCP. The formation of DCA, a direct-acting mutagen, may be responsible for the mutagenicity of TCP in systems using rat hepatic microsomes. Its role in the tumorigenicity and carcinogenicity of TCP remains to be established.

Metabolism of ginger component [6]-shogaol in liver microsomes from mouse, rat, dog, monkey, and human.

Science.gov (United States)

Chen, Huadong; Soroka, Dominique; Zhu, Yingdong; Sang, Shengmin

2013-05-01

There are limited data on the metabolism of [6]-shogaol (6S), a major bioactive component of ginger. This study demonstrates metabolism of 6S in liver microsomes from mouse, rat, dog, monkey, and human. The in vitro metabolism of 6S was compared among five species using liver microsomes from mouse, rat, dog, monkey, and human. Following incubations with 6S, three major reductive metabolites 1-(4'-hydroxy-3'-methoxyphenyl)-4-decen-3-ol (M6), 1-(4'-hydroxy-3'-methoxyphenyl)-decan-3-ol (M9), and 1-(4'-hydroxy-3'-methoxyphenyl)-decan-3-one (M11), as well as two new oxidative metabolites (1E,4E)-1-(4'-hydroxy-3'-methoxyphenyl)-deca-1,4-dien-3-one (M14) and (E)-1-(4'-hydroxy-3'-methoxyphenyl)-dec-1-en-3-one (M15) were found in all species. The kinetic parameters of M6 in liver microsomes from each respective species were quantified using Michaelis-Menten theory. A broad CYP-450 inhibitor, 1-aminobenzotriazole, precluded the formation of oxidative metabolites, M14 and M15, and 18β-glycyrrhetinic acid, an aldo-keto reductase inhibitor, eradicated the formation of the reductive metabolites M6, M9, and M11 in all species. Metabolites M14 and M15 were tested for cancer cell growth inhibition and induction of apoptosis and both showed substantial activity, with M14 displaying greater potency than 6S. We conclude that 6S is metabolized extensively in mammalian species mouse, rat, dog, monkey, and human, and that there are significant interspecies differences to consider when planning preclinical trials toward 6S chemoprevention. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Perfluorodecanoic acid enhances the formation of oleic acid in rat liver.

Science.gov (United States)

Yamamoto, A; Kawashima, Y

1997-01-01

The feeding of perfluorodecanoic acid (PFDA) to male rats at a dietary concentration of 0.005% (w/w) for 7 days resulted in a marked increase in the activity of microsomal stearoyl-CoA desaturation in the liver. This increase in the overall desaturation activity was due to the induction of terminal desaturase among the components comprising the desaturation system. In contrast, PFDA inhibited desaturation in vitro, seemingly due to interference with electron transport through the desaturation system. Accordingly, PFDA can be an inducer and also an inhibitor of delta9-desaturation. PFDA feeding enhanced the conversion of radioactive stearic acid into oleic acid in the liver in vivo, indicating that the induction of delta9-desaturase by PFDA functions in vivo. PFDA feeding increased the mass of octadecenoic acid (C18:1) in the liver and the proportion of C18:1 in microsomal lipid. A highly significant linear correlation existed between the microsomal desaturase activity and the proportion of C18:1 in microsomal lipid when compared using rats in five different physiological states: control, PFDA-fed, p-chlorophenoxyisobutyric acid (clofibric acid)-fed, starved and starved/refed. These results suggest that the increase in the hepatic level of C18:1 caused by feeding of PFDA to rats can be explained by the common concept of regulation, i.e. the hepatic level of C18:1 is under the control of delta9-desaturase. The dietary administration of PFDA also increased the content of cytochrome P-450 and the activity of 7-ethoxycoumarin O-de-ethylase in the liver. PMID:9230124

Clearance Prediction Methodology Needs Fundamental Improvement: Trends Common to Rat and Human Hepatocytes/Microsomes and Implications for Experimental Methodology.

Science.gov (United States)

Wood, F L; Houston, J B; Hallifax, D

2017-11-01

Although prediction of clearance using hepatocytes and liver microsomes has long played a decisive role in drug discovery, it is widely acknowledged that reliably accurate prediction is not yet achievable despite the predominance of hepatically cleared drugs. Physiologically mechanistic methodology tends to underpredict clearance by several fold, and empirical correction of this bias is confounded by imprecision across drugs. Understanding the causes of prediction uncertainty has been slow, possibly reflecting poor resolution of variables associated with donor source and experimental methods, particularly for the human situation. It has been reported that among published human hepatocyte predictions there was a tendency for underprediction to increase with increasing in vivo intrinsic clearance, suggesting an inherent limitation using this particular system. This implied an artifactual rate limitation in vitro, although preparative effects on cell stability and performance were not yet resolved from assay design limitations. Here, to resolve these issues further, we present an up-to-date and comprehensive examination of predictions from published rat as well as human studies (where n = 128 and 101 hepatocytes and n = 71 and 83 microsomes, respectively) to assess system performance more independently. We report a clear trend of increasing underprediction with increasing in vivo intrinsic clearance, which is similar both between species and between in vitro systems. Hence, prior concerns arising specifically from human in vitro systems may be unfounded and the focus of investigation in the future should be to minimize the potential in vitro assay limitations common to whole cells and subcellular fractions. Copyright © 2017 by The American Society for Pharmacology and Experimental Therapeutics.

Overlapping but distinct specificities of anti-liver-kidney microsome antibodies in autoimmune hepatitis type II and hepatitis C revealed by recombinant native CYP2D6 and novel peptide epitopes

Science.gov (United States)

Klein, R; Zanger, U M; Berg, T; Hopf, U; Berg, P A

1999-01-01

Anti-liver-kidney microsome antibodies (anti-LKM) occur in autoimmune hepatitis (AIH) type II and in a subset of patients with hepatitis C. Anti-LKM1 in AIH are directed against cytochrome P4502D6 (CYP2D6), but conflicting data exist concerning the specificity of anti-LKM in hepatitis C. The aim of this study was to evaluate binding specificities of anti-LKM antibodies in both diseases using novel test antigens as well as their inhibitory capacity on CYP2D6 enzyme activity. Sera from 22 patients with AIH type II and 17 patients with hepatitis C being anti-LKM-positive in the immunofluorescence test were investigated for binding to native recombinant CYP2D6 and liver microsomes by ELISA and immunoblotting, and to synthetic peptides covering the region 254–339 (254–273, 257–269, 270–294, 291–310, 307–324, 321–339, 373–389) as well as the novel peptide 196–218 by ELISA. Furthermore, all sera were tested for inhibition of CYP2D6-dependent bufuralol 1′-hydroxylase activity. Twenty of the 22 AIH type II sera (91%) and nine of the 17 hepatitis C sera (53%) were positive for CYP2D6 by ELISA and/or immunoblotting. The previously described major peptide epitope comprising CYP2D6 amino acids 257–269 was recognized by 16 of the 22 AIH sera but by only one hepatitis C serum. A further epitope, 196–218, could be defined for the first time as another immunodominant epitope for AIH because it was recognized by 15 of the 22 AIH (68%) but only three of the 17 hepatitis C sera (18%). With the exception of the peptide 254–273, the other peptides showed no significant reactivity. Analysing the inhibitory properties of anti-LKM antibodies it emerged that 95% of AIH sera and 88% of hepatitis C sera inhibited enzyme function. These data indicate that anti-LKM antibodies in AIH and hepatitis C react with CYP2D6, as shown by their inhibitory activity, and that besides the known epitope 257–269 a further immunodominant epitope exists on CYP2D6 which is recognized

Liver/kidney microsomal antibody type 1 and liver cytosol antibody type 1 concentrations in type 2 autoimmune hepatitis

OpenAIRE

Muratori, L; Cataleta, M; Muratori, P; Lenzi, M; Bianchi, F

1998-01-01

Background—Liver/kidney microsomal antibody type 1 (LKM1) and liver cytosol antibody type 1 (LC1) are the serological markers of type 2 autoimmune hepatitis (AIH). 
Aims—Since LKM1 and LC1 react against two distinct liver specific autoantigens (cytochrome P450IID6 (CYP2D6) and a 58 kDa cytosolic polypeptide respectively), the aim was to see whether LKM1 and LC1 concentrations correlate with liver disease activity. 
Patients—Twenty one patients with type 2 AIH were studied. 
Methods—A...

Impaired rate of microsomal fatty acid elongation in undernourished neonatal rat brain

International Nuclear Information System (INIS)

Yeh, Y.Y.

1986-01-01

Hypomyelination caused by undernourishment in characterized by low concentrations of myelin lipids and marked reduction in lignocerate (C/sub 24:0/) and nervonate (C/sub 24:1/) moiety of cerebroside and sulfatide. Since microsomal elongation is the major source of long chain (22 to 24 carbons) fatty acids in the brain, the effect of neonatal undernourishment on acyl elongation was investigated. Undernourishment of suckling rats were induced after birth by restricting maternal dietary intake to 40% of that consumed by dams fed ad libitum. Neonates suckled by the normally fed dams served as controls. Microsomal elongation was measured as nmol from [2- 14 C] malonyl CoA incorporated/h per mg of protein. At 19 days of age, rates of behenoyl CoA (C/sub 22:0/) and erucoyl CoA (C/sub 22:1/) elongation in whole brain of undernourished neonates were 30-40% lower than that of the control, whereas the elongation rates of acyl CoA 16, 18 and 20 carbons in length either saturated or monounsaturated were similar in both groups. Undernourishment had no effect on cytoplasmic de novo fatty acid synthesis from acetyl CoA. If there are multiple elongation factors, the results indicate that the depressed activity of elongating enzyme(s) for C/sub 22:0/ and C/sub 22:1/ is an important contributing factor in lowering S/sub 24:0/ and C/sub 24:1/ content in cerebroside and sulfatide. This impairment may be a specific lesion leading to hypomyelination in undernourished rats

Stereoselective in vitro metabolism of rhynchophylline and isorhynchophylline epimers of Uncaria rhynchophylla in rat liver microsomes.

Science.gov (United States)

Wang, Xin; Qiao, Zhou; Liu, Jia; Zheng, Mei; Liu, Wenyuan; Wu, Chunyong

2017-11-10

1. The objective was to investigate the underlying mechanism of the stereoselectivity in the metabolism of rhynchophylline (RIN) and isorhynchophylline (IRN) epimers in rat liver microsomes (RLM). 2. After incubation, eight metabolites of RIN (M1-5) and IRN (M6-8) reacted at A- and C-ring were identified using LC-Q-TOF/MS. Metabolic pathways included oxidation, hydroxylation, N-oxidation and dehydrogenation. In addition, hydroxylation at A-ring was the major metabolic pathway for RIN whereas the oxidation at C-ring was the major one for IRN. 3. Enzyme kinetics showed that the intrinsic clearance (CL int ) for IRN elimination was 1.9-fold higher than RIN and the degradation half-life (T 1/2 ) of RIN was 4.7-fold higher than that of IRN, indicating IRN was more favorable to be metabolized than RIN in RLM. 4. Data from chemical inhibition study demonstrated CYP3A was the predominant isoform involved in the metabolic elimination of both epimers, as well as the formation of M1-8. 5. In conclusion, data revealed that due to the spatial configurations at C-7 position, RIN and IRN epimers possessed different hepatic metabolic pathways and elimination rates which were mainly mediated by CYP3A.

Clinical features and effect of antiviral therapy on anti-liver/kidney microsomal antibody type 1 positive chronic hepatitis C.

Science.gov (United States)

Ferri, Silvia; Muratori, Luigi; Quarneti, Chiara; Muratori, Paolo; Menichella, Rita; Pappas, Georgios; Granito, Alessandro; Ballardini, Giorgio; Bianchi, Francesco B; Lenzi, Marco

2009-06-01

Anti-liver/kidney microsomal antibody type 1 (anti-LKM1), a serological marker of type 2 autoimmune hepatitis, is also detected in a small proportion of patients with hepatitis C. This study aimed to evaluate clinical features and effect of antiviral therapy in patients with hepatitis C who are anti-LKM1 positive. Sixty consecutive anti-LKM1 positive and 120 age and sex-matched anti-LKM1 negative chronic hepatitis C patients were assessed at diagnosis and during follow-up. Of these, 26 anti-LKM1 positive and 72 anti-LKM1 negative received antiviral therapy. Anti-LKM1 was detected by indirect immunofluorescence and immunoblot. Number of HCV-infected hepatocytes and intrahepatic CD8+ lymphocytes was determined by immunohistochemistry. At diagnosis anti-LKM1 positive patients had higher IgG levels and more intrahepatic CD8+ lymphocytes (p 0.022 and 0.046, respectively). Viral genotypes distribution and response to therapy were identical. Hepatic flares during antiviral treatment only occurred in a minority of patients in concomitance with anti-LKM1 positivity. Immune system activation is more pronounced in anti-LKM1 positive patients with hepatitis C, possibly representing the expression of autoimmune mechanisms of liver damage. Antiviral treatment is as beneficial in these patients as in anti-LKM1 negative patients, and the rare necroinflammatory flares are effectively controlled by corticosteroids, allowing subsequent resumption of antiviral therapy.

Hydrolysis of pyrethroids by human and rat tissues: Examination of intestinal, liver and serum carboxylesterases

International Nuclear Information System (INIS)

Crow, J. Allen; Borazjani, Abdolsamad; Potter, Philip M.; Ross, Matthew K.

2007-01-01

Hydrolytic metabolism of pyrethroid insecticides in humans is one of the major catabolic pathways that clear these compounds from the body. Rodent models are often used to determine the disposition and clearance rates of these esterified compounds. In this study the distribution and activities of esterases that catalyze pyrethroid metabolism have been investigated in vitro using several human and rat tissues, including small intestine, liver and serum. The major esterase in human intestine is carboxylesterase 2 (hCE2). We found that the pyrethroid trans-permethrin is effectively hydrolyzed by a sample of pooled human intestinal microsomes (5 individuals), while deltamethrin and bioresmethrin are not. This result correlates well with the substrate specificity of recombinant hCE2 enzyme. In contrast, a sample of pooled rat intestinal microsomes (5 animals) hydrolyze trans-permethrin 4.5-fold slower than the sample of human intestinal microsomes. Furthermore, it is demonstrated that pooled samples of cytosol from human or rat liver are ∼ 2-fold less hydrolytically active (normalized per mg protein) than the corresponding microsomal fraction toward pyrethroid substrates; however, the cytosolic fractions do have significant amounts (∼ 40%) of the total esteratic activity. Moreover, a 6-fold interindividual variation in carboxylesterase 1 protein expression in human hepatic cytosols was observed. Human serum was shown to lack pyrethroid hydrolytic activity, but rat serum has hydrolytic activity that is attributed to a single CE isozyme. We purified the serum CE enzyme to homogeneity to determine its contribution to pyrethroid metabolism in the rat. Both trans-permethrin and bioresmethrin were effectively cleaved by this serum CE, but deltamethrin, esfenvalerate, alpha-cypermethrin and cis-permethrin were slowly hydrolyzed. Lastly, two model lipase enzymes were examined for their ability to hydrolyze pyrethroids. However, no hydrolysis products could be detected

Effects of d-norgestrel on lipid metabolism in the rat

Energy Technology Data Exchange (ETDEWEB)

Khokha, R.

1985-01-01

The effects of the progestin d-norgestrel (d-Ng) on lipid and lipoprotein metabolism and elucidate its mechanism of action using the rat as the experimental model were investigated. d-Ng fed to female rats (18 days) in conventional doses, significantly lowered the plasma total and very low density lipoprotein (VLDL)-triglycerides. In contrast, the plasma total and low density lipoprotein (LDL)-cholesterol rose significantly. The triglyceride synthesis was studied using isolated rate hepatocytes. d-Ng (0.1 mM), in the presence of 0.1% dimethylsulfoxide concentration of the medium, significantly inhibited the incorporation of both (9,10-/sup 3/H) palmitate and (U-/sup 14/C) glycerol into triglycerides synthesized and triglycerides released by the hepatocytes. The inhibition of triglyceride synthesis by d-Ng was dose-dependent. Further studies of the effect of d-Ng on the rate limiting enzymes of triglyceride synthesis showed a significant reduction in the specific activity of hepatic glycerol phosphate acyltransferase (GPAT) and phosphatidic acid aqueous dependent phosphatidic acid phosphatase (PAPase) specifically in the microsomes. However, the specific activity of mitochondrial GPAT and phosphatidic acid membrane bound dependent PAPase in microsomes as well as cytosol remained unchanged. These findings suggest that d-Ng acts by inhibiting specifically the hepatic lipogenic enzymes in the microsomes. This subsequently reduces the triglyceride synthesis and secretion by the liver resulting in lower plasma and VLDL triglycerides levels in d-Ng-treated rats.

Up-regulation of hepatic Acyl CoA: Diacylglycerol acyltransferase-1 (DGAT-1) expression in nephrotic syndrome.

Science.gov (United States)

Vaziri, Nosratola D; Kim, Choong H; Phan, Dennis; Kim, Sara; Liang, Kaihui

2004-07-01

Nephrotic syndrome is associated with hypercholesterolemia, hypertriglyceridemia, and marked elevations of plasma low-density lipoprotein (LDL) and very low-density lipoprotein (VLDL). Hypertriglyceridemia in nephrotic syndrome is accompanied by increased hepatic fatty acid synthesis, elevated triglyceride secretion, as well as lipoprotein lipase, VLDL-receptor, and hepatic triglyceride lipase deficiencies, which lead to impaired clearance of triglyceride-rich lipoproteins. Acyl CoA: diacylglycerol acyltransferase (DGAT) is a microsomal enzyme that joins acyl CoA to 1, 2-diacylglycerol to form triglyceride. Two distinct DGATs (DGAT-1 and DGAT2) have recently been identified in the liver and other tissues. The present study tested the hypothesis that the reported increase in hepatic triglyceride secretion in nephrotic syndrome may be caused by up-regulation of DGAT. Male Sprague-Dawley rats were rendered nephrotic by two sequential injections of puromycin aminonucleoside (130 mg/kg on day 1 and 60 mg/kg on day 14) and studied on day 30. Placebo-treated rats served as controls. Hepatic DGAT-1 and DGAT-2 mRNA abundance and enzymatic activity were measured. The nephrotic group exhibited heavy proteinuria, hypoalbuminemia, hypercholesterolemia, hypertriglyceridemia, and marked elevation of VLDL concentration. Hepatic DGAT-1 mRNA, DGAT-1, and total DGAT activity were significantly increased, whereas DGAT-2 mRNA abundance and activity were unchanged in the nephrotic rats compared to the control animals. The functional significance of elevation of DGAT activity was illustrated by the reduction in microsomal free fatty acid concentration in the liver of nephrotic animals. Nephrotic syndrome results in up-regulation of hepatic DGAT-1 expression and activity, which can potentially contribute to the associated hypertriglyceridemia by enhancing triglyceride synthesis. Thus, it appears that both depressed catabolism and increased synthetic capacity contribute to

Modulation of serum concentrations and hepatic metabolism of 17{beta}-estradiol and testosterone by amitraz in rats

Energy Technology Data Exchange (ETDEWEB)

Chou, Chen-Ping [National Taiwan University, Institute of Toxicology, College of Medicine, Taipei (China); Taiwan Agricultural Chemicals and Toxic Substances Research Institute, Council of Agriculture, Taichung (China); Lu, Shui-Yuan [Taiwan Agricultural Chemicals and Toxic Substances Research Institute, Council of Agriculture, Taichung (China); Ueng, Tzuu-Huei [National Taiwan University, Institute of Toxicology, College of Medicine, Taipei (China)

2008-10-15

The present study has investigated the ability of amitraz, a widely used formamidine pesticide, to modulate serum concentrations and liver microsomal metabolism of 17{beta}-estradiol (E2) and testosterone in rats. Amitraz was administered intraperitoneally to male rats for 4 days and to intact female rats or ovariectomized (OVX) and 0.5 mg/kg E2-supplemented female rats for 7 days. E2 and metabolites were analyzed by gas chromatography-electron capture detection and testosterone and metabolites were analyzed by high-pressure liquid chromatography. In OVX and E2-supplemented females, 50 mg/kg amitraz caused an 85% decrease of serum E2 concentration and a marked increase of 2-OH-E2 concentration. Amitraz at 25 and 50 mg/kg produced 9.0-fold or greater increases of serum testosterone and 2{beta}-OH-testosterone levels in males. Amitraz at 25 mg/kg resulted in no or minimal increases of liver microsomal formation of E2 or testosterone metabolites. Amitraz at 50 mg/kg produced 1.4- to 3.6-fold increases of 2-OH-E2; estrone; 2{beta}-, 6{beta}-, and 16{alpha}-OH-testosterone; and androstenedione formation in males and intact females. Amitraz at 50 mg/kg preferentially increased intact female 16{beta}-OH-testosterone production by 8.6-fold. In OVX females, E2 supplement alone or cotreatment with E2 and 50 mg/kg amitraz produced 1.3- to several-fold increases of 2- and 4-OH-E2 formation and 2{beta}- and 16{alpha}-OH-testosterone production. The cotreatment increased 6{beta}- and 16{beta}-OH-testosterone formation by 1.8- and 1.6-fold, respectively. The present findings show that amitraz induces hepatic E2 and testosterone metabolism in male and female rats, decreases serum E2 concentration in OVX and E2-supplemented females, but increases serum testosterone in males. (orig.)

Biotransformation, distribution and toxicity of carbon disulfide in immature rats

International Nuclear Information System (INIS)

Green, E.C.

1984-01-01

The 24-hour LD-50 values of CS 2 in 1-, 5-, 10-, 20-, 30-, and 40-day-old rats were 583, 974, 1119, 1545, 1237, and 1183 mg/kg, respectively. Twenty-four hours after CS 2 exposure, decreases in aniline hydroxylation and cytochrome P-450 were observed in rats older than one day of age. Hepatic microsomes from rats of all ages biotransformed CS 2 to COS in vitro in the presence of NADPH. Inhibition of the hepatic mixed-function oxidase enzyme system (HMFOES) was observed after incubation of hepatic microsomes from rats as young as one day of age with CS 2 and NADPH. Studies with radiolabelled CS 2 showed that a covalently binding sulfur metabolite, free from the carbon atom of CS 2 , was formed in vitro during the metabolism of CS 2 to COS which appeared to be responsible for the inhibition of the HMFOES. Three hours after 14 C-CS 2 administration in vivo to rats, between 58 and 83% of the dose of 14 C-CS 2 was expired; 4-9% of the dose was expired as 14 C-CO 2 depending on age. One to 2% of the dose of 14 C-CS 2 , and 1 to 6% of the dose of 35 S-CS 2 remained as biotransformation products in tissues. Biotransformation products of CS 2 were identified as either acid-labile or covalently bound. The results of the study implicated CS 2 biotransformation to sulfur metabolites as an important mechanism of CS 2 toxicity, particularly to 1-day-old rats which had the lowest capacity to eliminate these metabolites

Effect of cholesterol feeding on tissue lipid perioxidation, glutathione peroxidase activity and liver microsomal functions in rats and guinea pigs

NARCIS (Netherlands)

TSAI, A. C.; THIE, G. M.; Lin, C. R.

1977-01-01

The effect of cholesterol feeding on liver and aortic nonenzymatic lipid peroxidation and glutathione peroxidase activities, and on liver microsomal NADPH-dependent lipid peroxidation, codeine hydroxylation and cytochrome P-450 levels was examined in rats and guinea pigs. One percent cholesterol was

Carbon tetrachloride treatment induces anorexia independently of hepatitis in rats.

Science.gov (United States)

Okamoto, T; Okabe, S

2000-08-01

Oxidative stress is involved in the development of anorexia. In the present study, we examined the possible involvement of anorexia in oxygen radical-induced hepatitis. A low dose of carbon tetrachloride (1 ml/kg of a 1:1 solution with olive oil) was orally administered to rats with and without food restriction. In rats with food restriction, carbon tetrachloride treatment induced hepatitis and reduced the body weight gain. In contrast, carbon tetrachloride treatment did not induce hepatitis in rats without food restriction, but the body weight was decreased. In these rats, the loss of body weight was accompanied by a decrease in food intake. The present results indicate that the administration of a low dose of carbon tetrachloride to rats without food restriction induced anorexia independently of hepatitis.

Disruption of thyroid hormone homeostasis in Ugt1a-deficient Gunn rats by microsomal enzyme inducers is not due to enhanced thyroxine glucuronidation

International Nuclear Information System (INIS)

Richardson, Terrilyn A.; Klaassen, Curtis D.

2010-01-01

Microsomal enzyme inducers (MEI) that increase UDP-glucuronosyltransferases (UGTs) are thought to increase glucuronidation of thyroxine (T 4 ), thus reducing serum T 4 , and subsequently increasing thyroid stimulating hormone (TSH). Ugt1a1 and Ugt1a6 mediate T 4 glucuronidation. Therefore, this experiment determined the involvement of Ugt1a enzymes in increased T 4 glucuronidation, decreased serum T 4 , and increased TSH after MEI treatment. Male Wistar and Ugt1a-deficient Wistar (Gunn) rats were fed a control diet or diet containing pregnenolone-16α-carbonitrile (PCN; 800 ppm), 3-methylcholanthrene (3-MC; 200 ppm), or Aroclor 1254 (PCB; 100 ppm) for 7 days. Serum T 4 , triiodothyronine (T 3 ), and TSH concentrations, hepatic T 4 /T 3 glucuronidation, and thyroid histology and follicular cell proliferation were investigated. PCN, 3-MC, and PCB treatments decreased serum T 4 , whereas serum T 3 was maintained in both Gunn and Wistar rats (except for PCB treatment). TSH was increased in Wistar and Gunn rats after PCN (130 and 277%) or PCB treatment (72 and 60%). T 4 glucuronidation in Wistar rats was increased after PCN (298%), 3-MC (85%), and PCB (450%), but was extremely low in Gunn rats, and unchanged after MEI. T 3 glucuronidation was increased after PCN (121%) or PCB (58%) in Wistar rats, but only PCN increased T 3 glucuronidation in Gunn rats (43%). PCN treatment induced thyroid morphological changes and increased follicular cell proliferation in both strains. These data demonstrate that T 4 glucuronidation cannot be increased in Ugt1a-deficient Gunn rats. Thus, the decrease in serum T 4 , increase in TSH, and increase in thyroid cell proliferation after MEI are not dependent on increased T 4 glucuronidation, and cannot be attributed to Ugt1a enzymes.

Effect of Ganfukang on liver function and serum hepatic fibrosis markers levels in SD rats with experimental hepatic fibrosis

International Nuclear Information System (INIS)

Che Ying; Wang Shanju; Xu Tingting; Jiang Miaona; Jia Yujie

2004-01-01

Objective: To observe the effect of Ganfukang on liver function and serum hepatic fibrosis markers levels in SD rats with experimental hepatic fibrosis. Methods: SD rat models of liver fibrosis was induced by CCl 4 (n=57). Liver function (GPT, GOT) and serum hepatic fibrosis markers levels (HA, LN, C-IV, PC-III, with RIA) were tested in these models and 10 control rats. Eleven model rats were left untreated, the others were treated with Ganfukang of different concentrations and the above hepatic parameters were again determined after completion of treatment. Results: Lever function was much deteriorated and serum markers levels significantly increased in the model rats (vs controls, P<0.01). After treatment with Ganfukang, the improvement was significant (vs untreated models, P<0.01). Conclusion: Ganfukang is of definite therapeutic value for experimental hepatic fibrosis in rat models. (authors)

Liver/kidney microsomal antibody type 1 targets CYP2D6 on hepatocyte plasma membrane

Science.gov (United States)

Muratori, L; Parola, M; Ripalti, A; Robino, G; Muratori, P; Bellomo, G; Carini, R; Lenzi, M; Landini, M; Albano, E; Bianchi, F

2000-01-01

BACKGROUND—Liver/kidney microsomal antibody type 1 (LKM1) is the marker of type 2 autoimmune hepatitis (AIH) and is detected in up to 6% of patients with hepatitis C virus (HCV) infection. It recognises linear and conformational epitopes of cytochrome P450IID6 (CYP2D6) and may have liver damaging activity, provided that CYP2D6 is accessible to effector mechanisms of autoimmune attack.
METHODS—The presence of LKM1 in the plasma membrane was investigated by indirect immunofluorescence and confocal laser microscopy of isolated rat hepatocytes probed with 10 LKM1 positive sera (five from patients with AIH and five from patients with chronic HCV infection) and a rabbit polyclonal anti-CYP2D6 serum.
RESULTS—Serum from both types of patient stained the plasma membrane of non-permeabilised cells, where the fluorescent signal could be visualised as discrete clumps. Conversely, permeabilised hepatocytes showed diffuse submembranous/cytoplasmic staining. Adsorption with recombinant CYP2D6 substantially reduced plasma membrane staining and LKM1 immunoblot reactivity. Plasma membrane staining of LKM1 colocalised with that of anti-CYP2D6. Immunoprecipitation experiments showed that a single 50 kDa protein recognised by anti-CYP2D6 can be isolated from the plasma membrane of intact hepatocytes.
CONCLUSIONS—AIH and HCV related LKM1 recognise CYP2D6 exposed on the plasma membrane of isolated hepatocytes. This observation supports the notion that anti-CYP2D6 autoreactivity may be involved in the pathogenesis of liver damage.


Keywords: liver/kidney microsomal antibody type 1; autoimmunity; autoimmune hepatitis; hepatitis C virus infection; confocal microscopy PMID:10716687

Effect of thiabendazole on some rat hepatic xenobiotic metabolising enzymes

NARCIS (Netherlands)

Price, R.J.; Scott, M.P.; Walters, D.G.; Stierum, R.H.; Groten, J.P.; Meredith, C.; Lake, B.G.

2004-01-01

The effect of thiabendazole (TB) on some rat hepatic xenobiotic metabolising enzymes has been investigated. Male Sprague-Dawley rats were fed control diet or diets containing 102-5188 ppm TB for 28 days. As a positive control for induction of hepatic xenobiotic metabolism, rats were also fed diets

Ontogeny of the rat hepatic adrenoceptors

International Nuclear Information System (INIS)

McMillian, M.K.

1985-01-01

Hepatic alpha-1, alpha-2, and beta-2 adrenoceptors were characterized during development of the rat through Scatchard analysis of ( 3 H)-prazosin, ( 3 H)-rauwolscine and ( 125 I)-pindolol binding to washed particle membrane preparations. Major changes in adrenoceptor number occur shortly before birth and at weaning. The fetal rat liver is characterized by a large number of alpha-2 adrenoceptors which falls 10-20 fold at birth. The number of hepatic beta adrenoceptors decreases 30-50% during the third week after birth increases slightly at weaning, then decreases gradually in the adult. Hepatic alpha-1 adrenoceptor number increases 3-5 fold at weaning to become the predominant adrenoceptor in the adult rat liver. The basis for the fall in alpha-2 number at birth remains unclear. The fall in beta receptor number at the end of the second week post-natally appears dependent on increased insulin and corticosterone secretion as well as increased NE release form nerve terminals. The basis for the increase in beta number at weaning and the sex-dependent loss of beta function but not receptor number in the adult rat remains unknown. The dramatic increases in alpha-1 number and function at weaning are dependent on increased adrenocortical secretion, adrenalectomy prevents the normal. This effect of adrenocorticoids might be mediated through glycogen, as glycogen depletion during fasting decreases alpha-1 receptor number and function at weaning are dependent on increased adrenocortical secretion, adrenalectomy prevents the normal. This effect of adrenocorticoids might be mediated through glycogen, as glycogen depletion during fasting decreases alpha-1 receptor number and function. These findings suggest that hepatic adrenoceptor number adapts from the low carbohydrate diet of the suckling rat to the high carbohydrate diet of the adult at weaning

Biotransformation of a novel antimitotic agent, I-387, by mouse, rat, dog, monkey, and human liver microsomes and in vivo pharmacokinetics in mice.

Science.gov (United States)

Ahn, Sunjoo; Kearbey, Jeffrey D; Li, Chien-Ming; Duke, Charles B; Miller, Duane D; Dalton, James T

2011-04-01

3-(1H-Indol-2-yl)phenyl)(3,4,5-trimethoxyphenyl)methanone (I-387) is a novel indole compound with antitubulin action and potent antitumor activity in various preclinical models. I-387 avoids drug resistance mediated by P-glycoprotein and showed less neurotoxicity than vinca alkaloids during in vivo studies. We examined the pharmacokinetics and metabolism of I-387 in mice as a component of our preclinical development of this compound and continued interest in structure-activity relationships for antitubulin agents. After a 1 mg/kg intravenous dose, noncompartmental pharmacokinetic analysis in plasma showed that clearance (CL), volume of distribution at steady state (Vd(ss)), and terminal half-life (t(1/2)) of I-387 were 27 ml per min/kg, 5.3 l/kg, and 7 h, respectively. In the in vitro metabolic stability study, half-lives of I-387 were between 10 and 54 min by mouse, rat, dog, monkey, and human liver microsomes in the presence of NADPH, demonstrating interspecies variability. I-387 was most stable in rat liver microsomes and degraded quickly in monkey liver microsomes. Liquid chromatography-tandem mass spectrometry was used to identify phase I metabolites. Hydroxylation, reduction of a ketone group, and O-demethylation were the major metabolites formed by the liver microsomes of the five species. The carbonyl group of I-387 was reduced and identified as the most labile site in human liver microsomes. The results of these drug metabolism and pharmacokinetic studies provide the foundation for future structural modification of this pharmacophore to improve stability of drugs with potent anticancer effects in cancer patients.

Distribution of sterol carrier protein2 (SCP2) in rat tissues and evidence for slow turnover in liver and adrenal cortex

International Nuclear Information System (INIS)

Kharroubi, A.; Chanderbhan, R.; Fiskum, G.; Noland, B.J.; Scallen, T.J.; Vahouny, G.V.

1986-01-01

Sterol carrier protein 2 (SCP 2 ) has been implicated in the regulation of the terminal stages of hepatic cholesterol biosynthesis, and in sterol utilization for adrenal steroid hormone and hepatic bile acid synthesis. In the present studies, a highly sensitive radioimmunoassay, using [ 125 I] SCP 2 , has been developed. Highest levels of SCP 2 were found in rat liver with progressively lower levels in intestinal mucosa, adrenal, kidney, lung and testis. SCP 2 levels were low or absent in heart, brain, skeletal muscle and serum. Liver SCP 2 was largely (44%) associated with the microsomal fraction, while in adrenal, 46% was associated with mitochondria, a distribution which is consistent with the proposed roles for SCP 2 in these tissues. Levels of SCP 2 in AS 30D hepatoma cells were only 5% of those in normal liver. In liver there was no indication of diurnal rhythm of SCP 2 in the cytosol and only slight variation of the microsomal SCP 2 levels. Fasting has only slight effects on SCP 2 concentration of rat liver microsomes and cytosol. Neither ACTH nor cycloheximide treatment of rats had a significant effect on SCP 2 distribution in the adrenal. In general, these findings indicate that SCP 2 has a low turn-over rate

Evaluation of the synergistic effect of Allium sativum, Eugenia jambolana, Momordica charantia, Ocimum sanctum and Psidium guajav on hepatic and intestinal drug metabolizing enzymes in rats

Directory of Open Access Journals (Sweden)

Devendra Kumar

2016-12-01

Full Text Available Aims/Background: Present study investigated the synergistic effect of polyherbal formulations (PHF of Allium sativum L Eugenia jambolana Lam., Momordica charantia L., Ocimum sanctum Linn and Psidium guajava L. in the inhibition/induction of hepatic and intestinal CYPs and Phase-II conjugated drug metabolizing enzymes. Consumption of these herbal remedy has been extensively documented for diabetes treatment in Auyureda. Methodology: PHF of these five herbs was prepared and different doses were orally administered to Sprague Dawley rats of different groups except control group. Expression of mRNA and activity of drug metabolizing enzymes were examined by RT-PCR and HPLC in isolated liver and intestine microsomes in PHF pretreated rats. Results: Activities of hepatic and intestinal Phase-II enzyme levels increased along with mRNA levels except CYP3A mRNA level. PHF administration increases the activity of hepatic and intestinal UDPGT and GST in response to dose and time; however, activity of hepatic SULT increased at higher doses. Conclusions: CYPs and Phase-II conjugated enzymes levels can be modulated in dose and time dependent manner. Observations suggest that poly herbal formulation might be a possible cause of herb-drug interaction, due to changes in pharmacokinetic of crucial CYPs and Phase-II substrate drug. [J Complement Med Res 2016; 5(4.000: 372-382

The effects of estrus cycle on drug metabolism in the rat.

Science.gov (United States)

Brandstetter, Y; Kaplanski, J; Leibson, V; Ben-Zvi, Z

1986-01-01

The effect of the female rat estral cycle on microsomal drug metabolism in-vivo and in-vitro has been studied. Two microsomal enzymes, aminopyrine-N-demethylase and aniline hydroxylase showed a greater specific activity (p less than 0.01) in the diestrus phase of the estral cycle while the oxidative enzyme aryl hydrocarbon hydroxylase and the conjugative enzyme, glucuronyl transferase, were not affected. In vivo studies which included theophylline and antipyrine metabolism, and hexobarbital sleeping times showed no difference between the different phases of the estral cycle. Conflicting evidence about the effect of steroid sex hormones on hepatic drug metabolism is discussed.

Systemic excretion of benzo(a)pyrene in the control and microsomally induced rat: the influence of plasma lipoproteins and albumin as carrier molecules

International Nuclear Information System (INIS)

Shu, H.P.; Bymun, E.N.

1983-01-01

In vitro studies have previously indicated that benzo(a)pyrene distributes primarily into the plasma lipoprotein fraction when incubated with whole plasma. Hydroxylated metabolites of benzo(a)pyrene distribute increasingly into the albumin fraction as the degree of metabolite hydroxylation increases. This report assesses the influence of plasma lipoproteins and albumin as carriers for benzo(a)pyrene on carcinogen excretion in the control and microsomally induced rat. Male Sprague-Dawley rats cannulated in the bile duct received i.v. injections of radiolabeled benzo(a)pyrene noncovalently bound to the very-low-density, low-density, or high-density lipoproteins in equimolar amounts. Bile was collected and measured for radioactivity. Cumulative biliary excretions of benzo(a)pyrene complexed with rat lipoproteins were 39.6 +/- 9.7 (S.D.), 24.6 +/- 1.3, and 21.2 +/- 8.8% for very low-density, low-density, and high-density lipoprotein, respectively. Values for excretion of benzo(a)pyrene complexed with rat or human lipoproteins were comparable. These data suggest that the transport molecule can effect a 2-fold difference in benzo(a)pyrene excretion under conditions of the present study. Thus, excretion increased as the degree of benzo(a)pyrene hydroxylation increased. The effect of microsomal enzyme induction on excretion of lipoprotein-bound benzo(a)pyrene was also assessed. Contrary to expectation, excretion of benzo(a)pyrene bound to the very-low-density, low-density, or high-density lipoproteins in Aroclor-induced rats was not greater than that of control animals. Hence, under the conditions of the present study, 60 to 80% of the injected benzo(a)pyrene and 50 to 60% of the injected benzo(a)pyrene metabolites were not excreted immediately in control or microsomally induced animals. This benzo(a)pyrene may represent a carcinogen pool that is slowly excreted

Liver cytosolic 1 antigen-antibody system in type 2 autoimmune hepatitis and hepatitis C virus infection.

Science.gov (United States)

Lenzi, M; Manotti, P; Muratori, L; Cataleta, M; Ballardini, G; Cassani, F; Bianchi, F B

1995-01-01

Within the multiform liver/kidney microsomal (LKM) family, a subgroup of sera that reacts with a liver cytosolic (LC) protein has been isolated and the new antigen-antibody system is called LC1. Unlike LKM antibody type 1 (anti-LKM1), anti-LC1 is said to be unrelated to hepatitis C virus (HCV) infection and has therefore been proposed as a marker of 'true' autoimmune hepatitis type 2. Altogether 100 LKM1 positive sera were tested by immunodiffusion (ID). Twenty five gave a precipitation line with human liver cytosol; 17 of the 25 also reacted with rat liver cytosol. Thirteen of the 25 sera were anti-HCV positive by second generation ELISA: anti-HCV positive patients were significantly older (p LKM1, and that it is an additional marker of juvenile autoimmune hepatitis type 2. It does not, however, discriminate between patients with and without HCV infection. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:7797126

Influence of sex hormones on relative quantities of multiple species of cytochrome P-450 in rat liver microsomes

International Nuclear Information System (INIS)

Fujita, S.; Peisach, J.; Chevion, M.; Hebrew Univ., Jerusalem

1981-01-01

EPR spectra of rat liver microsomes from male, female and hormonally-treated castrated hepatectomized rats were studied. The spectra, especially in the region of gsub(max) suggested a heterogeneity of local environments of the low spin ferric heme indicative of multiple structures for cytochrome P-450. Certain features in the spectrum correlated with sexual differences. It is suggested that the changes in the relative amplitudes of the EPR features represent differences in the relative abundance of the individual proteins in the mixture that, in turn, are related to the sexual differences of metabolic patterns for reactions catalyzed by cytochrome P-450. (author)

The Cytochrome P450-Mediated Metabolism Alternation of Four Effective Lignans From Schisandra chinensis in Carbon Tetrachloride-Intoxicated Rats and Patients With Advanced Hepatocellular Carcinoma.

Science.gov (United States)

Wu, Rongrong; Xiao, Zhiyong; Zhang, Xiaorui; Liu, Feng; Zhou, Wenxia; Zhang, Yongxiang

2018-01-01

It is highly valuable to study the pharmacokinetics of herbal components under the pathological condition of liver dysfunction for safe and rational use of herbal medicines. In this study, the pharmacokinetic profiles of four effective lignans from Schisandra chinensis (SC) , schisandrin, schisantherin A, deoxyshisandrin and γ-schisandrin, were investigated in carbon tetrachloride (CCl 4 )-intoxicated rats. The metabolism of the four lignans was also studied using microsomes from patients with advanced hepatocellular carcinoma. In situ intestinal and hepatic perfusions were conducted to clarify the contributions from impairments of gut and liver on the pharmacokinetics of the four schisandra lignans in CCl 4 -intoxicated rats. The metabolism in rat and human liver microsomes and transport in Caco-2 monolayer cell model were studied to reveal the key factors for the in vivo disposition of the four lignans. When SC alcoholic extract was orally administrated to CCl 4 -intoxicated rat for a short term (4 days), the pharmacokinetics of four active SC lignans was significantly changed while its hepatotherapeutic effect was not obviously observed. The plasma concentrations of the four schisandra lignans were dramatically elevated compared with the control. The Cmax, AUC and MRT were all increased or prolonged significantly while parameter CLz/F was obviously reduced in rat pretreated with CCl 4 . In hepatic perfusion study and liver microsomes incubation, it was found that the hepatic metabolism of the four lignans was markedly decreased mainly due to the activity reduction of multiple CYP450 isoenzymes involved the metabolism, which, eventually, might lead to the alternation of their pharmacokinetic profiles in CCl 4 -intoxicated rats or patients with advanced hepatocellular carcinoma. The pharmacokinetic studies of SC components in pathological situation of liver dysfunction are expected to provide useful data for rational and safe application of SC preparations in

Role of UDP-Glucuronosyltransferase (UGT) 2B2 in Metabolism of Triiodothyronine: Effect of Microsomal Enzyme Inducers in Sprague Dawley and UGT2B2-Deficient Fischer 344 Rats

Science.gov (United States)

Richardson, Terrilyn A.; Klaassen, Curtis D.

2010-01-01

Microsomal enzyme inducers (MEI) that increase UDP-glucuronosyltransferases (UGTs) can impact thyroid hormone homeostasis in rodents. Increased glucuronidation can result in reduction of serum thyroid hormone and a concomitant increase in thyroid-stimulating hormone (TSH). UGT2B2 is thought to glucuronidate triiodothyronine (T3). The purposes of this study were to determine the role of UGT2B2 in T3 glucuronidation and whether increased T3 glucuronidation mediates the increased TSH observed after MEI treatment. Sprague Dawley (SD) and UGT2B2-deficient Fischer 344 (F344) rats were fed a control diet or diet containing pregnenolone-16α-carbonitrile (PCN; 800 ppm), 3-methylcholanthrene (3-MC; 200 ppm), or Aroclor 1254 (PCB; 100 ppm) for 7 days. Serum thyroxine (T4), T3, and TSH concentrations, hepatic androsterone/T4/T3 glucuronidation, and thyroid follicular cell proliferation were determined. In both SD and F344 rats, MEI treatments decreased serum T4, whereas serum T3 was maintained (except with PCB treatment). Hepatic T4 glucuronidation increased significantly after MEI in both rat strains. Compared with the other MEI, only PCN treatment significantly increased T3 glucuronidation (281 and 497%) in both SD and UGT2B2-deficient F344 rats, respectively, and increased both serum TSH and thyroid follicular cell proliferation. These data demonstrate an association among increases in T3 glucuronidation, TSH, and follicular cell proliferation after PCN treatment, suggesting that T3 is glucuronidated by other PCN-inducible UGTs in addition to UGT2B2. These data also suggest that PCN (rather than 3-MC or PCB) promotes thyroid tumors through excessive TSH stimulation of the thyroid gland. PMID:20421340

Preparation of rat gastric heavy and light microsomal membranes enriched in (H+-K+)-ATPase using 2H2O and Percoll gradients

International Nuclear Information System (INIS)

Im, W.B.; Davis, J.P.; Blakeman, D.P.

1985-01-01

Gastric heavy microsomal membranes highly enriched in (H + -K + )-ATPase were obtained from cimetidine- or carbachol-treated rats through 2 H 2 O and Percoll gradient centrifugations. Both the resting (cimetidine-treated) and the stimulated (carbachol-treated) heavy membranes which presumably represent the apical membrane of gastric parietal cells were enriched with the polypeptides of 81,000 and 45,000 besides that of 93,000 representing (H + -K + )-ATPase. No apparent differences could be detected between the resting and the stimulated heavy membranes in their polypeptide profiles or their specific activity of (H + -K + )-ATPase. Nevertheless, the level of 86 RbCl uptake was greater in the stimulated than the resting heavy microsomal membrane vesicles. The light gastric microsomes which abound in intracellular tubulovesicles containing reserve (H + -K + )-ATPase as isolated from cimetidine-treated rats were similarly purified with respect to (H + -K + )-ATPase. The purified light gastric membranes were largely devoid of the polypeptides of 81,000 and 45,000 found in the heavy gastric membranes. These observations further support the current hypothesis that secretagogues bring about changes in the environment of (H + -K + )-ATPase and induce KCl permeability in the apical membrane of the parietal cells, although at present the authors have been unable to identify the polypeptide(s) responsible for the KCl pathway

Effect of iron, taurine and arginine on rat hepatic fibrosis

International Nuclear Information System (INIS)

Song Liangwen; Wang Dewen; Cui Xuemei

1997-01-01

Objective: The promotion role of iron on pathogenesis of hepatic fibrosis and the protective role of taurine and L-arginine against hepatic fibrosis were studied. Method: The model of rat radiation hepatic fibrosis was used. Experimental rats were divided into 0 Gy, 30 Gy, 30 Gy + iron, 30 Gy + taurine and 30 Gy + L-arginine groups. Serum iron, liver tissue hydroxyproline (Hyp) and malondialdehyde (MDA) were measured one and three months respectively after irradiation of hepatic tissue, production and distribution characteristics of hepatic tissue type I and III collagen were observed with a polarizing microscope. Results: Administration of iron agent could significantly increase hepatic tissue MDA content and serum iron concentration, one month after irradiation, hepatic tissue Hyp in 30 Gy + iron group began to increase, and collagen in hepatic tissue obviously increased. Taurine and L-arginine could reduce serum iron concentration and decrease production of hepatic fissure Hyp. Conclusion: Exogenous iron agent could promote early development of radiation hepatic fibrosis; taurine and arginine could diminish pathologic alteration of hepatic fibrosis to a certain extent

SUPRESSION OF MICROSOMAL OXIDATION WEAKENS HISTOCHROME’S DIURETIC EFFECT AT RATS

Directory of Open Access Journals (Sweden)

O. S. Talalaeva

2013-01-01

Full Text Available Histochrome is the medicinal form of echinochrome (2, 3, 5, 6, 8-pentahydroxy-7-ethyl-1,4-naphthoquinone. Arisen during clinical application of the drug questions concerning its biotransformation have predetermined the aim of this research: to study participation liver monooxygenase system in maintenance of histochrome’s pharmacological activity.Simple and informative method of the lifetime control of liver monooxygenase systems influence on a metabolism of a medical product is the estimation of changes of pharmacological effect of a r esearched preparation on a background microsomal oxidations i nhibitor. In experiments on rats chloramphenicol action on diuretic effect of histochrome, as the most convenient for screening, was i nvestigated.To control group of animals during 10 days were hypodermically entered by histochrome in a doze of 10 mg/kg (n = 15. Experimental animals preliminary oral received 50 mg/kg of chloramphenicol before three hours of histochrome introduction (n = 16. In both groups of animals measured volume daily excretion of water, creathinin, sodium and potassium ions excretions in experimental rats each two days. The initial level of parameters of excretory kidneys functions were estimated before introduction of preparations at animals.Long-term histochrome’s injection was followed by a fivefold increasing of water excretion and simultaneously creathinin growth one. Allocation of ions of sodium was statistically significantly increased by 11-th day of experiment, and potassium ions – since the ninth day of histochrome injection. In conditions preliminary chloramphenicol applications volume daily daily urine output and creathinin excretion were essentially less control parameters. Allocation with urine of ions of sodium was decreased almost twice in comparison with the values, fixed at introduction histochrome. Excretion potassium ions ware corresponded to an initial level during all period of supervision.Taking into

Microsomal lipid peroxidation as a mechanism of cellular damage. [Dissertation

Energy Technology Data Exchange (ETDEWEB)

Kornbrust, D.J.

1979-01-01

The NADPH/iron-dependent peroxidation of lipids in rat liver microsomes was found to be dependent on the presence of free ferrous ion and maintains iron in the reduced Fe/sup 2 +/ state. Chelation of iron by EDTA inhibited peroxidation. Addition of iron, after preincubation of microsomes in the absence of iron, did not enhance the rate of peroxidation suggesting that iron acts by initiating peroxidative decomposition of membrane lipids rather than by catalyzing the breakdown of pre-formed hydroperoxides. Liposomes also underwent peroxidation in the presence of ferrous iron at a rate comparable to intact microsomes and was stimulated by ascorbate. Carbon tetrachloride initiated lipid peroxidation in the absence of free metal ions. Rates of in vitro lipid peroxidation of microsomes and homogenates were found to vary widely between different tissues and species. The effects of paraquat on lipid peroxidation was also studied. (DC)

Hepatitis B spliced protein (HBSP) promotes the carcinogenic effects of benzo [alpha] pyrene by interacting with microsomal epoxide hydrolase and enhancing its hydrolysis activity

International Nuclear Information System (INIS)

Chen, Jin-Yan; Chen, Wan-Nan; Jiao, Bo-Yan; Lin, Wan-Song; Wu, Yun-Li; Liu, Ling-Ling; Lin, Xu

2014-01-01

The risk of hepatocellular carcinoma (HCC) increases in chronic hepatitis B surface antigen (HBsAg) carriers who often have concomitant increase in the levels of benzo[alpha]pyrene-7,8-diol-9,10-epoxide(±) (BPDE)-DNA adduct in liver tissues, suggesting a possible co-carcinogenesis of Hepatitis B virus (HBV) and benzo[alpha]pyrene in HCC; however the exact mechanisms involved are unclear. The interaction between hepatitis B spliced protein (HBSP) and microsomal epoxide hydrolase (mEH) was confirmed using GST pull-down, co-immunoprecipitation and mammalian two-hybrid assay; the effects of HBSP on mEH-mediated B[alpha]P metabolism was examined by high performance liquid chromatography (HPLC); and the influences of HBSP on B[alpha]P carcinogenicity were evaluated by bromodeoxyuridine cell proliferation, anchorage-independent growth and tumor xenograft. HBSP could interact with mEH in vitro and in vivo, and this interaction was mediated by the N terminal 47 amino acid residues of HBSP. HBSP could greatly enhance the hydrolysis activity of mEH in cell-free mouse liver microsomes, thus accelerating the metabolism of benzo[alpha]pyrene to produce more ultimate carcinnogen, BPDE, and this effect of HBSP requires the intact HBSP molecule. Expression of HBSP significantly increased the formation of BPDE-DNA adduct in benzo[alpha]pyrene-treated Huh-7 hepatoma cells, and this enhancement was blocked by knockdown of mEH. HBSP could enhance the cell proliferation, accelerate the G1/S transition, and promote cell transformation and tumorigenesis of B[alpha]P-treated Huh-7 hepatoma cells. Our results demonstrated that HBSP could promote carcinogenic effects of B[alpha]P by interacting with mEH and enhancing its hydrolysis activity

Differences in hepatic microsomal cytochrome P-450 isoenzyme induction by pyrazole, chronic ethanol, 3-methylcholanthrene, and phenobarbital in high alcohol sensitivity (HAS) and low alcohol sensitivity (LAS) rats.

Science.gov (United States)

Lucas, D; Ménez, J F; Berthou, F; Cauvin, J M; Deitrich, R A

1992-10-01

High and low alcohol sensitivity (HAS and LAS) rats have been selected for their differences in ethanol-induced sleep time. Liver monooxygenase activities were studied in HAS and LAS rats before and after treatments with known inducers such as chronic ethanol, pyrazole, 3-methylcholanthrene (3-MC) and phenobarbital (PB) to determine whether the selection procedure also selected for differences in the cytochrome P-450 (P-450) inducibility. This previously has been shown with long sleep (LS) and short sleep (SS) mice, which were selected using a similar criterion. 3-MC and PB, in conjunction with chronic ethanol treatment, were used in order to evaluate the interactions of ethanol with these inducers. Prior to treatment, total P-450 content was slightly lower in LAS than in HAS rats. However, both lines displayed the same microsomal monooxygenase activities related to different P-450 isozymes. This was demonstrated by ethoxyresorufin deethylation (EROD) for cytochrome P-450 1A1 (CYP1A1), acetanilide hydroxylation (ACET) for CYP1A2, pentoxyresorufin dealkylation (PROD) for CYP2B, 1-butanol oxidation (BUTAN) and N-nitrosodimethylamine demethylation (NDMA) for CYP2E1. After the different treatments, HAS rats did not differ from LAS rats in their CYP2E1 inducibility. However, pyrazole, PB and 3-MC treatment led to differences in CYP1A and CYP2B monooxygenase activities between the two lines. The enhancement of PROD by pyrazole treatment was less prominent in LAS (1.7-fold of the control value) than in HAS rats (3.8-fold).(ABSTRACT TRUNCATED AT 250 WORDS)

Sex-related differences in cadmium-induced alteration of drug action in the rat

Energy Technology Data Exchange (ETDEWEB)

Schnell, R.C.; Pence, D.H.; Prosser, T.D.; Miya, T.S.

1976-01-01

Three days after pretreatment of rats of both sexes with cadmium (2 mg/kg, i.p.), the duration of hypnosis induced by hexobarbital (75 mg/kg, i.p.) was potentiated in males but not females. Likewise, similar treatment with cadmium leads to significant inhibition of the metabolism of hexobarbital by hepatic microsomal enzymes obtained from male but not female animals. These data suggest that there is a sex-related difference in the ability of cadmium to alter drug action in rats.

Mode of action analysis for the synthetic pyrethroid metofluthrin-induced rat liver tumors: evidence for hepatic CYP2B induction and hepatocyte proliferation.

Science.gov (United States)

Deguchi, Yoshihito; Yamada, Tomoya; Hirose, Yukihiro; Nagahori, Hirohisa; Kushida, Masahiko; Sumida, Kayo; Sukata, Tokuo; Tomigahara, Yoshitaka; Nishioka, Kazuhiko; Uwagawa, Satoshi; Kawamura, Satoshi; Okuno, Yasuyoshi

2009-03-01

Two-year treatment with high doses of Metofluthrin produced hepatocellular tumors in both sexes of Wistar rats. To understand the mode of action (MOA) by which the tumors are produced, a series of studies examined the effects of Metofluthrin on hepatic microsomal cytochrome P450 (CYP) content, hepatocellular proliferation, hepatic gap junctional intercellular communication (GJIC), oxidative stress and apoptosis was conducted after one or two weeks of treatment. The global gene expression profile indicated that most genes with upregulated expression with Metofluthrin were metabolic enzymes that were also upregulated with phenobarbital. Metofluthrin induced CYP2B and increased liver weights associated with centrilobular hepatocyte hypertrophy (increased smooth endoplasmic reticulum [SER]), and induction of increased hepatocellular DNA replication. CYP2B1 mRNA induction by Metofluthrin was not observed in CAR knockdown rat hepatocytes using the RNA interference technique, demonstrating that Metofluthrin induces CYP2B1 through CAR activation. Metofluthrin also suppressed hepatic GJIC and induced oxidative stress and increased antioxidant enzymes, but showed no alteration in apoptosis. The above parameters related to the key events in Metofluthrin-induced liver tumors were observed at or below tumorigenic dose levels. All of these effects were reversible upon cessation of treatment. Metofluthrin did not cause cytotoxicity or peroxisome proliferation. Thus, it is highly likely that the MOA for Metofluthrin-induced liver tumors in rats is through CYP induction and increased hepatocyte proliferation, similar to that seen for phenobarbital. Based on analysis with the International Life Sciences Institute/Risk Science Institute MOA framework, it is reasonable to conclude that Metofluthrin will not have any hepatocarcinogenic activity in humans, at least at expected levels of exposure.

Antibody to liver cytosol (anti-LC1) in patients with autoimmune chronic active hepatitis type 2.

Science.gov (United States)

Martini, E; Abuaf, N; Cavalli, F; Durand, V; Johanet, C; Homberg, J C

1988-01-01

A new autoantibody was detected by immunoprecipitation in the serum of 21 patients with chronic active hepatitis. The antibody reacted against a soluble cytosolic antigen in liver. The antibody was organ specific but not species specific and was therefore called anti-liver cytosol antibody Type 1 (anti-LC1). In seven of 21 cases, no other autoantibody was found; the remaining 14 cases had anti-liver/kidney microsome antibody Type 1 (anti-LKM1). With indirect immunofluorescence, a distinctive staining pattern was observed with the seven sera with anti-LC1 and without anti-LKM1. The antibody stained the cytoplasm of hepatocytes from four different animal species and spared the cellular layer around the central veins of mouse and rat liver that we have called juxtavenous hepatocytes. The immunofluorescence pattern disappeared after absorption of sera by a liver cytosol fraction. The 14 sera with both antibodies displayed anti-LC1 immunofluorescent pattern after absorption of anti-LKM1 by the liver microsomal fraction. The anti-LC1 was found in the serum only in patients with chronic active hepatitis of unknown cause. Anti-LC1 antibody was not found in sera from 100 patients with chronic active hepatitis associated with anti-actin antibody classic chronic active hepatitis Type 1, 100 patients with primary biliary cirrhosis, 157 patients with drug-induced hepatitis and a large number of patients with liver and nonliver diseases. This new antibody was considered a second marker of chronic active hepatitis associated with anti-LKM1 (anti-LKM1 chronic active hepatitis) or autoimmune chronic active hepatitis Type 2.

Evaluation of hepatic blood flow using 99mTc-GSA in rats with hepatic blood flow manipulation

International Nuclear Information System (INIS)

Hiraguchi, Etsuo

1995-01-01

Blood clearance and hepatic uptake parameters of 99m Tc-DTPA-galactosyl human serum albumin ( 99m Tc-GSA) were evaluated in two groups of rats, normal liver group and CCl 4 induced chronic liver injury group. In each group, four subgroups were classified as follows: simple laparotomy (LAP), hepatic artery ligation (HAL), portal vein ligation (PVL) and both hepatic artery and portal vein ligation (HAL+PVL). 99m Tc-GSA was intravenously injected (50 μg/100 g B.W.) to rats. Heart and liver were targetted as region of interest and time activity curves (TACs) were obtained. The blood clearance parameters (HH4 and Kd) and the hepatic uptake parameters (LHL4 and Ku) were calculated from these TACs. In normal liver group, the mean HH4 of LAP was significantly different from those of PVL and HAL+PVL. Similarly, the other three parameters (LHL4, Kd and Ku) of LAP were significantly different from those of PVL and HAL+PVL. CCl 4 induced chronic liver injury group showed significant difference on all four parameters in four subgroups. Hepatic tissue blood flow rates (HTBFR) calculated by Laser Doppler flowmeter correlated well with 99m Tc-GSA parameters in both groups. These results suggest that 99m Tc-GSA is useful to estimate hepatic blood flow not only in rats with normal liver, but also in rats with CCl 4 induced chronic liver injury. (author)

Effects of raloxifene on portal hypertension and hepatic encephalopathy in cirrhotic rats.

Science.gov (United States)

Chang, Ching-Chih; Lee, Wen-Shin; Chuang, Chiao-Lin; Hsin, I-Fang; Hsu, Shao-Jung; Chang, Ting; Huang, Hui-Chun; Lee, Fa-Yauh; Lee, Shou-Dong

2017-05-05

Raloxifene, a selective estrogen receptor modulator, has been used extensively for osteoporosis. In addition to the effect of osteoporosis treatment, emerging evidences show that raloxifene affects the vascular function in different tissues. Cirrhosis is characterized with portal hypertension and complicated with hepatic encephalopathy. Portal hypertension affects portal-systemic shunt which leads to hepatic encephalopathy that the vascular modulation might influence severity of hepatic encephalopathy. Herein, we evaluated the impact of raloxifene on bile duct ligation (BDL)-induced cirrhotic rats. The female Sprague-Dawley rats received BDL plus ovariectomy or sham-operation. Four weeks later, rats were divided into 2 subgroups respectively to receive of raloxifene (10mg/kg/day) or saline (vehicle) for 14 days. On the 43th day, motor activities and hemodynamic parameters were measured. Hepatic and vascular mRNA and protein expressions were determined. The histopathological change of liver was examined. We found that the liver biochemistry, ammonia level and motor activity were similar between cirrhotic rats with or without raloxifene administration. The hemodynamic parameters were not significantly different except that raloxifene reduced portal venous inflow. Raloxifene exacerbated hepatic fibrosis and up-regulated hepatic endothelin-1 and cyclooxygenase 2 protein expressions. In addition, raloxifene modulated the mRNA expressions of endothelial nitric oxide synthase, cyclooxygenase and endothelin-1 in the superior mesenteric artery and collateral vessel. In conclusion, raloxifene aggravates hepatic fibrosis and decreases portal venous inflow in cirrhotic rats without adversely affecting portal hypertension and hepatic encephalopathy. The modulation of hepatic and vascular endothelin-1, endothelial nitric oxide synthase and cyclooxygenase expressions may play a role in the mechanism. Copyright © 2017 Elsevier B.V. All rights reserved.

Hepatic oxidative stress, genotoxicity and vascular dysfunction in lean or obese zucker rats

DEFF Research Database (Denmark)

Løhr, Mille; Folkmann, Janne Kjærsgaard; Sheykhzade, Majid

2015-01-01

Metabolic syndrome is associated with increased risk of cardiovascular disease, which could be related to oxidative stress. Here, we investigated the associations between hepatic oxidative stress and vascular function in pressurized mesenteric arteries from lean and obese Zucker rats at 14, 24 an......-generated DNA damage despite substantial hepatic steatosis.......Metabolic syndrome is associated with increased risk of cardiovascular disease, which could be related to oxidative stress. Here, we investigated the associations between hepatic oxidative stress and vascular function in pressurized mesenteric arteries from lean and obese Zucker rats at 14, 24...... and 37 weeks of age. Obese Zucker rats had more hepatic fat accumulation than their lean counterparts. Nevertheless, the obese rats had unaltered age-related level of hepatic oxidatively damaged DNA in terms of formamidopyrimidine DNA glycosylase (FPG) or human oxoguanine DNA glycosylase (hOGG1...

Hepatic microsomal metabolism of BDE-47 and BDE-99 by lesser snow geese and Japanese quail.

Science.gov (United States)

Krieger, Lisa K; Szeitz, András; Bandiera, Stelvio M

2017-09-01

In the present study, we investigated the oxidative biotransformation of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) and 2,2',4,4',5-pentabromodiphenyl ether (BDE-99) by liver microsomes from wild lesser snow geese (Chen caerulescens caerulescens) and domesticated Japanese quail (Coturnix japonica). Formation of hydroxy-metabolites was analyzed using an ultra-high performance liquid chromatography-tandem mass spectrometry-based method. Incubation of BDE-47 with avian liver microsomes produced sixteen hydroxy-metabolites, eight of which were identified using authentic standards. The major metabolites formed by liver microsomes from individual lesser snow geese were 4-hydroxy-2,2',3,4'-tetrabromodiphenyl ether (4-OH-BDE-42), 3-hydroxy-2,2',4,4'-tetrabromodiphenyl ether (3-OH-BDE-47), and 4'-hydroxy-2,2',4,5'-tetrabromodiphenyl ether (4'-OH-BDE-49). By comparison, 4-OH-BDE-42 and 4'-OH-BDE-49, but not 3-OH-BDE-47, were major metabolites of Japanese quail liver microsomes. Unidentified metabolites included monohydroxy- and dihydroxy-tetrabromodiphenyl ethers. Incubation of BDE-99 with avian liver microsomes produced seventeen hydroxy-metabolites, twelve of which were identified using authentic standards. The major metabolites formed by lesser snow goose liver microsomes were 2,4,5-tribromophenol, 3-OH-BDE-47, 4'-OH-BDE-49, 4-hydroxy-2,2',3,4',5-pentabromodiphenyl ether (4-OH-BDE-90), and 5'-hydroxy-2,2',4,4',5-pentabromodiphenyl ether (5'-OH-BDE-99). By comparison, the major metabolites produced by liver microsomes from Japanese quail included 6-hydroxy-2,2',4,4'-tetrabromodiphenyl ether (6-OH-BDE-47) and 2-hydroxy-2',3,4,4',5-pentabromodiphenyl ether (2-OH-BDE-123), but not 3-OH-BDE-47. Unidentified metabolites consisted of monohydroxy-pentabromodiphenyl ethers, monohydroxy-tetrabromodiphenyl ethers and dihydroxy-tetrabromodiphenyl ethers. Another difference between the two species was that formation rates of BDE-47 and BDE-99 metabolites were greater with liver

Esculetin Ameliorates Carbon Tetrachloride-Mediated Hepatic Apoptosis in Rats

Directory of Open Access Journals (Sweden)

Chuan-Sung Chiu

2011-06-01

Full Text Available Esculetin (ESC is a coumarin that is present in several plants such as Fraxinus rhynchophylla and Artemisia capillaris. Our previous study found that FR ethanol extract (FREtOH significantly ameliorated rats’ liver function. This study was intended to investigate the protective mechanism of ESC in hepatic apoptosis in rats induced by carbon tetrachloride. Rat hepatic apoptosis was induced by oral administration of CCl4. All rats were administered orally with CCl4 (20%, 0.5 mL/rat twice a week for 8 weeks. Rats in the ESC groups were treated daily with ESC, and silymarin group were treated daily with silymarin. Serum alanine aminotransferase (ALT, aspartate aminotransferase (AST as well as the activities of the anti-oxidative enzymes glutathione peroxidase (GPx, superoxide dismutase (SOD, and catalase in the liver were measured. In addition, expression of liver apoptosis proteins and anti-apoptotic proteins were detected. ESC (100, 500 mg/kg significantly reduced the elevated activities of serum ALT and AST caused by CCl4 and significantly increased the activities of catalase, GPx and SOD. Furthermore, ESC (100, 500 mg/kg significantly decreased the levels of the proapoptotic proteins (t-Bid, Bak and Bad and significantly increased the levels of the anti-apoptotic proteins (Bcl-2 and Bcl-xL. ESC inhibited the release of cytochrome c from mitochondria. In addition, the levels of activated caspase-9 and activated caspase-3 were significantly decreased in rats treated with ESC than those in rats treated with CCl4 alone. ESC significantly reduced CCl4-induced hepatic apoptosis in rats.

Rat liver contains a limited number of binding sites for hepatic lipase

NARCIS (Netherlands)

G.C. Schoonderwoerd (Kees); A.J.M. Verhoeven (Adrie); H. Jansen (Hans)

1994-01-01

textabstractThe binding of hepatic lipase to rat liver was studied in an ex vivo perfusion model. The livers were perfused with media containing partially purified rat hepatic lipase or bovine milk lipoprotein lipase. The activity of the enzymes was determined in the

One-electron reduction of mitomycin c by rat liver : role of cytochrome P-450 and NADPH-cytochrome P-450 reductase

NARCIS (Netherlands)

Vromans, R M; Van de Straat, R; Groeneveld, M.; Vermeulen, N P

1. The role of cytochrome P-450 in the one-electron reduction of mitomycin c was studied in rat hepatic microsomal systems and in reconstituted systems of purified cytochrome P-450. Formation of H2O2 from redox cycling of the reduced mitomycin c in the presence of O2 and the alkylation of

Early effects of dietary orotic acid upon liver lipid synthesis and bile cholesterol secretion in rats

International Nuclear Information System (INIS)

Tokmakjian, S.D.; Haines, D.S.

1985-01-01

Dietary orotic acid is known to cause impaired fatty acid synthesis and increased cholesterol synthesis in rats. The authors found that the impaired fatty acid synthesis occurs during the first day of orotic acid feeding and, in studies with albumin-bound [1- 14 C]palmitic acid, an associated decrease in the rate of esterification of this fatty acid into triacylglycerol, phospholipid, and cholesteryl ester was observed. These changes may result from the known decreases in liver levels of adenine nucleotides or, as reported here, from decreased liver CoASH levels in orotic acid-fed rats. The increase in hepatic cholesterol synthesis occurred during the second day of orotic acid feeding. It was detected by increased incorporation of [1,2- 14 C]acetate into cholesterol by liver slices and by a 7-fold increase in HMG-CoA reductase activity. At the same time the biliary output of cholesterol was increased 2-fold and studies using 3 H 2 O revealed that the output of newly synthesized cholesterol in bile was increased 5-fold. The content of cholesteryl ester in hepatic microsomes decreased during orotic acid feeding but free cholesterol was unchanged. The findings are interpreted to suggest that the increased bile cholesterol secretion caused by orotic acid is a result of impaired hepatic cholesterol esterification and that the increase in HMG-CoA reductase activity is a result of diminished negative feedback due to the depleted content of cholesteryl ester in the hepatic microsomes

Comparison of epoxide and free-radical mechanisms for activation of benzo[a]pyrene by Sprague-Dawley rat liver microsomes

International Nuclear Information System (INIS)

Selkirk, J.K.

1980-01-01

Coincubation of [6- 3 H]benzo[a]pyrene ([6- 3 H]BP) and [ 14 C]BP with SD rat liver microsomes produced metabolic profiles that showed that the C-6 of BP was not affected by formation of 4,5-dihydro-4,5-dihydroxy-BP, 7,8-dihydro-7,8-dihydroxy-BP, and 9,10-dihydro-9,10-dihydroxy-BP nor the 3- and 9-phenols of BP. Complete retention of tritium at C-6, except in the three quinones, confirmed the radical-cation model for formation of the 6-oxo-radical followed by oxidation to quinone. Epoxide formation at the carcinogenically active regions of BP appeared to biochemically isolate from 6-position activation and suggested that the microsomal epoxide pathway is unrelated to the radicalcation scheme. These molar ratios derived from double-label experiments reinforced the current literature that indicates the epoxide mechanism as the major pathway toward carcinogenic forms of BP

Metabolism of indole alkaloid tumor promoter, (-)-indolactam V, which has the fundamental structure of teleocidins, by rat liver microsomes

Energy Technology Data Exchange (ETDEWEB)

Hagiwara, N.; Irie, K.; Tokuda, H.; Koshimizu, K.

1987-07-01

Metabolic activation and/or deactivation of indole alkaloid tumor promoter, (-)-indolactam V (ILV), was examined using rat liver microsomes. Reaction of ILV with the microsomes supplemented with NADPH and MgCl/sub 2/ gave three major metabolites, which were identified as (-)-N13-desmethylindolactam V and two diastereomers of (-)-2-oxyindolactam V at C-3. The tumor-promoting activities of these metabolites were evaluated by induction of Epstein-Barr virus early antigen and inhibition of specific binding of (/sup 3/H)-12-O-tetradecanoylphorbol-13-acetate to a mouse epidermal particulate fraction, and proved to be conspicuously lower than that of ILV. These results demonstrate that the metabolism of ILV results in detoxification, and that it itself is the tumor-promoting entity. Studies on the enzymes concerned with this metabolism suggested the involvement of cytochrome P-450-containing mixed-function oxidases. Similar deactivation seems to be possible by skin, where the mixed-function oxidases are known to exist.

High-fructose corn syrup-55 consumption alters hepatic lipid metabolism and promotes triglyceride accumulation.

Science.gov (United States)

Mock, Kaitlin; Lateef, Sundus; Benedito, Vagner A; Tou, Janet C

2017-01-01

High-fructose corn syrup-55 (HFCS-55) has been suggested to be more lipogenic than sucrose, which increases the risk for nonalcoholic fatty liver disease (NAFLD) and dyslipidemia. The study objectives were to determine the effects of drinking different sugar-sweetened solutions on hepatic gene expression in relation to liver fatty acid composition and risk of NAFLD. Female rats were randomly assigned (n=7 rats/group) to drink water or water sweetened with 13% (w/v) HFCS-55, sucrose or fructose for 8 weeks. Rats drinking HFCS-55 solution had the highest (P=.03) hepatic total lipid and triglyceride content and histological evidence of fat infiltration. Rats drinking HFCS-55 solution had the highest hepatic de novo lipogenesis indicated by the up-regulation of stearoyl-CoA desaturase-1 and the highest (Ptriglyceride-rich lipoprotein from the liver was increased as shown by up-regulation of gene expression of microsomal triglyceride transfer protein in rats drinking sucrose, but not HFCS-55 solution. The observed lipogenic effects were attributed to the slightly higher fructose content of HFCS-55 solution in the absence of differences in macronutrient and total caloric intake between rats drinking HFCS-55 and sucrose solution. Results from gene expression and fatty acid composition analysis showed that, in a hypercaloric state, some types of sugars are more detrimental to the liver. Based on these preclinical study results, excess consumption of caloric sweetened beverage, particularly HFCS-sweetened beverages, should be limited. Published by Elsevier Inc.

Blarina brevicauda as a biological monitor of polychlorinated biphenyls: evaluation of hepatic cytochrome P450 induction.

Science.gov (United States)

Russell, Julie S; Halbrook, Richard S; Woolf, Alan; French, John B; Melancon, Mark J

2004-08-01

We assessed the value of short-tailed shrews (Blarina brevicauda) as a possible biomonitor for polychlorinated biphenyl pollution through measurement of the induction of hepatic cytochrome P450 and associated enzyme activities. First, we checked the inducibility of four monooxygenases (benzyloxyresorufin-O-dealkylase [BROD], ethoxyresorufin-O-dealkylase [EROD], methoxyresorufin-O-dealkylase [MROD], and pentoxyresorufin-O-dealkylase [PROD]) by measuring the activity of these enzymes in hepatic microsomes prepared from shrews injected with beta-naphthoflavone (betaNF) or phenobarbital (PB), typical inducers of cytochrome P4501A (CYP1A) and CYP2B enzyme families, respectively. Enzyme activity was induced in shrews that received betaNF but not in shrews that received PB; PROD was not induced by either exposure. Later, shrews were exposed to a mixture of polychlorinated biphenyls (PCBs) (Aroclor 1242:1254, in 1:2 ratio) at 0.6, 9.6, and 150 ppm in food, for 31 d. Induction in these shrews was measured by specific enzyme activity (BROD, EROD, and MROD) in hepatic microsomes, by western blotting of solubilized microsomes against antibodies to CYP1A or CYP2B, and by duration of sodium pentobarbital-induced sleep. These three CYP enzymes were induced in shrews by PCBs at similar levels of exposure as in cotton rat (Sigmodon hispidus). Neither sleep time nor the amount of CYP2B family protein were affected by PCB exposure. Blarina brevicauda can be a useful biomonitor of PCBs that induce CYP1A, especially in habitats where they are the abundant small mammal.

Lansoprazole increases testosterone metabolism and clearance in male Sprague-Dawley rats: implications for leydig cell carcinogenesis

International Nuclear Information System (INIS)

Coulson, Michelle; Gibson, G. Gordon; Plant, Nick; Hammond, Tim; Graham, Mark

2003-01-01

Leydig cell tumours (LCTs) are frequently observed during rodent carcinogenicity studies, however, the significance of this effect to humans remains a matter of debate. Many chemicals that produce LCTs also induce hepatic cytochromes P450 (CYPs), but it is unknown whether these two phenomena are causally related. Our aim was to investigate the existence of a liver-testis axis wherein microsomal enzyme inducers enhance testosterone metabolic clearance, resulting in a drop in circulating hormone levels and a consequent hypertrophic response from the hypothalamic-pituitary-testis axis. Lansoprazole was selected as the model compound as it induces hepatic CYPs and produces LCTs in rats. Male Sprague-Dawley rats were dosed with lansoprazole (150 mg/kg/day) or vehicle for 14 days. Lansoprazole treatment produced effects on the liver consistent with an enhanced metabolic capacity, including significant increases in relative liver weights, total microsomal CYP content, individual CYP protein levels, and enhanced CYP-dependent testosterone metabolism in vitro. Following intravenous administration of [ 14 C]testosterone, lansoprazole-treated rats exhibited a significantly smaller area under the curve and significantly higher plasma clearance. Significant reductions in plasma and testicular testosterone levels were observed, confirming the ability of this compound to perturb androgen homeostasis. No significant changes in plasma LH, FSH, or prolactin levels were detected under our experimental conditions. Lansoprazole treatment exerted no marked effects on testicular testosterone metabolism. In summary, lansoprazole treatment induced hepatic CYP-dependent testosterone metabolism in vitro and enhanced plasma clearance of radiolabelled testosterone in vivo. These effects may contribute to depletion of circulating testosterone levels and hence play a role in the mode of LCT induction in lansoprazole-treated rats

Formation of glutathione conjugates by reactive metabolites of vinylidene chloride in microsomes and isolated hepatocytes

International Nuclear Information System (INIS)

Liebler, D.C.; Meredith, M.J.; Guengerich, F.P.

1985-01-01

Oxidation of the vinyl halide carcinogen and hepatotoxin vinylidene chloride (VDC) by microsomal cytochrome P-450 yields 2,2-dichloroacetaldehyde, 2-chloroacetyl chloride, 2-chloroacetic acid, and 1,1-dichloroethylene oxide. The roles of these metabolites in covalent modification of proteins and reduced glutathione (GSH) were examined. 2-Chloroacetyl chloride reacted with model thiols at least 10(3)-fold faster than did 1,1-dichloroethylene oxide and at least 10(5)-fold faster than did 2,2-dichloroacetaldehyde or 2-chloroacetic acid. Microsomal covalent binding of [ 14 C]VDC was inhibited by GSH but not by lysine, suggesting that protein thiols, rather than amino groups, are major targets. Liver microsomes catalyzed the formation of three GSH:VDC metabolite conjugates, identified as S-(2,2-dichloro-1-hydroxy)ethylglutathione, 2-(S-glutathionyl)acetate, and S-(2-glutathionyl)acetylglutathione, a novel conjugate containing both stable (thioether) and labile (thioester) linkages. The latter two conjugates also were formed in isolated rat hepatocytes and measurable amounts of 2-(S-glutathionyl)acetate were released into the incubation medium. Both 2-(S-glutathionyl)acetate and S-(2-glutathionyl)acetylglutathione were formed with [ 35 S]GSH added to the hepatic medium, indicating that reactive VDC metabolites are capable of crossing the plasma membrane to react with extracellular targets. Unlabeled S-(2-glutathionyl)-acetylglutathione underwent carbonyl substitution with added [ 35 S]GSH, suggesting that this conjugate may participate in modification of protein thiols. This conjugate also underwent hydrolysis with a half-life of approximately 3 hr. GSH:VDC metabolite conjugates may serve as accessible models for labile covalent adducts formed between VDC metabolites and protein thiols

Liver/kidney microsomal antibody type 1 and liver cytosol antibody type 1 concentrations in type 2 autoimmune hepatitis.

Science.gov (United States)

Muratori, L; Cataleta, M; Muratori, P; Lenzi, M; Bianchi, F B

1998-05-01

Liver/kidney microsomal antibody type 1 (LKM1) and liver cytosol antibody type 1 (LC1) are the serological markers of type 2 autoimmune hepatitis (AIH). Since LKM1 and LC1 react against two distinct liver specific autoantigens (cytochrome P450IID6 (CYP2D6) and a 58 kDa cytosolic polypeptide respectively), the aim was to see whether LKM1 and LC1 concentrations correlate with liver disease activity. Twenty one patients with type 2 AIH were studied. All sera were tested by indirect immunofluorescence, counterimmunoelectrophoresis, and immunoblotting visualised by enhanced chemiluminescence. To evaluate LKM1 and LC1 levels, the 50 kDa microsomal reactivity (corresponding to CYP2D6) and the 58 kDa cytosolic reactivity were quantified by densitometric analysis. Seven patients were positive for LKM1, nine for LC1, and five for both. Serial serum samples at onset and during immunosuppressive treatment were analysed in 13 patients (four positive for LKM1, six positive for LC1 and three positive for both). During remission, LKM1 concentration remained essentially unchanged in six of seven patients, and decreased in only one. Conversely, in two of nine patients, LC1 was completely lost, and, in the remaining seven, LC1 concentration was reduced by more than 50%. After immunosuppression tapering or withdrawal, flare ups of liver necrosis ensued with increasing LC1 concentration, but not LKM1. LC1 concentration, at variance with that of LKM1, parallels liver disease activity, and its participation in the pathogenic mechanisms of liver injury can be hypothesised.

JTT-130, a microsomal triglyceride transfer protein (MTP inhibitor lowers plasma triglycerides and LDL cholesterol concentrations without increasing hepatic triglycerides in guinea pigs

Directory of Open Access Journals (Sweden)

Shrestha Sudeep

2005-09-01

Full Text Available Abstract Background Microsomal transfer protein inhibitors (MTPi have the potential to be used as a drug to lower plasma lipids, mainly plasma triglycerides (TG. However, studies with animal models have indicated that MTPi treatment results in the accumulation of hepatic TG. The purpose of this study was to evaluate whether JTT-130, a unique MTPi, targeted to the intestine, would effectively reduce plasma lipids without inducing a fatty liver. Methods Male guinea pigs (n = 10 per group were used for this experiment. Initially all guinea pigs were fed a hypercholesterolemic diet containing 0.08 g/100 g dietary cholesterol for 3 wk. After this period, animals were randomly assigned to diets containing 0 (control, 0.0005 or 0.0015 g/100 g of MTPi for 4 wk. A diet containing 0.05 g/100 g of atorvastatin, an HMG-CoA reductase inhibitor was used as the positive control. At the end of the 7th week, guinea pigs were sacrificed to assess drug effects on plasma and hepatic lipids, composition of LDL and VLDL, hepatic cholesterol and lipoprotein metabolism. Results Plasma LDL cholesterol and TG were 25 and 30% lower in guinea pigs treated with MTPi compared to controls (P Conclusion These results suggest that JTT-130 could have potential clinical applications due to its plasma lipid lowering effects with no alterations in hepatic lipid concentrations.

Effects of thiol antioxidants on the atropselective oxidation of 2,2',3,3',6,6'-hexachlorobiphenyl (PCB 136) by rat liver microsomes.

Science.gov (United States)

Wu, Xianai; Lehmler, Hans-Joachim

2016-02-01

Chiral polychlorinated biphenyl (PCB) congeners, such as PCB 136, are atropselectively metabolized to various hydroxylated PCB metabolites (HO-PCBs). The present study investigates the effect of two thiol antioxidants, glutathione and N-acetyl-cysteine (NAC), on profiles and chiral signatures of PCB 136 and its HO-PCB metabolites in rat liver microsomal incubations. Liver microsomes prepared from rats pretreated with phenobarbital were incubated with PCB 136 (5 μM) in the presence of the respective antioxidant (0-10 mM), and levels and chiral signatures of PCB 136 and its HO-PCB metabolites were determined. Three metabolites, 5-136 (2,2',3,3',6,6'-hexachlorobiphenyl-5-ol), 4-136 (2,2',3,3',6,6'-hexachlorobiphenyl-4-ol), and 4,5-136 (2,2',3,3',6,6'-hexachlorobiphenyl-4,5-diol), were detected in all incubations, with 5-136 being the major metabolite. Compared to microsomal incubations without antioxidant, levels of 4,5-136 increased with increasing antioxidant concentration, whereas levels of PCB 136 and both mono-HO-PCBs were not affected by the presence of either antioxidant. PCB 136, 4-136, and 5-136 displayed significant atropisomeric enrichment; however, the direction and extent of the atropisomeric enrichment was not altered in the presence of an antioxidant. Because 4,5-136 can either be conjugated to a sulfate or glucuronide metabolite that is readily excreted or further oxidized a potentially toxic PCB 136 quinone, the effect of both thiol antioxidants on 4,5-136 formation suggests that disruptions of glutathione homeostasis may alter the balance between both metabolic pathways and, thus, PCB 136 toxicity in vivo.

A reliable radiochromatographic assay technique for hepatic microsomal 16α-hydroxylase activity towards oestrone 3-sulphate

International Nuclear Information System (INIS)

Tsoutsoulis, C.J.; Hobkirk, R.

1980-01-01

A reliable procedure for the assay of liver microsomal 16α-hydroxylation of oestrone 3-sulphate has been developed for the guinea pig. It is based on the rapid, quantitative separation of oestradiol and oestriol by Sephadex LH-20 columns after the chemical reduction and enzymic hydrolysis of the incubation products. Microsomal preparations and incubation conditions that optimized 16α-hydroxylation of oestrone 3-sulphate were employed. Under these circumstances, reduction of the substrate at C-17 and hydrolysis of the sulphate were minimized. Conditions were established that yielded reaction linearity with respect to time and microsomal concentration. This hydroxylation had an absolute requirement for NADPH, which could not be satisfied by NADH. Apparent Ksub(m) values for oestrone 3-sulphate and NADPH, under the conditions used, were 14μM and 0.17mM respectively. 16α-hydroxylase activity was present in the liver microsomal fraction from heavily pigmented, female English Shorthaired guinea pigs. Much lower activity was detected in mature pigmented males and albino females. No activity could be demonstrated in mature, albino males. (author)

Carbonated soft drinks alter hepatic cytochrome P450 isoform expression in Wistar rats.

Science.gov (United States)

Alkhedaide, Adel; Soliman, Mohamed Mohamed; Ibrahim, Zein Shaban

2016-11-01

The aim of the current study was to examine the effects of chronic consumption of soft drinks (SDs) on hepatic oxidative stress and cytochrome P450 enzymes (CYPs) expression in the livers of Wistar rats. For 3 consecutive months, the rats had free access to three different soft drinks, Coca-Cola, Pepsi-Cola and 7-UP. The rats were subsequently compared with control group rats that had consumed water. Blood and hepatic tissue samples were assayed for the changes in antioxidants, liver function biomarkers and hepatic gene expression for different isoforms of hepatic CYP. The results indicated that SD consumption (SDC) decreased serum antioxidant levels and increased malondialdehyde secretion, and increased liver biomarkers (glutamate pyruvate transaminase and glutamate oxaloacetate). SD induced alterations in mRNA expression of hepatic antioxidants and cytochrome isoforms. The expression of peroxidase, catalase, CYP1A2, CYP3A2 and CYP2C11 in the liver were upregulated following SDC. By contrast, CYP2B1 was downregulated after 3 months of SDC in liver tissue samples. Thus, the present findings indicate that SDs induced oxidative stress in the liver of Wistar rats and for the first time, to the best of our knowledge, indicate that SDC disrupts hepatic CYP enzymes that may affect drug metabolism. Therefore, drug-dosing programs should be carefully designed to take these novel findings into consideration for the treatment of diseases.

Studies on the metabolism of chlorotrianisene to a reactive intermediate and subsequent covalent binding to microsomal proteins

International Nuclear Information System (INIS)

Juedes, M.J.

1989-01-01

The studies on chlorotrianisene were conducted to determine whether metabolism of chlorotrianisene occurs via the cytochrome P450 monooxygenase system and whether a reactive intermediate is being formed that is capable of binding covalently to microsomal proteins. [ 3 H]-chlorotrianisene was incubated with liver microsomes supplemented with NADPH. At the termination of the incubation, the protein was trapped on a glass filter and the unbound chlorotrianisene was removed by extensive washing of the protein with organic solvent. A dramatic stimulation of covalent binding was demonstrated in microsomes from rats treated with methylcholanthrene (60 fold increase) versus control or phenobarbital treatment. Verification of covalent binding was achieved by localization of radiolabeled bands following sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of the macromolecules in the incubation mixture. Further analysis of the radiolabeled macromolecules separated on SDS-PAGE revealed that these macromolecules were degraded by protease degradation indicating that the macromolecules were proteins. Further investigations were done to determine the cause of the dramatic stimulation of covalent binding detected in microsomes from methylcholanthrene treated rats versus control or phenobarbital treated rats. Further evidence for the participation of P-450c was obtained with a reconstituted cytochrome P-450 system. Incubations of chlorotrianisene with reconstituted P-450c and NADPH-cytochrome P-450 reductase exhibited covalent binding characteristics comparable to those seen in microsomal incubations. Investigations into the nature of the binding site and the reactive intermediate are currently being conducted. By analyzing the BSA adduct, the author intends to isolate the specific amino acid binding site(s)

Mangiferin treatment inhibits hepatic expression of acyl-coenzyme A:diacylglycerol acyltransferase-2 in fructose-fed spontaneously hypertensive rats: a link to amelioration of fatty liver

Energy Technology Data Exchange (ETDEWEB)

Xing, Xiaomang; Li, Danyang; Chen, Dilong; Zhou, Liang [Faculty of Basic Medical Sciences, Chongqing Medical University, Chongqing 400016 China (China); Chonan, Ritsu [Koei Kogyo Co., Ltd., Tokyo, 101-0063 Japan (Japan); Yamahara, Johji [Pharmafood Institute, Kyoto, 602-8136 Japan (Japan); Wang, Jianwei, E-mail: wangjianwei1968@gmail.com [Department of Traditional Chinese Medicine, Chongqing Medical University, Chongqing 400016 China (China); Li, Yuhao, E-mail: yuhao@sitcm.edu.au [Endocrinology and Metabolism Group, Sydney Institute of Health Sciences/Sydney Institute of Traditional Chinese Medicine, NSW 2000 Australia (Australia)

2014-10-15

Mangiferin, a xanthone glucoside, and its associated traditional herbs have been demonstrated to improve abnormalities of lipid metabolism. However, its underlying mechanisms remain largely unclear. This study investigated the anti-steatotic effect of mangiferin in fructose-fed spontaneously hypertensive rat (SHR)s that have a mutation in sterol regulatory element binding protein (SREBP)-1. The results showed that co-administration of mangiferin (15 mg/kg, once daily, by oral gavage) over 7 weeks dramatically diminished fructose-induced increases in hepatic triglyceride content and Oil Red O-stained area in SHRs. However, blood pressure, fructose and chow intakes, white adipose tissue weight and metabolic parameters (plasma concentrations of glucose, insulin, triglyceride, total cholesterol and non-esterified fatty acids) were unaffected by mangiferin treatment. Mechanistically, mangiferin treatment suppressed acyl-coenzyme A:diacylglycerol acyltransferase (DGAT)-2 expression at the mRNA and protein levels in the liver. In contrast, mangiferin treatment was without effect on hepatic mRNA and/or protein expression of SREBP-1/1c, carbohydrate response element binding protein, liver pyruvate kinase, fatty acid synthase, acetyl-CoA carboxylase-1, stearoyl-CoA desaturase-1, DGAT-1, monoacyglycerol acyltransferase-2, microsomal triglyceride transfer protein, peroxisome proliferator-activated receptor-alpha, carnitine palmitoyltransferase-1 and acyl-CoA oxidase. Collectively, our results suggest that mangiferin treatment ameliorates fatty liver in fructose-fed SHRs by inhibiting hepatic DGAT-2 that catalyzes the final step in triglyceride biosynthesis. The anti-steatotic effect of mangiferin may occur independently of the hepatic signals associated with de novo fatty acid synthesis and oxidation. - Highlights: • We investigated the anti-steatotic effect of mangiferin (MA) in fructose-fed SHR. • MA (15 mg/kg/day for 7 weeks) ameliorated fructose-induced fatty liver in

Mangiferin treatment inhibits hepatic expression of acyl-coenzyme A:diacylglycerol acyltransferase-2 in fructose-fed spontaneously hypertensive rats: a link to amelioration of fatty liver

International Nuclear Information System (INIS)

Xing, Xiaomang; Li, Danyang; Chen, Dilong; Zhou, Liang; Chonan, Ritsu; Yamahara, Johji; Wang, Jianwei; Li, Yuhao

2014-01-01

Mangiferin, a xanthone glucoside, and its associated traditional herbs have been demonstrated to improve abnormalities of lipid metabolism. However, its underlying mechanisms remain largely unclear. This study investigated the anti-steatotic effect of mangiferin in fructose-fed spontaneously hypertensive rat (SHR)s that have a mutation in sterol regulatory element binding protein (SREBP)-1. The results showed that co-administration of mangiferin (15 mg/kg, once daily, by oral gavage) over 7 weeks dramatically diminished fructose-induced increases in hepatic triglyceride content and Oil Red O-stained area in SHRs. However, blood pressure, fructose and chow intakes, white adipose tissue weight and metabolic parameters (plasma concentrations of glucose, insulin, triglyceride, total cholesterol and non-esterified fatty acids) were unaffected by mangiferin treatment. Mechanistically, mangiferin treatment suppressed acyl-coenzyme A:diacylglycerol acyltransferase (DGAT)-2 expression at the mRNA and protein levels in the liver. In contrast, mangiferin treatment was without effect on hepatic mRNA and/or protein expression of SREBP-1/1c, carbohydrate response element binding protein, liver pyruvate kinase, fatty acid synthase, acetyl-CoA carboxylase-1, stearoyl-CoA desaturase-1, DGAT-1, monoacyglycerol acyltransferase-2, microsomal triglyceride transfer protein, peroxisome proliferator-activated receptor-alpha, carnitine palmitoyltransferase-1 and acyl-CoA oxidase. Collectively, our results suggest that mangiferin treatment ameliorates fatty liver in fructose-fed SHRs by inhibiting hepatic DGAT-2 that catalyzes the final step in triglyceride biosynthesis. The anti-steatotic effect of mangiferin may occur independently of the hepatic signals associated with de novo fatty acid synthesis and oxidation. - Highlights: • We investigated the anti-steatotic effect of mangiferin (MA) in fructose-fed SHR. • MA (15 mg/kg/day for 7 weeks) ameliorated fructose-induced fatty liver in

Induction of 1-Acylglycerophosphocholine Acyltransferase Genes by Fibrates in the Liver of Rats

OpenAIRE

山崎, 研; 若林, 美智子; 池田, 英里香; 田中, 静代; 坂本, 武史; 光本, 篤史; 工藤, なをみ; 川嶋, 洋一

2012-01-01

The effect of fibrates (clofibric acid, bezafibrate and fenofibrate) on the gene expression and activity of 1-acylglycerophosphocholine acyltransferase (LPCAT) was investigated. The administration of 0.1% (w/w) clofibric acid, bezafibrate or fenofibrate in diet for 14?d to rats induced LPCAT activity in hepatic microsomes in the following order: fenofibrate>bezafibrate>clofibric acid. The LPCAT induced by fenofibrate preferred to arachidonoyl-CoA and linoleoyl-CoA to a greater extent than did...

Decreased liver triglyceride content in adult rats exposed to protein restriction during gestation and lactation: role of hepatic triglyceride utilization.

Science.gov (United States)

Qasem, Rani J; Li, Jing; Tang, Hee Man; Browne, Veron; Mendez-Garcia, Claudia; Yablonski, Elizabeth; Pontiggia, Laura; D'Mello, Anil P

2015-04-01

We have previously demonstrated that protein restriction throughout gestation and lactation reduces liver triglyceride content in adult rat offspring. However, the mechanisms mediating the decrease in liver triglyceride content are not understood. The aim of the current study was to use a new group of pregnant animals and their offspring and determine the contribution of increased triglyceride utilization via the hepatic fatty-acid oxidation and triglyceride secretory pathways to the reduction in liver triglyceride content. Pregnant Sprague-Dawley rats received either a control or a low protein diet throughout pregnancy and lactation. Pups were weaned onto laboratory chow on day 28 and killed on day 65. Liver triglyceride content was reduced in male, but not female, low-protein offspring, both in the fed and fasted states. The reduction was accompanied by a trend towards higher liver carnitine palmitoyltransferase-1a activity, suggesting increased fatty-acid transport into the mitochondrial matrix. However, medium-chain acyl coenzyme A dehydrogenase activity within the mitochondrial matrix, expression of nuclear peroxisome proliferator activated receptor-α, and plasma levels of β-hydroxybutyrate were similar between low protein and control offspring, indicating a lack of change in fatty-acid oxidation. Hepatic triglyceride secretion, assessed by blocking peripheral triglyceride utilization and measuring serum triglyceride accumulation rate, and the activity of microsomal transfer protein, were similar between low protein and control offspring. Because enhanced triglyceride utilization is not a significant contributor, the decrease in liver triglyceride content in male low-protein offspring is likely due to alterations in liver fatty-acid transport or triglyceride biosynthesis. © 2015 Wiley Publishing Asia Pty Ltd.

Induction of 1-acylglycerophosphocholine acyltransferase genes by fibrates in the liver of rats.

Science.gov (United States)

Yamazaki, Tohru; Wakabayashi, Michiko; Ikeda, Erika; Tanaka, Shizuyo; Sakamoto, Takeshi; Mitsumoto, Atsushi; Kudo, Naomi; Kawashima, Yoichi

2012-01-01

The effect of fibrates (clofibric acid, bezafibrate and fenofibrate) on the gene expression and activity of 1-acylglycerophosphocholine acyltransferase (LPCAT) was investigated. The administration of 0.1% (w/w) clofibric acid, bezafibrate or fenofibrate in diet for 14 d to rats induced LPCAT activity in hepatic microsomes in the following order: fenofibrate>bezafibrate>clofibric acid. The LPCAT induced by fenofibrate preferred to arachidonoyl-CoA and linoleoyl-CoA to a greater extent than did LPCAT in control microsomes. The treatment with the fibrates resulted in upregulation of the relative expression of mRNAs encoding LPCAT3 and LPCAT4 in the following order: fenofibrate>bezafibrate>clofibric acid. The administration of fibrates did not change the expression of genes encoding either LPCAT1 or LPCAT2. The treatment with fibrates elevated relative levels of both mRNAs encoding Δ6 desaturase (Fads2) and Δ5 desaturase (Fads1) in the order of fenofibrate>bezafibrate>clofibric acid, and the extent of the increase in the level of Δ6 desaturase mRNA was greater than that of Δ5 desaturase. Fatty acid profile in hepatic phosphatidylcholine (PC) was significantly changed by the treatments with fibrates. These results suggest (i) that fibrates induce LPCAT activity in hepatic microsomes by elevating the expression of genes encoding LPCAT3 and LPCAT4, (ii) that the changes in fatty acid profile of hepatic PC are, in part, due to the elevated expression of two isoforms, LPCAT3 and LPCAT4, and (iii) that the ability of fibrates to induce these changes are in the order of fenofibrate>bezafibrate>clofibric acid.

Basis of aggravated hepatic lipid metabolism by chronic stress in high-fat diet-fed rat.

Science.gov (United States)

Han, Ying; Lin, Min; Wang, Xiaobin; Guo, Keke; Wang, Shanshan; Sun, Mengfei; Wang, Jiao; Han, Xiaoyu; Fu, Ting; Hu, Yang; Fu, Jihua

2015-03-01

Our previous study has demonstrated that long-term stress, known as chronic stress (CS), can aggravate nonalcoholic fatty liver disease in high-fat diet (HFD)-fed rat. In this study, we tried to figure out which lipid metabolic pathways were impacted by CS in the HFD-fed rat. Male Sprague-Dawley rats (6 weeks of age, n = 8 per group) were fed with either standard diet or HFD with or without CS exposure for 8 weeks. Hepatic lipidosis, biochemical, hormonal, and lipid profile markers in serum and liver, and enzymes involved in de novo lipogenesis (DNL) of fatty acids (FAs) and cholesterol, β-oxidation, FAs uptake, triglycerides synthesis, and very low-density lipoprotein (VLDL) assembly in the liver were detected. CS exposure reduced hepatic lipidosis but further elevated hepatic VLDL content with aggravated dyslipidemia in the HFD-fed rats. There was a synergism between CS and HFD on VLDL production and dyslipidemia. PCR and western blot assays showed that CS exposure significantly promoted hepatic VLDL assembly in rats, especially in the HFD-fed rats, while it had little impact on DNL, β-oxidation, FAs uptake, and triglycerides synthesis in the HFD-fed rats. This phenomenon was in accordance with elevated serum glucocorticoid level. The critical influence of CS exposure on hepatic lipid metabolism in the HFD-fed rats is VLDL assembly which might be regulated by glucocorticoid.

Value of MR diffusion weighted imaging in the diagnosis of hepatic fibrosis of rat

International Nuclear Information System (INIS)

Fan Guohua; Gong Jianping; Shen Junkang; Zhang Caiyuan; Xu Xiaoqiu; Xu Liang; Yu Zeyang; Zhang Wei; Wu Haorong

2013-01-01

Objective: To investigate the value of DWI in the early diagnosis and staging of hepatic fibrosis of rats. Methods: Rat model with hepatic fibrosis was established by using carbon tetrachloride. By using completely randomized design random digits table, 5 or 6 rats were assigned to model group and 1 or 2 rats to the control group. After drug administration from the second week to the end of 16th weeks, a total of 72 rats of model group and 30 rats of control group were included in this study to undergo DWI scanning. The signal intensity of DWI, the value of ADC and exponential apparent diffusion coefficient (EADC) for different b values (b = 0, 300, 600, 800 and 1000 s/mm"2 respectively) were calculated. The rats were sacrificed to death to have pathologic examination in 4h after DWI scanning. Seventy-two model rats with hepatic fibrosis were grouped according to their pathological staging. The difference of the value of hepatic signal-to-noise ratio (SNR) of different b values, and the value of ADC and EADC among control group and model groups were compared by analysis of variance with completely randomized design data rank transformation and SNK multiple comparison. The correlation of SNR and b values, and staging of hepatic fibrosis and the value of ADC and EADC were tested by rank correlation analysis. Results: (1) The signal intensity of DWI of the rats of model group showed the tendency of increase with the increase of stage of hepatic fibrosis. (2) SNR showed the tendency of decrease with the increase of b values. When b value was 600 s/mm"2 or 800 s/mm"2, SNR was 31.2 ± 11.6 and 24.8 ± 6.8 respectively and the quality of images was good. (3) There were 17 rats in grade 1, 21 rats in grade 2, 19 rats in grade 3 and 15 rats in grade 4 of hepatic fibrosis. The value of ADC of control group and of grade 1 to 4 of hepatic fibrosis were (1.65 ± 0.38) × 10"-"3, (1.34 ± 0.32) × 10"-"3, (1.04 ± 0.20) × 10"-"3, (0.99 ± 0.19) × 10"-"3, (0.62 ± 0.21) × 10

Gallic acid ameliorates hyperglycemia and improves hepatic carbohydrate metabolism in rats fed a high-fructose diet.

Science.gov (United States)

Huang, Da-Wei; Chang, Wen-Chang; Wu, James Swi-Bea; Shih, Rui-Wen; Shen, Szu-Chuan

2016-02-01

Herein, we investigated the hypoglycemic effect of plant gallic acid (GA) on glucose uptake in an insulin-resistant cell culture model and on hepatic carbohydrate metabolism in rats with a high-fructose diet (HFD)-induced diabetes. Our hypothesis is that GA ameliorates hyperglycemia via alleviating hepatic insulin resistance by suppressing hepatic inflammation and improves abnormal hepatic carbohydrate metabolism by suppressing hepatic gluconeogenesis and enhancing the hepatic glycogenesis and glycolysis pathways in HFD-induced diabetic rats. Gallic acid increased glucose uptake activity by 19.2% at a concentration of 6.25 μg/mL in insulin-resistant FL83B mouse hepatocytes. In HFD-induced diabetic rats, GA significantly alleviated hyperglycemia, reduced the values of the area under the curve for glucose in an oral glucose tolerance test, and reduced the scores of the homeostasis model assessment of insulin resistance index. The levels of serum C-peptide and fructosamine and cardiovascular risk index scores were also significantly decreased in HFD rats treated with GA. Moreover, GA up-regulated the expression of hepatic insulin signal transduction-related proteins, including insulin receptor, insulin receptor substrate 1, phosphatidylinositol-3 kinase, Akt/protein kinase B, and glucose transporter 2, in HFD rats. Gallic acid also down-regulated the expression of hepatic gluconeogenesis-related proteins, such as fructose-1,6-bisphosphatase, and up-regulated expression of hepatic glycogen synthase and glycolysis-related proteins, including hexokinase, phosphofructokinase, and aldolase, in HFD rats. Our findings indicate that GA has potential as a health food ingredient to prevent diabetes mellitus. Copyright © 2016 Elsevier Inc. All rights reserved.

[Study of enzymes of xenobiotic metabolism in the evaluation of quality of protein-containing wheat germ flakes and wallpaper flour].

Science.gov (United States)

Martinchuk, A N; E En Gyn; Safronova, A M; Peskova, E V

1991-01-01

Intake of wheat upholstery meal by growing rats was attended by a sharp decrease in the content and activity of xenobiotic metabolism enzymes in the hepatic microsomes, that was caused by the low biological value of the meal proteins. Hepatic microsomes of the rats that were fed with wheat germ flakes showed increased specific content of cytochromes P-450 and b5, but the total blood protein content per 100 g of body mass was lower than during casein consumption. No significant changes were detected in hydroxylation rate of benz(a)pyrene, aniline and ethylmorphine. During consumption of wheat germ flakes induction of UDP-glucuronide-transferase was detected in hepatic microsomes. Wheat germ flakes induced a 5-fold increase of Se-dependent glutathione peroxidase activity. Wheat germ flakes produced no significant effect on glutathione-S-aryltransferase and glutathione reductase activity.

Dietary Iron Supplementation Alters Hepatic Inflammation in a Rat Model of Nonalcoholic Steatohepatitis

Directory of Open Access Journals (Sweden)

Machi Atarashi

2018-02-01

Full Text Available Nonalcoholic fatty liver disease (NAFLD is now the most common liver disease in the world. NAFLD can progress to nonalcoholic steatohepatitis (NASH, cirrhosis and eventually hepatocellular carcinoma. Acquired hepatic iron overload is seen in a number of patients with NAFLD; however, its significance in the pathology of NAFLD is still debated. Here, we investigated the role of dietary iron supplementation in experimental steatohepatitis in rats. Rats were fed a control, high-fat (HF, high-fat high-iron (HFHI and high-iron (HI diet for 30 weeks. Blood biochemical, histopathological and gut microbiota analyses were performed. Rats in HF and HFHI groups showed an ALT-dominant elevation of serum transaminases, hepatic steatosis, hepatic inflammation, and upregulation of proinflammatory cytokines. The number of large inflammatory foci, corresponding to lobular inflammation in NASH patients, was significantly higher in HFHI than in HF group; within the lesion, macrophages with intense iron staining were observed. Hepatic expression of TNFα was higher in HFHI than that in HF group. There was no significant change in hepatic oxidative stress, gut microbiota or serum endotoxin levels between HF and HFHI groups. These results suggested that dietary iron supplementation enhances experimental steatohepatitis induced by long-term high-fat diet feeding in rats. Iron-laden macrophages can play an important role in the enhancement of hepatic inflammation.

Stimulation of NADH-dependent microsomal DNA strand cleavage by rifamycin SV.

Science.gov (United States)

Kukiełka, E; Cederbaum, A I

1995-04-15

Rifamycin SV is an antibiotic anti-bacterial agent used in the treatment of tuberculosis. This drug can autoxidize, especially in the presence of metals, and generate reactive oxygen species. A previous study indicated that rifamycin SV can increase NADH-dependent microsomal production of reactive oxygen species. The current study evaluated the ability of rifamycin SV to interact with iron and increase microsomal production of hydroxyl radical, as detected by conversion of supercoiled plasmid DNA into the relaxed open circular state. The plasmid used was pBluescript II KS(-), and the forms of DNA were separated by agarose-gel electrophoresis. Incubation of rat liver microsomes with plasmid plus NADH plus ferric-ATP caused DNA strand cleavage. The addition of rifamycin SV produced a time- and concentration-dependent increase in DNA-strand cleavage. No stimulation by rifamycin SV occurred in the absence of microsomes, NADH or ferric-ATP. Stimulation occurred with other ferric complexes besides ferric-ATP, e.g. ferric-histidine, ferric-citrate, ferric-EDTA, and ferric-(NH4)2SO4. Rifamycin SV did not significantly increase the high rates of DNA strand cleavage found with NADPH as the microsomal reductant. The stimulation of NADH-dependent microsomal DNA strand cleavage was completely blocked by catalase, superoxide dismutase, GSH and a variety of hydroxyl-radical-scavenging agents, but not by anti-oxidants that prevent microsomal lipid peroxidation. Redox cycling agents, such as menadione and paraquat, in contrast with rifamycin SV, stimulated the NADPH-dependent reaction; menadione and rifamycin SV were superior to paraquat in stimulating the NADH-dependent reaction. These results indicate that rifamycin SV can, in the presence of an iron catalyst, increase microsomal production of reactive oxygen species which can cause DNA-strand cleavage. In contrast with other redox cycling agents, the stimulation by rifamycin SV is more pronounced with NADH than with NADPH as the

The Metabolism of Separase Inhibitor Sepin-1 in Human, Mouse, and Rat Liver Microsomes

Directory of Open Access Journals (Sweden)

Feng Li

2018-05-01

Full Text Available Separase, a known oncogene, is widely overexpressed in numerous human tumors of breast, bone, brain, blood, and prostate. Separase is an emerging target for cancer therapy, and separase enzymatic inhibitors such as sepin-1 are currently being developed to treat separase-overexpressed tumors. Drug metabolism plays a critical role in the efficacy and safety of drug development, as well as possible drug–drug interactions. In this study, we investigated the in vitro metabolism of sepin-1 in human, mouse, and rat liver microsomes (RLM using metabolomic approaches. In human liver microsomes (HLM, we identified seven metabolites including one cysteine–sepin-1 adduct and one glutathione–sepin-1 adduct. All the sepin-1 metabolites in HLM were also found in both mouse and RLM. Using recombinant CYP450 isoenzymes, we demonstrated that multiple enzymes contributed to the metabolism of sepin-1, including CYP2D6 and CYP3A4 as the major metabolizing enzymes. Inhibitory effects of sepin-1 on seven major CYP450s were also evaluated using the corresponding substrates recommended by the US Food and Drug Administration. Our studies indicated that sepin-1 moderately inhibits CYP1A2, CYP2C19, and CYP3A4 with IC50 < 10 μM but weakly inhibits CYP2B6, CYP2C8/9, and CYP2D6 with IC50 > 10 μM. This information can be used to optimize the structures of sepin-1 for more suitable pharmacological properties and to predict the possible sepin-1 interactions with other chemotherapeutic drugs.

Microsomal receptor for steroid hormones: functional implications for nuclear activity.

Science.gov (United States)

Muldoon, T G; Watson, G H; Evans, A C; Steinsapir, J

1988-01-01

Target tissues for steroid hormones are responsive by virtue of and to the extent of their content of functional intracellular receptors. Recent years have seen a shift in considerations of the cellular dynamics and distribution of these receptors, with current views favoring predominant intranuclear localization in the intact cell. This paper summarizes our analyses of the microsomal estrogen and androgen binding capability of rat uterine and ventral prostate tissue, respectively; these studies have revealed a set of high affinity sites that may act as a conduit for estrogen traversing the cell en route to the nucleus. These sites have many properties in common with cytosolic receptors, with the salient difference of a failure to activate to a more avid DNA-binding form under conditions which permit such activation of cytosolic receptors. The microsomal estrogen-binding proteins also have appreciable affinity for progesterone, another distinction from other known cellular estrogen receptor species. Various experimental approaches were employed to demonstrate that the microsomal receptors were not simply cytosol contaminants; the most convincing evidence is the recent successful separation of the cytosolic and microsomal forms by differential ammonium sulfate precipitation. Discrete subfractionation of subcellular components on successive sucrose gradients, with simultaneous assessments of binding capability and marker enzyme concentrations, indicates that the major portion of the binding is localized within the vesicles of the endoplasmic reticulum free of significant plasma membrane contamination. The microsomal receptors are readily solubilized by extraction with high- or low-salt-containing buffers or with steroid. The residual microsomes following such extraction have the characteristics of saturable acceptor sites for cytosolic estrogen-receptor complexes. The extent to which these sites will accept the cytosolic complexes is equal to the concentration of

In vitro metabolism of benzo[a]pyrene-7,8-dihydrodiol and dibenzo[def,p]chrysene-11,12 diol in rodent and human hepatic microsomes

Energy Technology Data Exchange (ETDEWEB)

Smith, Jordan N.; Mehinagic, Denis; Nag, Subhasree; Crowell, Susan R.; Corley, Richard A.

2017-03-01

Polycyclic aromatic hydrocarbons (PAHs) are contaminants that are ubiquitously found in the environment, produced through combustion of organic matter or petrochemicals, and many of which are procarcinogens. The prototypic PAH, benzo[a]pyrene (B[a]P) and the highly carcinogenic dibenzo[def,p]chrysene (DBC) are metabolically activated by isoforms of the P450 enzyme superfamily producing benzo[a]pyrene-7,8-dihydrodiol (B[a]P diol), dibenzo[def,p]chrysene-11,12 diol (DBC diol). Each of these diols can be further metabolized by cytochrome P450 enzymes to highly reactive diol-epoxide metabolites that readily react with DNA or by phase II conjugation facilitating excretion. To complement prior in vitro metabolism studies with parent B[a]P and DBC, both phase I metabolism and phase II glucuronidation of B[a]P diol and DBC diol were measured in hepatic microsomes from female B6129SF1/J mice, male Sprague-Dawley rats, and female humans. Metabolic parameters, including intrinsic clearance and Michaelis-Menten kinetics were calculated from substrate depletion data. Mice and rats demonstrated similar B[a]P diol phase I metabolic rates. Compared to rodents, human phase I metabolism of B[a]P diol demonstrated lower overall metabolic capacity, lower intrinsic clearance at higher substrate concentrations (>0.14 µM), and higher intrinsic clearance at lower substrate concentrations (<0.07 µM). Rates of DBC diol metabolism did not saturate in mice or humans and were highest overall in mice. Higher affinity constants and lower capacities were observed for DBC diol glucuronidation compared to B[a]P diol glucuronidation; however, intrinsic clearance values for these compounds were consistent within each species. Kinetic parameters reported here will be used to extend physiologically based pharmacokinetic (PBPK) models to include the disposition of B[a]P and DBC metabolites in animal models and humans to support future human health risk assessments.

ROLE OF LEPTIN ON CYTOCHROME P-450 AND SOME LIVER MICROSOMAL ENZYMES ACTIVITIES IN THE OBESE AND LEAN MICE

International Nuclear Information System (INIS)

HEBEISHY, M.I.A.; MAZEN, G.M.A.; SHAHIN, M.I

2008-01-01

Leptin is a hormone that is secreted by adipocytes and regulates body weight through its effect on satiety and energy metabolism. The obese mouse is deficient in this protein and is characterized by obesity and other metabolic disorders. This study investigated the alterations of several hepatic cytochrome P 4 -5 0 (CYP), conjugation and antioxidant enzymes in lean and obese mice and the role of leptin in the modulation of these enzymes. Lean and obese male mice were injected with leptin (100 μg / rat) for 15 days. The obtained results revealed that administration of leptin to lean mice caused a significant elevation in the level of blood glucose, serum insulin, 6α, 6β, 16α- hydroxylation of testosterone, the activity of CYP 1 A 1 , CYP 4 A and GSH reductase in liver microsomes while serum corticosterone and the activity of total GSH were significantly decreased when compared to lean control mice. Moreover, obese mice treated with leptin recorded significant reduction in body weight, blood glucose concentration, serum levels of insulin and corticosterone, 7α and 16α- hydroxylation of testosterone, the activity of CYP 1A 1, CYP 2 B 1 and CYP 4 A and GST in liver microsomes. On the other hand, 6α, 6β-hydroxylation of testosterone, the activity of CYP 2 E 1 and GSH reductase in liver microsome were significantly increased when compared to obese control mice. The mechanism for the observed alterations may be due to direct leptin effects or via indirect alterations in insulin, corticosterone and/or growth hormone

The in vitro NADPH-dependent inhibition by CCl4 of the ATP-dependent calcium uptake of hepatic microsomes from male rats. Studies on the mechanism of the inactivation of the hepatic microsomal calcium pump by the CCl3 radical

International Nuclear Information System (INIS)

Srivastava, S.P.; Chen, N.Q.; Holtzman, J.L.

1990-01-01

The hepatotoxicity of CCl4 is mediated through its initial reduction by cytochrome P-450 to the CCl3 radical. This radical then damages important metabolic systems such as the ATP-dependent microsomal Ca2+ pump. Previous studies from our laboratory on isolated microsomes have shown that NADPH in the absence of toxic agents inhibits this pump. We have now found in in vitro incubations that CCl4 (0.5-2.5 mM) enhanced the NADPH-dependent inhibition of Ca2+ uptake from 28% without CCl4 to a maximum of 68%. These concentrations are in the range found in the livers and blood of lethally intoxicated animals and are toxic to cultured hepatocytes. The inhibition of Ca2+ uptake was due both to a decrease in the Ca2(+)-dependent ATPase and to an enhanced release of Ca2+ from the microsomes. The NADPH-dependent CCl4 inhibition was greater under N2 and was totally prevented by CO. GSH (1-10 mM) added during the incubation with CCl4 prevented the inhibition. This protection was also seen when the incubations were performed under nitrogen. When samples were preincubated with CCl4, the CCl4 metabolism was stopped, and then the Ca2+ uptake was determined; GSH reversed the CCl4 inhibition of Ca2+ uptake. This reversal showed saturation kinetics for GSH with two Km values of 0.315 and 93 microM when both the preincubation and the Ca2+ uptake were performed under air, and 0.512 and 31 microM when both were performed under nitrogen. Cysteine did not prevent the NADPH-dependent CCl4 inhibition of Ca2+ uptake. CCl4 increased lipid peroxidation in air, but no lipid peroxidation was seen under nitrogen. Lipid peroxidation was only modestly reversed by GSH. GSH did not remove 14C bound to samples preincubated with the 14CCl4

Perfluorooctane Sulfonate-Induced Hepatic Steatosis in Male Sprague Dawley Rats Is Not Attenuated by Dietary Choline Supplementation.

Science.gov (United States)

Bagley, Bradford D; Chang, Shu-Ching; Ehresman, David J; Eveland, Alan; Zitzow, Jeremiah D; Parker, George A; Peters, Jeffrey M; Wallace, Kendall B; Butenhoff, John L

2017-12-01

Perfluorooctane sulfonate (PFOS) is an environmentally persistent chemical. Dietary 100 ppm PFOS fed to male mice and rats for 4 weeks caused hepatic steatosis through an unknown mechanism. Choline deficient diets can cause hepatic steatosis. A hepatic choline:PFOS ion complex was hypothesized to cause this effect in mice. This study tested whether dietary choline supplementation attenuates PFOS-induced hepatic steatosis in rats. Sprague Dawley rats (12/sex/group) were fed control, choline supplemented (CS), 100 ppm PFOS, or 100 ppm PFOS + CS diets for 3 weeks. Male rats fed both PFOS-containing diets had decreased serum cholesterol and triglycerides (TGs) on days 9, 16, and/or 23 and increased hepatic free fatty acids and TG (ie, steatosis). Female rats fed both PFOS diets had decreased serum cholesterol on days 9 and 16 and decreased hepatic free fatty acid and TG at termination (ie, no steatosis). Liver PFOS concentrations were similar for both sexes. Liver choline concentrations were increased in male rats fed PFOS (±CS), but the increase was lower in the PFOS + CS group. Female liver choline concentrations were not altered by any diet. These findings demonstrate a clear sex-related difference in PFOS-induced hepatic steatosis in the rat. Additional evaluated mechanisms (ie, nuclear receptor activation, mRNA upregulation, and choline kinase activity inhibition) did not appear to be involved in the hepatic steatosis. Dietary PFOS (100 ppm) induced hepatic steatosis in male, but not female, rats that was not attenuated by choline supplementation. The mechanism of lipid accumulation and the sex-related differences warrant further investigation. © The Author 2017. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

IMMUNOHISTOCHEMICAL STUDY OF EXTRACELLULAR-MATRIX IN ACUTE GALACTOSAMINE HEPATITIS IN RATS

NARCIS (Netherlands)

JONKER, AM; DIJKHUIS, FWJ; BOES, A; HARDONK, MJ

A single injection of D-galactosamine hydrochloride induces acute self-limiting liver disease in rats that morphologically resembles drug-induced hepatitis in human beings. In this immunohistochemical study we examined the localization and expression of the hepatic extracellular matrix components

Hepatitis B virus e antigen induces activation of rat hepatic stellate cells

International Nuclear Information System (INIS)

Zan, Yanlu; Zhang, Yuxia; Tien, Po

2013-01-01

Highlights: •HBeAg expression in HSCs induced production of ECM protein and liver fibrotic markers. •The activation and proliferation of HSCs were mediated by TGF-β. •HBeAg protein purified from cell medium directly activated HSCs. -- Abstract: Chronic hepatitis B virus infection is a major cause of hepatic fibrosis, leading to liver cirrhosis and hepatocellular carcinoma. Hepatitis B virus e antigen (HBeAg) is an accessory protein of HBV, not required for viral replication but important for natural infection in vivo. Hepatic stellate cells (HSCs) are the major producers of excessive extracellular matrix during liver fibrogenesis. Therefore, we examined the influence of HBeAg on HSCs. The rat HSC line HSC-T6 was transfected with HBeAg plasmids, and expression of α-smooth muscle actin, collagen I, transforming growth factor-β1 (TGF-β), and tissue inhibitors of metalloproteinase 1 (TIMP-1) was investigated by quantitative real-time PCR. The proliferation of HSCs was determined by MTS analysis. HBeAg transduction induced up-regulation of these fibrogenic genes and proliferation of HSCs. We found that HBeAg induced TGF-β secretion in HSCs, and the activation of HSCs was prevented by a neutralizing anti-TGF-β antibody. Depletion and addition of HBeAg protein in conditioned medium from HSC-T6 cells transduced with HBeAg indicated that HBeAg directly induced the activation and proliferation of rat primary HSCs. Taken together, HBeAg induces the activation and proliferation of HSCs, mainly mediated by TGF-β, and HBeAg protein purified from cell medium can directly activate HSCs

Hepatitis B virus e antigen induces activation of rat hepatic stellate cells

Energy Technology Data Exchange (ETDEWEB)

Zan, Yanlu [Center for Molecular Virology, CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Zhang, Yuxia, E-mail: yzhang@wehi.edu.au [Center for Molecular Virology, CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101 (China); Tien, Po, E-mail: tienpo@sun.im.ac.cn [Center for Molecular Virology, CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101 (China)

2013-06-07

Highlights: •HBeAg expression in HSCs induced production of ECM protein and liver fibrotic markers. •The activation and proliferation of HSCs were mediated by TGF-β. •HBeAg protein purified from cell medium directly activated HSCs. -- Abstract: Chronic hepatitis B virus infection is a major cause of hepatic fibrosis, leading to liver cirrhosis and hepatocellular carcinoma. Hepatitis B virus e antigen (HBeAg) is an accessory protein of HBV, not required for viral replication but important for natural infection in vivo. Hepatic stellate cells (HSCs) are the major producers of excessive extracellular matrix during liver fibrogenesis. Therefore, we examined the influence of HBeAg on HSCs. The rat HSC line HSC-T6 was transfected with HBeAg plasmids, and expression of α-smooth muscle actin, collagen I, transforming growth factor-β1 (TGF-β), and tissue inhibitors of metalloproteinase 1 (TIMP-1) was investigated by quantitative real-time PCR. The proliferation of HSCs was determined by MTS analysis. HBeAg transduction induced up-regulation of these fibrogenic genes and proliferation of HSCs. We found that HBeAg induced TGF-β secretion in HSCs, and the activation of HSCs was prevented by a neutralizing anti-TGF-β antibody. Depletion and addition of HBeAg protein in conditioned medium from HSC-T6 cells transduced with HBeAg indicated that HBeAg directly induced the activation and proliferation of rat primary HSCs. Taken together, HBeAg induces the activation and proliferation of HSCs, mainly mediated by TGF-β, and HBeAg protein purified from cell medium can directly activate HSCs.

PPARα ligands activate antioxidant enzymes and suppress hepatic fibrosis in rats

International Nuclear Information System (INIS)

Toyama, Tetsuya; Nakamura, Hideki; Harano, Yuichi; Yamauchi, Norihito; Morita, Atsuhiro; Kirishima, Toshihiko; Minami, Masahito; Itoh, Yoshito; Okanoue, Takeshi

2004-01-01

Oxidative stress is a major pathogenetic factor in hepatic fibrosis. Peroxisome proliferator-activated receptor α (PPARα) is a nuclear receptor which is known to affect oxidative stress and PPARα ligands may have rescue effects on hepatic fibrosis. We tested this hypothesis using rat thioacetamide (TAA) models of liver cirrhosis. Rats were given intraperitoneal injection of TAA and treated with a diet containing one of the two PPARα ligands, Wy-14,643 (WY) or fenofibrate. WY treatment dramatically reduced hepatic fibrosis and also prevented the inhibition catalase of mRNA expression caused by TAA. Correspondingly, catalase activity increased in the TAA + WY group but decreased in the control TAA group. The antifibrotic action of fenofibrate in the TAA model was comparable with that of WY. PPARα ligands have an antifibrotic action in the rat TAA model of liver cirrhosis, probably due to an antioxidant effect of enhanced catalase expression and activity in the liver

Mitochondria-targeted antioxidant mitoquinone deactivates human and rat hepatic stellate cells and reduces portal hypertension in cirrhotic rats.

Science.gov (United States)

Vilaseca, Marina; García-Calderó, Héctor; Lafoz, Erica; Ruart, Maria; López-Sanjurjo, Cristina Isabel; Murphy, Michael P; Deulofeu, Ramon; Bosch, Jaume; Hernández-Gea, Virginia; Gracia-Sancho, Jordi; García-Pagán, Juan Carlos

2017-07-01

In cirrhosis, activated hepatic stellate cells (HSC) play a major role in increasing intrahepatic vascular resistance and developing portal hypertension. We have shown that cirrhotic livers have increased reactive oxygen species (ROS), and that antioxidant therapy decreases portal pressure. Considering that mitochondria produce many of these ROS, our aim was to assess the effects of the oral mitochondria-targeted antioxidant mitoquinone on hepatic oxidative stress, HSC phenotype, liver fibrosis and portal hypertension. Ex vivo: Hepatic stellate cells phenotype was analysed in human precision-cut liver slices in response to mitoquinone or vehicle. In vitro: Mitochondrial oxidative stress was analysed in different cell type of livers from control and cirrhotic rats. HSC phenotype, proliferation and viability were assessed in LX2, and in primary human and rat HSC treated with mitoquinone or vehicle. In vivo: CCl 4 - and thioacetamide-cirrhotic rats were treated with mitoquinone (5 mg/kg/day) or the vehicle compound, DecylTPP, for 2 weeks, followed by measurement of oxidative stress, systemic and hepatic haemodynamic, liver fibrosis, HSC phenotype and liver inflammation. Mitoquinone deactivated human and rat HSC, decreased their proliferation but with no effects on viability. In CCl 4 -cirrhotic rats, mitoquinone decreased hepatic oxidative stress, improved HSC phenotype, reduced intrahepatic vascular resistance and diminished liver fibrosis. These effects were associated with a significant reduction in portal pressure without changes in arterial pressure. These results were further confirmed in the thioacetamide-cirrhotic model. We propose mitochondria-targeted antioxidants as a novel treatment approach against portal hypertension and cirrhosis. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Vitamin B12 supplement alleviates N'-nitrosodimethylamine-induced hepatic fibrosis in rats.

Science.gov (United States)

Ahmad, Areeba; Afroz, Nishat; Gupta, Umesh D; Ahmad, Riaz

2014-01-10

Abstract Context: Altered vitamin B 12 levels have been correlated with hepatotoxicity; however, further evidence is required to establish its protective role. Objective: To evaluate the effects of vitamin B 12 supplement in protecting N'-nitrosodimethylamine (NDMA)-induced hepatic fibrosis in Wistar rats. Materials and methods: Hepatic fibrosis was induced by administering NDMA in doses of 10 mg/kg body weight thrice a week for 21 days. Another group received equal doses (10 mg/kg body weight) of vitamin B 12 subsequent to NDMA treatment. Animals from either group were sacrificed weekly from the start of the treatment along with their respective controls. Progression of hepatic fibrosis, in addition to the effect of vitamin B 12 , was assessed biochemically for liver function biomarkers, liver glycogen, hydroxyproline (HP) and B 12 reserves along with histopathologically by hematoxylin and eosin (H & E) as well immunohistochemical staining for α-SMA expression. Results and discussion: Elevation in the levels of aminotransferases, SALP, total bilirubin and HP was observed in NDMA treated rats, which was concomitant with remarkable depletion in liver glycogen and B 12 reserves (p < 0.05). Liver biopsies also demonstrated disrupted lobular architecture, collagen amassing and intense fibrosis by NDMA treatment. Immunohistochemical staining showed the presence of activated stellate cells that was dramatically increased up to day 21 in fibrotic rats. Following vitamin B 12 treatment, liver function biomarkers, glycogen contents and hepatic vitamin B 12 reserves were restored in fibrotic rats, significantly. Vitamin B 12 administration also facilitated restoration of normal liver architecture. Conclusion: These findings provide interesting new evidence in favor of protective role for vitamin B 12 against NDMA-induced hepatic fibrosis in rats.

An iron-deficient diet stimulates the onset of the hepatitis due to hepatic copper deposition in the Long-Evans Cinnamon (LEC) rat

Energy Technology Data Exchange (ETDEWEB)

Sugawara, Naoki; Sugawara, Chieko [Sapporo Medical Univ. (Japan). Dept. of Public Health

1999-09-01

To study effects of dietary Cu and Fe levels on the onset of hepatitis in Long-Evans Cinnamon (LEC) rats, female rats (40 days old) were fed a semipurified diet containing 0.1 or 10 mg Cu/kg and 1.5 or 150 mg Fe/kg in a 2 x 2 factorial arrangement for 35 days. At 75 days after birth, LEC rats (+Cu-Fe) fed a Cu-sufficient but Fe-deficient diet (Cu, 10 mg/kg; Fe, 1.5 mg/kg) showed jaundice, with lethargy, anorexia, and malaise. The biochemical variables relating to liver function were significantly increased compared to three other groups, a Cu- and Fe-deficient (-Cu-Fe) group, a Cu-deficient but Fe-sufficient (-Cu+Fe) group, and a Cu and Fe sufficient (+Cu+Fe) group. Furthermore, the +Cu-Fe rat liver showed massive necrosis with huge nuclei. The other three groups presented no biochemical and histological findings of hepatitis. Hepatic Cu and metallothionein concentrations were 289 {+-} 87 (mean {+-} SD) {mu}g/g liver and 8.7 {+-} 1.8 mg/g liver, respectively, in the +Cu-Fe rats. However, in the +Cu+Fe group the values were 196 {+-} 28 {mu}g Cu/g liver and 10.8 {+-} 1.0 mg/g liver. Hepatic Fe deposition was not influenced significantly by the dietary Cu level. The +Cu-Fe group with jaundice showed the highest free Cu concentration in the liver among the four groups, but the hepatic free Fe concentration was similar to those in the -Cu+Fe and +Cu+Fe groups. Our results indicate that an Fe-deficient diet enhances the deposition of hepatic Cu due to increased absorption of Cu from the gastrointestinal tract. This deposition stimulated the onset of hepatitis. (orig.)

Lipid peroxidation in microsomes of murine bone marrow after low-dose γ-irradiation

International Nuclear Information System (INIS)

Schwenke, K.; Coslar, S.; Muehlensiepen, H.; Altman, K.I.; Feinendegen, L.E.

1994-01-01

The principal aim of the study was to investigate the effect of low-dose γ-irradiation on lipid peroxidation (LPO) in murine bone marrow. To this end, the degree of LPO in suspensions of microsomes of murine bone marrow cells (BMC) was determined in terms of malondialdehyde (MDA) formation after whole-body or in vitro exposure to various doses of γ-radiation. These effects were compared to some extent with similar effects in liver and spleen preparations. As to the effect of γ-irradiation on LPO in BMC, the response depends on the dose level and on whether whole-body or in vitro exposures are involved. Whole-body irradiation did not result in an increase in LPO in BMC microsomes, even at such high doses as 15 Gy, although hepatic microsomes showed a marked increase. In contrast, in vitro irradiation of BMC microsomes with 0.1, 10 and 50 Gy brought about an increase in LPO. This increase was already significant (P < 0.05) at 0.1 Gy following a post-irradiation incubation and substantial at 50 Gy, even without subsequent incubation. The results show that low doses of γ-irradiation are able to induce an elevation of LPO in murine BMC microsomes, but only after in vitro irradiation. In the case of whole-body irradiation cellular radical scavengers and other metabolic reactions may prevent a measurable increase in LPO. This is partly illustrated by the case of vitamin-E deficiency, where a substantial increase in LPO in BMC microsomes is observed even without γ-irradiation in comparison with euvitaminotic mice because normally occurring radicals are not scavenged sufficiently. (orig.)

A novel assay for detecting antibodies to cytochrome P4502D6, the molecular target of liver kidney microsomal antibody type 1.

Science.gov (United States)

Kerkar, N; Ma, Y; Hussain, M; Muratori, L; Targett, C; Williams, R; Bianchi, F B; Mieli-Vergani, G; Vergani, D

1999-03-04

Liver Kidney Microsomal type 1 (LKM1) antibody, the diagnostic marker of autoimmune hepatitis type 2, is also found in a proportion of patients with hepatitis C virus infection (HCV). It is detected conventionally by the subjective immunofluorescence technique. Our aim was to establish a simple and objective enzyme-linked immunosorbent assay (ELISA) that measures antibodies to cytochrome P4502D6 (CYP2D6), the target of LKM1. An indirect ELISA using eukaryotically expressed CYP2D6 was designed. Absorbance values obtained against a reference microsomal preparation were subtracted from those obtained against a microsomal preparation over-expressing CYP2D6, thus removing the non-CYP2D6-specific reaction. Sera from 51 LKM1 positive patients (21 autoimmune hepatitis and 30 with HCV infection), 111 LKM1 negative patients with chronic liver disease (including 20 with HCV infection) and 43 healthy controls were tested. Of 51 patients positive by immunofluorescence, 48 were also positive by ELISA while all the 154 LKM1 negative subjects were also negative by ELISA. There was a high degree of association between IFL and ELISA as demonstrated by a kappa reliability value of 0.96. The absorbance values by ELISA correlated with immunofluorescence LKM1 titres both in autoimmune hepatitis (r = 0.74, p < 0.001) and HCV infection (r = 0.67, p < 0.001). The simple, objective ELISA described has the potential to replace the standard immunofluorescence technique.

Exercise training modulates the hepatic renin-angiotensin system in fructose-fed rats.

Science.gov (United States)

Frantz, Eliete Dalla Corte; Medeiros, Renata Frauches; Giori, Isabele Gomes; Lima, Juliana Bittencourt Silveira; Bento-Bernardes, Thais; Gaique, Thaiane Gadioli; Fernandes-Santos, Caroline; Fernandes, Tiago; Oliveira, Edilamar Menezes; Vieira, Carla Paulo; Conte-Junior, Carlos Adam; Oliveira, Karen Jesus; Nobrega, Antonio Claudio Lucas

2017-09-01

What is the central question of this study? What are the effects of exercise training on the hepatic renin-angiotensin system and their contribution to damage resulting from fructose overload in rats? What is the main finding and its importance? Exercise training attenuated the deleterious actions of the angiotensin-converting enzyme/angiotensin II/angiotensin II type 1 receptor axis and increased expression of the counter-regulatory (angiotensin-converting enzyme 2/angiotensin (1-7)/Mas receptor) axis in the liver. Therefore, our study provides evidence that exercise training modulates the hepatic renin-angiotensin system, which contributes to reducing the progression of metabolic dysfunction and non-alcoholic fatty liver disease in fructose-fed rats. The renin-angiotensin system (RAS) has been implicated in the development of metabolic syndrome. We investigated whether the hepatic RAS is modulated by exercise training and whether this modulation improves the deleterious effects of fructose overload in rats. Male Wistar rats were divided into (n = 8 each) control (CT), exercise control (CT-Ex), high-fructose (HFr) and exercise high-fructose (HFr-Ex) groups. Fructose-drinking rats received d-fructose (100 g l -1 ). After 2 weeks, CT-Ex and HFr-Ex rats were assigned to a treadmill training protocol at moderate intensity for 8 weeks (60 min day -1 , 4 days per week). We assessed body mass, glucose and lipid metabolism, hepatic histopathology, angiotensin-converting enzyme (ACE) and angiotensin-converting enzyme 2 (ACE2) activity, the angiotensin concentration and the expression profile of proteins affecting the hepatic RAS, gluconeogenesis and inflammation. Neither fructose overload nor exercise training influenced body mass gain and serum ACE and ACE2 activity. The HFr group showed hyperinsulinaemia, but exercise training normalized this parameter. Exercise training was effective in preventing hepatic steatosis and in preventing triacylglycerol and

Modulation of gut microbiota contributes to curcumin-mediated attenuation of hepatic steatosis in rats.

Science.gov (United States)

Feng, Wenhuan; Wang, Hongdong; Zhang, Pengzi; Gao, Caixia; Tao, Junxian; Ge, Zhijuan; Zhu, Dalong; Bi, Yan

2017-07-01

Structural disruption of gut microbiota contributes to the development of non-alcoholic fatty liver disease (NAFLD) and modulating the gut microbiota represents a novel strategy for NAFLD prevention. Although previous studies have demonstrated that curcumin alleviates hepatic steatosis, its effect on the gut microbiota modulation has not been investigated. Next generation sequencing and multivariate analysis were utilized to evaluate the structural changes of gut microbiota in a NAFLD rat model induced by high fat-diet (HFD) feeding. We found that curcumin attenuated hepatic ectopic fat deposition, improved intestinal barrier integrity, and alleviated metabolic endotoxemia in HFD-fed rats. More importantly, curcumin dramatically shifted the overall structure of the HFD-disrupted gut microbiota toward that of lean rats fed a normal diet and altered the gut microbial composition. The abundances of 110 operational taxonomic units (OTUs) were altered by curcumin. Seventy-six altered OTUs were significantly correlated with one or more hepatic steatosis associated parameters and designated 'functionally relevant phylotypes'. Thirty-six of the 47 functionally relevant OTUs that were positively correlated with hepatic steatosis associated parameters were reduced by curcumin. These results indicate that curcumin alleviates hepatic steatosis in part through stain-specific impacts on hepatic steatosis associated phylotypes of gut microbiota in rats. Compounds with antimicrobial activities should be further investigated as novel adjunctive therapies for NAFLD. Copyright © 2017 Elsevier B.V. All rights reserved.

Antibodies against human cytochrome P-450db1 in autoimmune hepatitis type II.

OpenAIRE

Zanger, U M; Hauri, H P; Loeper, J; Homberg, J C; Meyer, U A

1988-01-01

In a subgroup of children with chronic active hepatitis, circulating autoantibodies occur that bind to liver and kidney endoplasmic reticulum (anti-liver/kidney microsome antibody type I or anti-LKM1). Anti-LKM1 titers follow the severity of the disease and the presence of these antibodies serves as a diagnostic marker for this autoimmune hepatitis type II. We demonstrate that anti-LKM1 IgGs specifically inhibit the hydroxylation of bufuralol in human liver microsomes. Using two assay systems...

Anti-liver-kidney microsome antibody type 1 recognizes human cytochrome P450 db1.

Science.gov (United States)

Gueguen, M; Yamamoto, A M; Bernard, O; Alvarez, F

1989-03-15

Anti-liver-kidney microsome antibody type 1 (LKM1), present in the sera of a group of children with autoimmune hepatitis, was recently shown to recognize a 50 kDa protein identified as rat liver cytochromes P450 db1 and db2. High homology between these two members of the rat P450 IID subfamily and human P450 db1 suggested that anti-LKM1 antibody is directed against this human protein. To test this hypothesis, a human liver cDNA expression library in phage lambda GT-11 was screened using rat P450 db1 cDNA as a probe. Two human cDNA clones were found to be identical to human P450 db1 by restriction mapping. Immunoblot analysis using as antigen, the purified fusion protein from one of the human cDNA clones showed that only anti-LKM1 with anti-50 kDa reactivity recognized the fusion protein. This fusion protein was further used to develop an ELISA test that was shown to be specific for sera of children with this disease. These results: 1) identify the human liver antigen recognized by anti-LKM1 auto-antibodies as cytochrome P450 db1, 2) allow to speculate that mutation on the human P450 db1 gene could alter its expression in the hepatocyte and make it auto-antigenic, 3) provide a simple and specific diagnostic test for this disease.

Hepatic drug clearance following traumatic injury.

Science.gov (United States)

Slaughter, R L; Hassett, J M

1985-11-01

Trauma is a complex disease state associated with physiologic changes that have the potential to alter hepatic drug clearance mechanisms. These responses include alterations in hepatic blood flow, reduction in hepatic microsomal activity, reduction in hepatic excretion processes, and changes in protein binding. Hepatic blood flow is influenced by sympathomimetic activity. Both animal and human studies demonstrate an initial reduction and subsequent increase in hepatic blood flow, which coincides with an observed increase and subsequent return to normal in serum catecholamine concentrations. Unfortunately, there are no human studies that address the importance these findings may have to the clearance processes of high intrinsic clearance compounds. Animal studies of trauma indicate that hepatic microsomal activity is depressed during the post-traumatic period. Reduction in the hepatic clearance of antipyrine, a model low intrinsic compound, has also been demonstrated in animal models of trauma. In addition to these effects, hepatic excretion of substances such as indocyanine green and bilirubin have been demonstrated to be impaired in both traumatized animals and humans. Finally, substantial increases in the serum concentration of the binding protein alpha 1-acid glycoprotein occur in trauma patients. This has been reported to be associated with subsequent decreases in the free fraction of lidocaine and quinidine. In addition to changing serum drug concentration/response relationships, the pharmacokinetic behavior of drugs bound to alpha 1-acid glycoprotein should also change. Preliminary observations in our laboratory in a dog model of surgically-induced trauma have shown a reduction in the total clearance of lidocaine and reduction in free lidocaine concentration.(ABSTRACT TRUNCATED AT 250 WORDS)

Increased hepatic glycogen synthetase and decreased phosphorylase in trained rats

DEFF Research Database (Denmark)

Galbo, H; Saugmann, P; Richter, Erik

1979-01-01

Rats were either physically trained by a 12 wk swimming program or were freely eating or weight matched, sedentary controls. Trained rats had a higher relative liver weight and total hepatic glycogen synthetase (EC 2.4.1.11) activity and a lower phosphorylase (EC 2.4.1.1) activity than the other...

Effect of ethylene glycol monomethyl ether and diethylene glycol monomethyl ether on hepatic metabolizing enzymes.

Science.gov (United States)

Kawamoto, T; Matsuno, K; Kayama, F; Hirai, M; Arashidani, K; Yoshikawa, M; Kodama, Y

1990-06-01

Glycol ethers have been extensively used in industry over the past 40-50 years. Numerous studies on the toxicity of glycol ethers have been performed, however, the effects of glycol ethers on the hepatic drug metabolizing enzymes are still unknown. We studied the changes of the putative metabolic enzymes, that is, the hepatic microsomal mixed function oxidase system and cytosolic alcohol dehydrogenase, by the oral administration of diEGME and EGME. Adult male Wistar rats were used. DiEGME was administered orally; 500, 1000, 2000 mg/kg for 1, 2, 5 or 20 days and EGME was 100, 300 mg/kg for 1, 2, 5 or 20 days. Decreases in liver weights were produced by highest doses of diEGME (2000 mg/kg body wt/day for 20 days) and EGME (300 mg/kg body wt/day for 20 days). DiEGME increased hepatic microsomal protein contents and induced cytochrome P-450, but not cytochrome b5 or NADPH-cytochrome c reductase. The activity of cytosolic ADH was not affected by diEGME administration. On the other hand, EGME did not change cytochrome P-450, cytochrome b5 or NADPH-cytochrome c reductase. The activity of cytosolic ADH was increased by repeated EGME treatment. Therefore it is suspected that the enzyme which takes part in the metabolism of diEGME is different from that of EGME, although diEGME is a structural homologue of EGME.

Protection of the Extracts of Lentinus edodes Mycelia against Carbon-Tetrachloride-Induced Hepatic Injury in Rats

Directory of Open Access Journals (Sweden)

Mei-Fen Chen

2012-01-01

Full Text Available Lentinus edodes is the medicinal macrofungus showing potential for therapeutic applications in infectious disorders including hepatitis. In an attempt to develop the agent for handling hepatic injury, we used the extracts of Lentinus edodes mycelia (LEM to screen the effect on hepatic injury in rats induced by carbon tetrachloride (CCl4. Intraperitoneal administration of CCl4 not only increased plasma glutamic oxaloacetic transaminase (GOT and glutamic pyruvic transaminase (GPT but also decreased hepatic superoxide dismutase (SOD and glutathione peroxidase (GPx levels in rats. Similar to the positive control silymarin, oral administration (three times daily of this product (LEM for 8 weeks significantly reduced plasma GOT and GPT. Also, the activities of antioxidant enzymes of SOD and GPx were elevated by LEM. in liver from CCl4-treated rats, indicating that mycelium can increase antioxidant-like activity. Moreover, the hepatic mRNA and protein levels of SOD and GPx were both markedly raised by LEM. The obtained results suggest that oral administration of the extracts of Lentinus edodes mycelia (LEM has the protective effect against CCl4-induced hepatic injury in rats, mainly due to an increase in antioxidant-like action.

Maraviroc attenuates trauma-hemorrhage-induced hepatic injury through PPAR gamma-dependent pathway in rats.

Directory of Open Access Journals (Sweden)

Fu-Chao Liu

Full Text Available Maraviroc is a CC-chemokine receptor 5 (CCR5 antagonist with potent antiviral and cancer preventive effects. Recent evidence suggests that the co-existence of CCR5 in various cell types is involved in inflammation. However, the effects that CCR5 antagonists produce in trauma-hemorrhage remain unknown. The peroxisome proliferator-activated receptor gamma (PPAR(γ pathway exerts anti-inflammatory effects in injury. In this study, we hypothesized that maraviroc administration in male rats, after trauma-hemorrhage, decreases cytokine production and protects against hepatic injury through a PPAR(γ-dependent pathway. Male Sprague-Dawley rats underwent trauma-hemorrhage (mean blood pressure maintained at approximately 35-40 mmHg for 90 minutes, followed by fluid resuscitation. During resuscitation, a single dose of maraviroc (3 mg/kg, intravenously with and without a PPAR(γ antagonist GW9662 (1 mg/kg, intravenously, GW9662 or vehicle was administered. Plasma alanine aminotransferase (ALT with aspartate aminotransferase (AST concentrations and various hepatic parameters were measured (n=8 rats/group at 24 hours after resuscitation. The results showed that trauma-hemorrhage increased hepatic myeloperoxidase activity, intercellular adhesion molecule-1 and interleukin-6 levels, and plasma ALT and AST concentrations. These parameters were significantly improved in the maraviroc-treated rats subjected to trauma-hemorrhage. Maraviroc treatment also increased hepatic PPAR(γ expression compared with vehicle-treated trauma-hemorrhaged rats. Co-administration of GW9662 with maraviroc abolished the maraviroc-induced beneficial effects on the above parameters and hepatic injury. These results suggest that the protective effect of maraviroc administration on alleviation of hepatic injury after trauma-hemorrhage, which is, at least in part, through PPAR(γ-dependent pathway.

Fenproporex N-dealkylation to amphetamine--enantioselective in vitro studies in human liver microsomes as well as enantioselective in vivo studies in Wistar and Dark Agouti rats.

Science.gov (United States)

Kraemer, Thomas; Pflugmann, Thomas; Bossmann, Michael; Kneller, Nicole M; Peters, Frank T; Paul, Liane D; Springer, Dietmar; Staack, Roland F; Maurer, Hans H

2004-09-01

Fenproporex (FP) is known to be N-dealkylated to R(-)-amphetamine (AM) and S(+)-amphetamine. Involvement of the polymorphic cytochrome P450 (CYP) isoform CYP2D6 in metabolism of such amphetamine precursors is discussed controversially in literature. In this study, the human hepatic CYPs involved in FP dealkylation were identified using recombinant CYPs and human liver microsomes (HLM). These studies revealed that not only CYP2D6 but also CYP1A2, CYP2B6 and CYP3A4 catalyzed this metabolic reaction for both enantiomers with slight preference for the S(+)-enantiomer. Formation of amphetamine was not significantly changed by quinidine and was not different in poor metabolizer HLM compared to pooled HLM. As in vivo experiments, blood levels of R(-)-amphetamine and S(+)-amphetamine formed after administration of FP were determined in female Dark Agouti rats (fDA), a model of the human CYP2D6 poor metabolizer phenotype (PM), male Dark Agouti rats (mDA), an intermediate model, and in male Wistar rats (WI), a model of the human CYP2D6 extensive metabolizer phenotype. Analysis of the plasma samples showed that fDA exhibited significantly higher plasma levels of both amphetamine enantiomers compared to those of WI. Corresponding plasma levels in mDA were between those in fDA and WI. Furthermore, pretreatment of WI with the CYP2D inhibitor quinine resulted in significantly higher amphetamine plasma levels, which did not significantly differ from those in fDA. The in vivo studies suggested that CYP2D6 is not crucial to the N-dealkylation but to another metabolic step, most probably to the ring hydroxylation. Further studies are necessary for elucidating the role of CYP2D6 in FP hydroxylation.

Inhibition of methylation of DNA by dimethylnitrosamine (DMN) in dehydroepiandrosterone-fed rats

International Nuclear Information System (INIS)

Prasanna, H.R.; Magee, P.N.; Harrington, G.W.; Hart, R.W.

1989-01-01

The influence of the anticarcinogen dehydroepiandrosterone (DHEA) on the metabolism and macromolecular interactions of the potent hepatocarcinogen dimethylnitrosamine (NDMA) was investigated. Male Sprague-Dawley rats (2-3 mo old) were fed DHEA for 14 d at a dietary level 0.8%. Compared with pair-fed controls, the liver weights of the DHEA-treated animals increased significantly (11.7 vs. 7.1 g) with increase, per total liver, in proteins including those of cytosol and microsomes as well as cytochromes P-450 and b 5 . DNA content of the liver, however, remained constant. Five hours after a single ip dose of [ 14 C]NDMA (30 mg/kg body wt, 42 μCi/rat) DNA methylation was reduced in the DHEA-fed animals as measured by 7-methyl- and O 6 -methylguanine per mole of guanine, by 39 and 31%, respectively. The rate of NDMA metabolism was slightly higher in the DHEA-fed rats as determine in vivo by the exhalation of 14 CO 2 and by the declining concentrations of NDMA in the blood. The incorporation of radioactivity from [ 14 C]NDMA into hepatic proteins in vivo was greater (2.1-fold) in the DHEA-fed rats. Our results suggest that feeding rats with the adrenal steroid DHEA enhances the metabolic activation of NDMA in vivo, and that the increased association of NDMA-derived metabolites with increased hepatic cellular proteins may be partially responsible for protection of hepatic DNA from NDMA-induced damage

Immunological cross-reactivity to multiple autoantigens in patients with liver kidney microsomal type 1 autoimmune hepatitis.

Science.gov (United States)

Choudhuri, K; Gregorio, G V; Mieli-Vergani, G; Vergani, D

1998-11-01

We describe two patients with liver kidney microsomal antibody type 1 (LKM1)-positive autoimmune hepatitis (AIH) with associated endocrinopathies. The first patient had insulin-dependent diabetes (IDDM), and the second patient had Addison's disease and hypoparathyroidism, and is also positive for islet cell antibodies, without overt diabetes. To account for the existence of multiple endocrinopathy in these patients, we investigated whether there is sequence similarity between the target of LKM1 antibodies, cytochrome P4502D6 (CYP2D6), and other human proteins, and if so, whether this structural similarity produces a detectable cross-reactive immune response. Our database search identified two proteins, carboxypeptidase H, an autoantigen in insulin-dependent diabetes, and 21-hydroxylase, the major autoantigen in Addison's disease, that share sequence similarity to the second major LKM1 epitope on CYP2D6. We tested the reactivity of sera from these patients to the homologous regions of the three autoantigens using an enzyme-linked immunosorbent assay (ELISA). The cut-off for positivity was established by testing sera from 22 healthy children. To determine the significance of reactivity to the peptide homologues of the three autoantigens, we investigated 16 additional patients with LKM1 AIH and 20 children with chronic hepatitis B virus infection as pathological controls. We found that reactivity to the second major epitope of CYP2D6 is significantly associated with reactivity to the homologous regions of carboxypeptidase H (CPH) and 21-hydroxylase (21-OHase) in patients with LKM1 AIH, and that this simultaneous recognition is cross-reactive. We suggest that a cross-reactive immune response between homologous autoantigens may contribute to the development of multiple endocrinopathies in LKM1 AIH.

Acetanilide 4-hydroxylase and acetanilide 2-hydroxylase activity in hepatic microsomes from induced mice.

Science.gov (United States)

Lewandowski, M; Chui, Y C; Levi, P; Hodgson, E

1991-02-01

A simple and sensitive method for the separation of 14C-labelled acetanilide, 4-hydroxyacetanilide, 3-hydroxyacetanilide and 2-hydroxyacetanilide was developed using thin-layer chromatography. This separation is the basis for the assay of acetanilide 4-hydroxylase and acetanilide 2-hydroxylase activity in liver microsomes from DBA2/N male mice that had been treated with phenobarbital, 3-methylcholanthrene, isosafrole or n-butylbenzodioxole. Microsomes were incubated with [14C]acetanilide and extracted with benzene and ethyl acetate. The extract was applied to silica gel plates and developed with a hexane/isopropanol/ammonium hydroxide/water solvent system. The radiolabelled phenolic metabolites and the parent compound were detected using a Berthold Automatic TLC Linear Analyzer. Although the 4-hydroxylated metabolite was the primary product detected, this method can be used to detect other phenolic metabolites.

Sera of children with hepatitis C infection and anti-liver-kidney microsome-1 antibodies recognize different CYP2D6 epitopes than adults with LKM+/HCV+ sera.

Science.gov (United States)

Herzog, D; Yamamoto, A M; Jara, P; Maggiore, G; Sarles, J; Alvarez, F

1999-11-01

Liver-kidney microsome type 1 (LKM1) antibodies are specific markers of autoimmune hepatitis (AIH) type 2. Antibodies to LKM1 have been found in 2% to 3% of adults infected with hepatitis C virus (HCV) without AIH. Thirty percent of these antibodies are directed against linear sequences of CYP2D6 protein. LKM1 antibodies in HCV+/LKM1+ sera and in sera of AIH patients do not recognize the same CYP2D6 epitopes. The current study was conducted to determine whether LKM1 antibodies in HCV+/LKM1+ children's sera are the result of the same immune response as the antibodies described in AIH type 2 and in HCV+/LKM1+ adult patients. Sera from 10 HCV+/LKM1+ children were tested against human liver microsomal and cytosolic proteins by Western blot analysis and against synthetic peptides of the CYP2D6 sequence between amino acids 200 and 429 by dot blot. The same sera were tested against radiolabeled CYP2D6 by immunoprecipitation. Four of 10 sera tested by Western blot analysis showed immunoglobulin (Ig) G-type antibodies against CYP2D6, and 2 had antibodies against proteins of 58, 66, and 84 kDa. One of the sera also contained IgM-type anti-66-kDa and 84-kDa proteins. The radioligand test detected anti-CYP2D6 antibodies in 9 of 10 patients. Five of the anti-CYP2D6-positive sera recognized a peptide between amino acids 200 and 429 including amino acids 254-271. Most HCV+/LKM1+ sera from children recognize conformational epitopes of the CYP2D6 antigen, and half recognize linear epitopes. Some HCV+/LKM1+ sera demonstrated antibodies against the AIH type 2 main antigenic site of the CYP2D6. Screening of HCV RNA should be performed before starting treatment of presumed autoimmune hepatitis associated with LKM1.

Exercise and Omega-3 Polyunsaturated Fatty Acid Supplementation for the Treatment of Hepatic Steatosis in Hyperphagic OLETF Rats

Directory of Open Access Journals (Sweden)

Sarah J. Borengasser

2012-01-01

Full Text Available Background and Aims. This study examined if exercise and omega-3 fatty acid (n3PUFA supplementation is an effective treatment for hepatic steatosis in obese, hyperphagic Otsuka Long-Evans Tokushima Fatty (OLETF rats. Methods. Male OLETF rats were divided into 4 groups (n=8/group: (1 remained sedentary (SED, (2 access to running wheels; (EX (3 a diet supplemented with 3% of energy from fish oil (n3PUFA-SED; and (4 n3PUFA supplementation plus EX (n3PUFA+EX. The 8 week treatments began at 13 weeks, when hepatic steatosis is present in OLETF-SED rats. Results. EX alone lowered hepatic triglyceride (TAG while, in contrast, n3PUFAs failed to lower hepatic TAG and blunted the ability of EX to decrease hepatic TAG levels in n3PUFAs+EX. Insulin sensitivity was improved in EX animals, to a lesser extent in n3PUFA+EX rats, and did not differ between n3PUFA-SED and SED rats. Only the EX group displayed higher complete hepatic fatty acid oxidation (FAO to CO2 and carnitine palmitoyl transferase-1 activity. EX also lowered hepatic fatty acid synthase protein while both EX and n3PUFA+EX decreased stearoyl CoA desaturase-1 protein. Conclusions. Exercise lowers hepatic steatosis through increased complete hepatic FAO, insulin sensitivity, and reduced expression of de novo fatty acid synthesis proteins while n3PUFAs had no effect.

Effect of Octreotide on Hepatic Steatosis in Diet-Induced Obesity in Rats.

Directory of Open Access Journals (Sweden)

Mao Li

Full Text Available Non-alcoholic fatty liver disease (NAFLD caused by liver lipid dysregulation is linked to obesity. Somatostatin (SST and its analogs have been used to treat pediatric hypothalamic obesity. However, the application of such drugs for the treatment of NAFLD has not been evaluated.This study aimed to investigate the expression levels of important regulators of hepatic lipid metabolism and the possible effect of the SST analog octreotide on these regulators.SD rats were assigned to a control group and a high-fat diet group. Obese rats from the high-fat diet group were further divided into the obese and octreotide-treated groups. The body weight, plasma SST, fasting plasma glucose (FPG, insulin, triglyceride (TG, total cholesterol (TC, low-density lipoprotein cholesterol (LDL-C, high-density lipoprotein cholesterol (HDL-C and free fatty acid (FFA levels were measured. Hepatic steatosis was evaluated based on the liver TG content, HE staining and oil red O staining. The SREBP-1c, ACC1, FAS, MTP, apoB and ADRP expression levels in the liver were also determined by RT-PCR, qRT-PCR, western blot or ELISA.The obese rats induced by high-fat diet expressed more SREBP-1c, FAS and ADRP but less MTP protein in the liver than those of control rats, whereas octreotide intervention reversed these changes and increased the level of apoB protein. Compared to the control group, obese rats showed increased liver ACC1, SREBP-1c and apoB mRNA levels, whereas octreotide-treated rats showed decreased mRNA levels of apoB and SREBP-1c. This was accompanied by increased body weight, liver TG contents, FPG, TG, TC, LDL-C, FFA, insulin and derived homeostatic model assessment (HOMA values. Octreotide intervention significantly decreased these parameters. Compared to the control group, the obese group showed a decreasing trend on plasma SST levels, which were significantly increased by the octreotide intervention.Octreotide can ameliorate hepatic steatosis in obese rats

Gastro Hepatic Protective Effects of Sildenafil in γ-Irradiated Rats

International Nuclear Information System (INIS)

Tawfik, S.S.; Salama, S.F.

2013-01-01

Sildenafil is a potent specific inhibitor of phosphodiesterase-5 (PDE-5), which ultimately increases intracellular cyclic guanosine monophosphate (cGMP) . Sildenafil commercially named Viagra; was studied for its gastro hepatic protective activity through acute exposure of rats to γ-rays. The experimental groups of rats were: Sildenafil [1 mg/ kg, intra venous (i.v.), in 0.2 ml saline] / day for 5 days and then exposed to 6 Gy γ-rays after 1 h of the last injection (sildenafil+ γ-rays group). Controls received saline as a vehicle/ for 5 day; sildenafil group received drug alone for 5 days, and γ-rays group received saline (without drug) for 5 days and exposed to 6 Gy γ-rays after 1 h of the last injection. All groups were decapitated on the 6th day. Gamma rays increased the level of malondialdehyde (MDA) and the activity of myeloperoxidase (MPO) but, lowered the levels of nitric oxide (NO) and reduced glutathione (GSH) as well as lowering the activities of superoxide dismutase (SOD) and catalase (CAT) in both stomach and hepatic tissues. Sildenafil administrated before γ-rays significantly reduced the level of MDA and the activity of MPO while elevating levels of NO and GSH plus activities of SOD and CAT in both stomach and hepatic tissues compared to control and sildenafil groups. Conclusion: The data reveals that sildenafil pre-treatment has a protective effect against γ-rays-induced gastro hepatic dysfunction and supports the possible use of sildenafil as a protective agent in γ-irradiated rats

Liver/kidney microsomal antibody type 1 targets CYP2D6 on hepatocyte plasma membrane

OpenAIRE

Muratori, L; Parola, M; Ripalti, A; Robino, G; Muratori, P; Bellomo, G; Carini, R; Lenzi, M; Landini, M; Albano, E; Bianchi, F

2000-01-01

BACKGROUND—Liver/kidney microsomal antibody type 1 (LKM1) is the marker of type 2 autoimmune hepatitis (AIH) and is detected in up to 6% of patients with hepatitis C virus (HCV) infection. It recognises linear and conformational epitopes of cytochrome P450IID6 (CYP2D6) and may have liver damaging activity, provided that CYP2D6 is accessible to effector mechanisms of autoimmune attack.
METHODS—The presence of LKM1 in the plasma membrane was investigated by indirect immunofluorescence and confo...

Metabolism, oral bioavailability and pharmacokinetics of chemopreventive kaempferol in rats

Science.gov (United States)

Barve, Avantika; Chen, Chi; Hebbar, Vidya; Desiderio, Joseph; Saw, Constance Lay-Lay; Kong, Ah-Ng

2012-01-01

The purpose of this study was to compare the hepatic and small intestinal metabolism, and examine bioavailability and gastro-intestinal first-pass effects of Kaempferol in the rats. Liver and small intestinal microsomes fortified with either NADPH or UDPGA were incubated with varying concentrations of Kaempferol for upto 120 minutes. Based on the values of the kinetic constants (Km and Vmax), the propensity for UDPGA-dependent conjugation as compared to NADPH-dependent oxidative metabolism was higher for both hepatic and small intestinal microsomes. Male Sprague-Dawley rats were administered Kaempferol intravenously (IV) (10, 25 mg/kg) or orally (100, 250 mg/kg). Gastro-intestinal first pass effects were observed by collecting portal blood after oral administration of 100 mg/kg Kaempferol. Pharmacokinetic parameters were obtained by Noncompartmental analysis using WinNonlin. After IV administration, the plasma concentration-time profiles for 10 and 25 mg/kg were consistent with high clearance (~ 3 L/hr/kg) and large volumes of distribution (8-12 L/kg). The disposition was characterized by a terminal half-life value of 3-4 hours. After oral administration the plasma concentration-time profiles demonstrated fairly rapid absorption (tmax ~ 1-2 hours). The area under the curve (AUC) values after IV and oral doses increased proportional to the dose. The bioavailability (F) was poor at ~ 2%. Analysis of portal plasma after oral administration revealed low to moderate absorption. Taken together, the low F of Kaempferol is attributed in part to extensive first-pass metabolism by glucuronidation and other metabolic pathways in the gut and in the liver. PMID:19722166

Accretion of visceral fat and hepatic insulin resistance in pregnant rats.

Science.gov (United States)

Einstein, Francine H; Fishman, Sigal; Muzumdar, Radhika H; Yang, Xiao Man; Atzmon, Gil; Barzilai, Nir

2008-02-01

Insulin resistance (IR) is a hallmark of pregnancy. Because increased visceral fat (VF) is associated with IR in nonpregnant states, we reasoned that fat accretion might be important in the development of IR during pregnancy. To determine whether VF depots increase in pregnancy and whether VF contributes to IR, we studied three groups of 6-mo-old female Sprague-Dawley rats: 1) nonpregnant sham-operated rats (Nonpreg; n = 6), 2) pregnant sham-operated rats (Preg; n = 6), and 3) pregnant rats in which VF was surgically removed 1 mo before mating (PVF-; n = 6). VF doubled by day 19 of pregnancy (Nonpreg 5.1 +/- 0.3, Preg 10.0 +/- 1.0 g, P Insulin sensitivity was measured by hyperinsulinemic-euglycemic clamp in late gestation in chronically catheterized unstressed rats. Glucose IR (mg.kg(-1).min(-1)) was highest in Nonpreg (19.4 +/- 2.0), lowest in Preg (11.1 +/- 1.4), and intermediate in PVF- (14.7 +/- 0.6; P insulin sensitivity than Preg [hepatic glucose production (HGP): Nonpreg 4.5 +/- 1.3, Preg 9.3 +/- 0.5 mg.kg(-1).min(-1); P insulin sensitivity was similar to nonpregnant levels in PVF- (HGP 4.9 +/- 0.8 mg.kg(-1).min(-1)). Both pregnant groups had lower peripheral glucose uptake compared with Nonpreg. In parallel with hepatic insulin sensitivity, hepatic triglyceride content was increased in pregnancy (Nonpreg 1.9 +/- 0.4 vs. Preg 3.2 +/- 0.3 mg/g) and decreased with removal of VF (PVF- 1.3 +/- 0.4 mg/g; P insulin action in pregnancy.

Partial Portal Vein Arterialization Attenuates Acute Bile Duct Injury Induced by Hepatic Dearterialization in a Rat Model.

Science.gov (United States)

Jiang, Jun; Wei, Jishu; Wu, Junli; Gao, Wentao; Li, Qiang; Jiang, Kuirong; Miao, Yi

2016-01-01

Hepatic infarcts or abscesses occur after hepatic artery interruption. We explored the mechanisms of hepatic deprivation-induced acute liver injury and determine whether partial portal vein arterialization attenuated this injury in rats. Male Sprague-Dawley rats underwent either complete hepatic arterial deprivation or partial portal vein arterialization, or both. Hepatic ischemia was evaluated using biochemical analysis, light microscopy, and transmission electron microscopy. Hepatic ATP levels, the expression of hypoxia- and inflammation-associated genes and proteins, and the expression of bile transporter genes were assessed. Complete dearterialization of the liver induced acute liver injury, as evidenced by the histological changes, significantly increased serum biochemical markers, decreased ATP content, increased expression of hypoxia- and inflammation-associated genes and proteins, and decreased expression of bile transporter genes. These detrimental changes were extenuated but not fully reversed by partial portal vein arterialization, which also attenuated ductular reaction and fibrosis in completely dearterialized rat livers. Collectively, complete hepatic deprivation causes severe liver injury, including bile infarcts and biloma formation. Partial portal vein arterialization seems to protect against acute ischemia-hypoxia-induced liver injury.

Partial Portal Vein Arterialization Attenuates Acute Bile Duct Injury Induced by Hepatic Dearterialization in a Rat Model

Directory of Open Access Journals (Sweden)

Jun Jiang

2016-01-01

Full Text Available Hepatic infarcts or abscesses occur after hepatic artery interruption. We explored the mechanisms of hepatic deprivation-induced acute liver injury and determine whether partial portal vein arterialization attenuated this injury in rats. Male Sprague-Dawley rats underwent either complete hepatic arterial deprivation or partial portal vein arterialization, or both. Hepatic ischemia was evaluated using biochemical analysis, light microscopy, and transmission electron microscopy. Hepatic ATP levels, the expression of hypoxia- and inflammation-associated genes and proteins, and the expression of bile transporter genes were assessed. Complete dearterialization of the liver induced acute liver injury, as evidenced by the histological changes, significantly increased serum biochemical markers, decreased ATP content, increased expression of hypoxia- and inflammation-associated genes and proteins, and decreased expression of bile transporter genes. These detrimental changes were extenuated but not fully reversed by partial portal vein arterialization, which also attenuated ductular reaction and fibrosis in completely dearterialized rat livers. Collectively, complete hepatic deprivation causes severe liver injury, including bile infarcts and biloma formation. Partial portal vein arterialization seems to protect against acute ischemia-hypoxia-induced liver injury.

EFFECTS OF THIOL ANTIOXIDANTS ON THE ATROPSELECTIVE OXIDATION OF 2,2′,3,3′,6,6′-HEXACHLOROBIPHENYL (PCB 136) BY RAT LIVER MICROSOMES

Science.gov (United States)

Wu, Xianai; Lehmler, Hans-Joachim

2015-01-01

Chiral polychlorinated biphenyl (PCB) congeners, such as PCB 136, are atropselectively metabolized to various hydroxylated PCB metabolites (HO-PCBs). The present study investigates the effect of two thiol antioxidants, glutathione and N-acetyl-cysteine (NAC), on profiles and chiral signatures of PCB 136 and its HO-PCB metabolites in rat liver microsomal incubations. Liver microsomes prepared from rats pretreated with phenobarbital were incubated with PCB 136 (5 μM) in the presence of the respective antioxidant (0–10 mM), and levels and chiral signatures of PCB 136 and its HO-PCB metabolites were determined. Three metabolites, 5-136 (2,2′,3,3′,6,6′-hexachlorobiphenyl-5-ol), 4-136 (2,2′,3,3′,6,6′-hexachlorobiphenyl-4-ol) and 4,5-136 (2,2′,3,3′,6,6′-hexachlorobiphenyl-4,5-diol), were detected in all incubations, with 5-136 being the major metabolite. Compared to microsomal incubations without antioxidant, levels of 4,5-136 increased with increasing antioxidant concentration, whereas levels of PCB 136 and both mono-HO-PCBs were not affected by the presence of either antioxidant. PCB 136, 4-136 and 5-136 displayed significant atropisomeric enrichment; however, the direction and extent of the atropisomeric enrichment was not altered in the presence of an antioxidant. Because 4,5-136 can either be conjugated to a sulfate or glucuronide metabolite that is readily excreted or further oxidized a potentially toxic PCB 136 quinone, the effect of both thiol antioxidants on 4,5-136 formation suggests that disruptions of glutathione homeostasis may alter the balance between both metabolic pathways and, thus, PCB 136 toxicity in vivo. PMID:26155892

Metabolism of ethylbenzene by human liver microsomes and recombinant human cytochrome P450s (CYP).

Science.gov (United States)

Sams, Craig; Loizou, George D; Cocker, John; Lennard, Martin S

2004-03-07

The enzyme kinetics of the initial hydroxylation of ethylbenzene to form 1-phenylethanol were determined in human liver microsomes. The individual cytochrome P450 (CYP) forms catalysing this reaction were identified using selective inhibitors and recombinant preparations of hepatic CYPs. Production of 1-phenylethanol in hepatic microsomes exhibited biphasic kinetics with a high affinity, low Km, component (mean Km = 8 microM; V(max) = 689 pmol/min/mg protein; n = 6 livers) and a low affinity, high Km, component (Km = 391 microM; V(max) = 3039 pmol/min/mg protein; n = 6). The high-affinity component was inhibited 79%-95% (mean 86%) by diethyldithiocarbamate, and recombinant CYP2E1 was shown to metabolise ethylbenzene with low Km (35 microM), but also low (max) (7 pmol/min/pmol P450), indicating that this isoform catalysed the high-affinity component. Recombinant CYP1A2 and CYP2B6 exhibited high V(max) (88 and 71 pmol/min/pmol P450, respectively) and high Km (502 and 219 microM, respectively), suggesting their involvement in catalysing the low-affinity component. This study has demonstrated that CYP2E1 is the major enzyme responsible for high-affinity side chain hydroxylation of ethylbenzene in human liver microsomes. Activity of this enzyme in the population is highly variable due to induction or inhibition by physiological factors, chemicals in the diet or some pharmaceuticals. This variability can be incorporated into the risk assessment process to improve the setting of occupational exposure limits and guidance values for biological monitoring.

Comparison of hepatic fibrosis models and associated hepatic fibronectin expression in Wistar rats treated by bile duct ligation and CCl4

Directory of Open Access Journals (Sweden)

LIU Xiaoya

2015-02-01

Full Text Available ObjectiveTo compare serum biochemical parameters, liver pathology, and fibronectin (FN expression in Wister rats with hepatic fibrosis induced by bile duct ligation (BDL and carbon tetrachloride (CCl4. MethodsNinety healthy male Wister rats were assigned to CCl4 model (n=44, CCl4 control (n=6, BDL model (n=30, and BDL control groups (n=10. Animal models of hepatic fibrosis were established by intraperitoneal injection of olive oil solution containing 50% CCl4 in the CCl4 model group and by BDL in the BDL group. General conditions of rats were examined. Expression of serum alanine aminotransferase (ALT, serum aspartate aminotransferase (AST, total bilirubin (TBil, and direct bilirubin (DBil was measured by biochemical analysis. Expression of serum hyaluronic acid (HA and laminin (LN was measured by ELISA assay. Pathological changes in liver tissue were examined through hematoxylin-eosin and Masson staining. Expression of FN was assayed by immunohistochemistry. Comparison between groups was made by t test. ResultsSerum biochemical analysis showed that TBil and DBil levels in BDL model rats increased to and maintained at relatively high levels from day 7 after surgery (P<0.05; these two parameters in CCl4 model rats increased gradually from week 2 and peaked at week 8 after injection (P<0.05. The indicators of hepatic fibrosis, i.e., HA and LN levels, were significantly higher in the BDL model group than in the CCl4 model group. Pathologically, the CCl4 model group showed diffuse fatty degeneration of liver cells, with extremely significant fiber interval formation in the portal area - portal area or the portal area - central vein; the BDL model group showed coexistence of significant intrahepatic bile duct hyperplasia, inflammatory cell infiltration, and fiber interval formation. In the BDL model group, FN expression was dispersive and irregular with thin fibrous tissues; in the CCl4 model group, FN was mostly expressed in the interlobular septa

Modified sleeve anastomosis for reconstruction of the hepatic artery in rat liver transplantation.

Science.gov (United States)

Li, Jun; Dahmen, Uta; Dirsch, Olaf; Shen, Kai; Gu, Yanli; Broelsch, Christoph Erich

2002-01-01

End-to-end sleeve anastomosis between a donor common hepatic artery and a recipient proper hepatic artery was proven to be the most physiological and simple method for hepatic rearterialization in rat liver transplantation. Current technical variants of the sleeve technique, however, are hampered by the high rate of bleeding from the anastomotic site. This report deals with a technical modification which inhibits postoperative bleeding efficiently. The procedure consisted of a guiding suture, as previously described in other technical variants, and a modified fixing suture. Instead of using a single stitch to fix the feeding vessel with the receiving vessel, a running suture between the edge of the donor common hepatic artery and the adventitia of the recipient proper hepatic artery was performed to avoid a possible backflow. The patency rate of 91% was as high as reported by others using a sleeve technique, which was also reflected in the histomorphological picture, being indistinguishable from normal liver histology. This technical modification simplified the procedure of reconstructing the hepatic artery and could contribute to a wider use of the arterialized liver transplantation model in rats. Copyright 2002 Wiley-Liss, Inc.

Sex-related differences in NADPH-dependent lipid peroxidation induced by cadmium

Energy Technology Data Exchange (ETDEWEB)

Sato, Masao; Nagai, Yasushi

1986-10-01

Male and female rats were dosed once a day for 2 days with injections of 1.5 mg Cd/kg. Formation of thiobarbituric acid reactive substances (TBA-RS) was significantly increased in male rat liver but not in the females. NADPH-dependent lipid peroxidation in vitro in microsomes derived from untreated rat liver was greater in males than in females. Furthermore, addition of cadmium (Cd) to microsomes isolated from male rat liver produced a dose-dependent potentiation of NADPH-dependent lipid peroxidation from low concentrations of CD. In microsomes derived from females a significant increase in lipid peroxidation was observed only at high Cd concentrations. NADPH-dependent lipid peroxidation enhanced by Cd was greater in the males than in the females. These data suggest that a sex-related difference in the ability of Cd to induce lipid peroxidation in vivo in rat liver appears to be mediated partly through differences in hepatic microsomal NADPH-dependent lipid peroxidation.

Effects of Urtica dioica on hepatic ischemia‐reperfusion injury in rats

Science.gov (United States)

Kandis, Hayati; Karapolat, Sami; Yildirim, Umran; Saritas, Ayhan; Gezer, Suat; Memisogullari, Ramazan

2010-01-01

OBJECTIVES: To evaluate the effects of Urtica dioica on hepatic ischemia‐reperfusion injury. METHODS: Thirty adult male Wistar albino rats were divided into three groups: sham group (group 1), control group (group 2), and Urtica dioica group (group 3). All the rats were exposed to hepatic ischemia for 60 min, followed by 60 min of reperfusion. In group 2, a total of 2 ml/kg 0.9% saline solution was given intraperitoneally. In group 3, a total of 2 ml/kg Urtica dioica was given intraperitoneally. At the end of the procedure, liver tissue and blood samples were taken from all rats. Serum aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, ceruloplasmin, catalase, paraoxonase, arylesterase, and lipid hydroperoxide levels were measured. Liver tissue histopathologies were also evaluated by light microscopy. RESULTS: Serum aspartate aminotransferase, alanine aminotransferase and lactate dehydrogenase levels were significantly higher in group 2 than in group 1, and significantly lower in group 3 than in group 2. Also, group 2 had higher serum lipid hydroperoxides and ceruloplasmin levels but lower catalase, paraoxonase, and arylesterase levels than group 1. In group 3, serum lipid hydroperoxides and ceruloplasmin levels were significantly lower, and catalase, paraoxonase, and arylesterase levels were higher than those in group 2. Histopathological examination showed that liver tissue damage was significantly decreased in group 3 compared with group 2. CONCLUSIONS: Urtica dioica has a protective effect on the liver in hepatic ischemia‐reperfusion‐injured rats. PMID:21340227

Effects of Urtica dioica on hepatic ischemia-reperfusion injury in rats.

Science.gov (United States)

Kandis, Hayati; Karapolat, Sami; Yildirim, Umran; Saritas, Ayhan; Gezer, Suat; Memisogullari, Ramazan

2010-01-01

To evaluate the effects of Urtica dioica on hepatic ischemia-reperfusion injury. Thirty adult male Wistar albino rats were divided into three groups: sham group (group 1), control group (group 2), and Urtica dioica group (group 3). All the rats were exposed to hepatic ischemia for 60 min, followed by 60 min of reperfusion. In group 2, a total of 2 ml/kg 0.9% saline solution was given intraperitoneally. In group 3, a total of 2 ml/kg Urtica dioica was given intraperitoneally. At the end of the procedure, liver tissue and blood samples were taken from all rats. Serum aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, ceruloplasmin, catalase, paraoxonase, arylesterase, and lipid hydroperoxide levels were measured. Liver tissue histopathologies were also evaluated by light microscopy. Serum aspartate aminotransferase, alanine aminotransferase and lactate dehydrogenase levels were significantly higher in group 2 than in group 1, and significantly lower in group 3 than in group 2. Also, group 2 had higher serum lipid hydroperoxides and ceruloplasmin levels but lower catalase, paraoxonase, and arylesterase levels than group 1. In group 3, serum lipid hydroperoxides and ceruloplasmin levels were significantly lower, and catalase, paraoxonase, and arylesterase levels were higher than those in group 2. Histopathological examination showed that liver tissue damage was significantly decreased in group 3 compared with group 2. Urtica dioica has a protective effect on the liver in hepatic ischemia-reperfusion-injured rats.

Magnetic circular dichroism studies on microsomal aryl hydrocarbon hydroxylase: comparison with cytochrome b/sub 5/ and cytochrome P-450/sub cam/

Energy Technology Data Exchange (ETDEWEB)

Vickery, L; Salmon, A; Sauer, K

1975-01-01

Magnetic circular dichroism spectra are reported for the visible and near ultraviolet spectral regions of liver microsomes from dimethylbenzanthracene-treated rats. The sequential addition of NADH, dithionite, and carbon monoxide enables us to determine contributions to the magnetic circular dichroism by cytochromes b/sub 5/ and P-450, which dominate the spectra. The magnetic circular dichroism of the microsomal preparation is compared with that of purified oxidized and reduced cytochrome b/sub 5/ from pig liver and with the camphor-complexed and camphor-free oxidized, reduced, and reduced carbonmonoxy cytochrome P-450/sub cam/ from Pseudomonas putida. The magnetic circular dichroism spectra of the membrane bound cytochrome b/sub 5/ are similar to those of the purified protein, indicating that little or no alteration in the environment of the heme occurs during the isolation procedure. The soluble bacterial cytochrome P-450/sub cam/ also appears to be a suitable model for microsomal P-450, although differences in the magnetic circular dichroism intensity are observed for the two enzymes. No effect of dimethylbenzanthracene on the magnetic circular dichroism spectra of induced compared to control rat microsomes could be observed.

The determination of hepatic blood flow in the rat using Xenon-133

International Nuclear Information System (INIS)

Smith, A.; Clarke, M.B.

1976-01-01

The measurement of hepatic blood flow in rats undergoing surgical trauma using different anaesthetic techniques has been carried out using the 133 Xe clearance method. Injection into the hepatic artery is followed by monitoring of the liver radioactivity. The complex clearance curves have been analysed using a computer. Details of the surgical technique and the care of the animal while undergoing examination are given. The physiological basis for the clearance curves observed is analysed and a survey of the various parameters which may produce changes in clearance rates is made. Comparison with other investigations show that rat liver blood flows obtained using the 133 Xe clearance method are consistent with others using non-radioactive techniques; because of its simplicity and ease of repetition, the Xenon method is recommended as a way of evaluating drug effects on hepatic blood flow in experimental animals. (author)

[Autoimmune hepatitis in a girl with presence of anti-LKM1 antibodies].

Science.gov (United States)

Larraín, F; Miquel, J F; González, S

1997-06-01

Autoimmune hepatitis is an inflammatory liver disease characterized by dense mononuclear cell infiltrate in the portal tract, and serologically by the presence of non-organ and liver-specific autoantibodies and increased levels of gammaglobulins in the absence of a known etiology. Three subgroups of autoimmune hepatitis have been recognized, depending on the nature of the autoantibody present in the serum: Type 1 autoimmune hepatitis, associated with smooth-muscle (SMA) or antinuclear antibody (ANA) seropositivity; type 2, with anti-liver/kidney microsome antibody (anti-LKM1), and type 3, with the absence of ANA, SMA and anti-LKM1 and presence of other autoantibodies such as anti-soluble liver antigen (SLA). Subtypes of chronic autoimmune hepatitis have clinically different features and prognoses. An 8 year old female patient presented mild jaundice of insidious onset. The liver was tender and enlarged. Serologic markers for A, B, C, E, Epstein Barr and cytomegalovirus were negative. The liver biopsy showed a histological picture consistent with chronic active hepatitis. High titers of anti-liver/kidney-microsome antibody were found by indirect immunofluorescence test, and this finding was confirmed by Western blot against specific liver microsome antigens. Therapy with prednisolone induced a clinical and biochemical remission after four weeks. The suspension of therapy under strict medical control produced a rapid relapse of clinical and biochemical features. The reinitiation of prednisolone was successful, and an alternate-day program was started and maintained until 8 months follow-up.

Sex-related difference in the inductions by perfluoro-octanoic acid of peroxisomal beta-oxidation, microsomal 1-acylglycerophosphocholine acyltransferase and cytosolic long-chain acyl-CoA hydrolase in rat liver.

Science.gov (United States)

Kawashima, Y; Uy-Yu, N; Kozuka, H

1989-01-01

Inductions by perfluoro-octanoic acid (PFOA) of hepatomegaly, peroxisomal beta-oxidation, microsomal 1-acylglycerophosphocholine acyltransferase and cytosolic long-chain acyl-CoA hydrolase were compared in liver between male and female rats. Marked inductions of these four parameters were seen concurrently in liver of male rats, whereas the inductions in liver of female rats were far less pronounced. The sex-related difference in the response of rat liver to PFOA was much more marked than that seen with p-chlorophenoxyisobutyric acid (clofibric acid) or 2,2'-(decamethylenedithio)diethanol (tiadenol). Hormonal manipulations revealed that this sex-related difference in the inductions is strongly dependent on sex hormones, namely that testosterone is necessary for the inductions, whereas oestradiol prevented the inductions by PFOA. PMID:2570571

Pyrethroid insecticide lambda-cyhalothrin induces hepatic cytochrome P450 enzymes, oxidative stress and apoptosis in rats.

Science.gov (United States)

Martínez, María-Aránzazu; Ares, Irma; Rodríguez, José-Luis; Martínez, Marta; Roura-Martínez, David; Castellano, Victor; Lopez-Torres, Bernardo; Martínez-Larrañaga, María-Rosa; Anadón, Arturo

2018-08-01

This study aimed to examine in rats the effects of the Type II pyrethroid lambda-cyhalothrin on hepatic microsomal cytochrome P450 (CYP) isoform activities, oxidative stress markers, gene expression of proinflammatory, oxidative stress and apoptosis mediators, and CYP isoform gene expression and metabolism phase I enzyme PCR array analysis. Lambda-cyhalothrin, at oral doses of 1, 2, 4 and 8mg/kg bw for 6days, increased, in a dose-dependent manner, hepatic activities of ethoxyresorufin O-deethylase (CYP1A1), methoxyresorufin O-demethylase (CYP1A2), pentoxyresorufin O-depentylase (CYP2B1/2), testosterone 7α- (CYP2A1), 16β- (CYP2B1), and 6β-hydroxylase (CYP3A1/2), and lauric acid 11- and 12-hydroxylase (CYP4A1/2). Similarly, lambda-cyhalothrin (4 and 8mg/kg bw, for 6days), in a dose-dependent manner, increased significantly hepatic CYP1A1, 1A2, 2A1, 2B1, 2B2, 2E1, 3A1, 3A2 and 4A1 mRNA levels and IL-1β, NFκB, Nrf2, p53, caspase-3 and Bax gene expressions. PCR array analysis showed from 84 genes examined (P1.5), changes in mRNA levels in 18 genes: 13 up-regulated and 5 down-regulated. A greater fold change reversion than 3-fold was observed on the up-regulated ALDH1A1, CYP2B2, CYP2C80 and CYP2D4 genes. Ingenuity Pathway Analysis (IPA) groups the expressed genes into biological mechanisms that are mainly related to drug metabolism. In the top canonical pathways, Oxidative ethanol degradation III together with Fatty Acid α-oxidation may be significant pathways for lambda-cyhalothrin. Our results may provide further understanding of molecular aspects involved in lambda-cyhalothrin-induced liver injury. Copyright © 2018. Published by Elsevier B.V.

Impact of high altitude on the hepatic fatty acid oxidation and synthesis in rats

Energy Technology Data Exchange (ETDEWEB)

Ni, Qian [Department of General Surgery, Hepatic-biliary-pancreatic Institute, Lanzhou University Second Hospital, Lanzhou (China); Department of Pediatrics, Lanzhou University Second Hospital, Lanzhou (China); Shao, Yuan; Wang, Ying Zhen [Department of General Surgery, Hepatic-biliary-pancreatic Institute, Lanzhou University Second Hospital, Lanzhou (China); Jing, Yu Hong [Institute of Anatomy, School of Basic Medicine, Lanzhou University, Lanzhou (China); Zhang, You Cheng, E-mail: zhangychmd@126.com [Department of General Surgery, Hepatic-biliary-pancreatic Institute, Lanzhou University Second Hospital, Lanzhou (China)

2014-04-04

Highlights: • Acute exposure to high altitude (HA) increased hepatic fatty acid (FA) β-oxidation. • Acute exposure of rats to HA increased hepatic FA synthesis. • PPARα and AMPK can regulate the FA metabolism. • FA may be a key energy fuel and a compensation for CHO during acute exposure to HA. • The acute changes of FA metabolism may be a mechanism of acclimatization. - Abstract: High altitude (HA) affects energy metabolism. The impact of acute and chronic HA acclimatization on the major metabolic pathways is still controversial. In this study, we aimed to unveil the impact of HA on the key enzymes involved in the fatty acid (FA) metabolism in liver. Rats were exposed to an altitude of 4300 m for 30 days and the expressions of two key proteins involved in FA β-oxidation (carnitine palmitoyl transferase I, CPT-I; and peroxisome proliferator-activated receptor alpha, PPARα), two proteins involved in FA synthesis (acetyl CoA carboxylase-1, ACC-1; and AMP-activated protein kinase, AMPK), as well as the total ketone body in the liver and the plasma FFAs were examined. Rats without HA exposure were used as controls. We observed that the acute exposure of rats to HA (3 days) led to a significant increase in the expressions of CPT-I and PPARα and in the total hepatic ketone body. Longer exposure (15 days) caused a marked decrease in the expression of CPT-I and PPARα. By 30 days after HA exposure, the expression levels of CPT-I and PPARα returned to the control level. The hepatic ACC-1 level showed a significant increase in rats exposed to HA for 1 and 3 days. In contrast, the hepatic level of AMPK showed a significant reduction throughout the experimental period. Plasma FFA concentrations did not show any significant changes following HA exposure. Thus, increased hepatic FA oxidation and synthesis in the early phase of HA exposure may be among the important mechanisms for the rats to respond to the hypoxic stress in order to acclimatize themselves to the

Impact of high altitude on the hepatic fatty acid oxidation and synthesis in rats

International Nuclear Information System (INIS)

Ni, Qian; Shao, Yuan; Wang, Ying Zhen; Jing, Yu Hong; Zhang, You Cheng

2014-01-01

Highlights: • Acute exposure to high altitude (HA) increased hepatic fatty acid (FA) β-oxidation. • Acute exposure of rats to HA increased hepatic FA synthesis. • PPARα and AMPK can regulate the FA metabolism. • FA may be a key energy fuel and a compensation for CHO during acute exposure to HA. • The acute changes of FA metabolism may be a mechanism of acclimatization. - Abstract: High altitude (HA) affects energy metabolism. The impact of acute and chronic HA acclimatization on the major metabolic pathways is still controversial. In this study, we aimed to unveil the impact of HA on the key enzymes involved in the fatty acid (FA) metabolism in liver. Rats were exposed to an altitude of 4300 m for 30 days and the expressions of two key proteins involved in FA β-oxidation (carnitine palmitoyl transferase I, CPT-I; and peroxisome proliferator-activated receptor alpha, PPARα), two proteins involved in FA synthesis (acetyl CoA carboxylase-1, ACC-1; and AMP-activated protein kinase, AMPK), as well as the total ketone body in the liver and the plasma FFAs were examined. Rats without HA exposure were used as controls. We observed that the acute exposure of rats to HA (3 days) led to a significant increase in the expressions of CPT-I and PPARα and in the total hepatic ketone body. Longer exposure (15 days) caused a marked decrease in the expression of CPT-I and PPARα. By 30 days after HA exposure, the expression levels of CPT-I and PPARα returned to the control level. The hepatic ACC-1 level showed a significant increase in rats exposed to HA for 1 and 3 days. In contrast, the hepatic level of AMPK showed a significant reduction throughout the experimental period. Plasma FFA concentrations did not show any significant changes following HA exposure. Thus, increased hepatic FA oxidation and synthesis in the early phase of HA exposure may be among the important mechanisms for the rats to respond to the hypoxic stress in order to acclimatize themselves to the

Irreversible binding of 14C-labelled trichloroethylene to mice liver constituents in vivo and in vitro

International Nuclear Information System (INIS)

Uehleke, H.; Poplawski-Tabarelli, S.

1977-01-01

1) 14 C-labelled trichloroethylene was injected i.p. into male mice (10 μmole/g of b.w.). The radioactivity irreversibly bound to hepatic protein reached highest levels after 6 h : 2 nmole/mg in cytosol protein, 4.4 nmole/mg in mitochondrial protein, and 7.6 nmole/mg in microsomal protein. 2) The commercial trichloroethylene contained radioactive impurities binding to proteins without metabolic activation. Purification by various extraction removed 60-70% of those materials. In aerobic incubates of mice hepatic microsomes and NADPH the covalent binding rate of the purified trichloroethylene was 1.4 nmole/mg protein in 60 min. The activity of rat liver microsomes was approximately 40% less. Covalent binding increased 2-fold with microsomes of mice pretreated with phenobarbital. (orig.) [de

Investigation of pharmacological responses to anti-diabetic drugs in female Spontaneously Diabetic Torii (SDT) fatty rats, a new nonalcoholic steatohepatitis (NASH) model.

Science.gov (United States)

Toriniwa, Yasufumi; Saito, Tomoyuki; Miyajima, Katsuhiro; Ishii, Yukihito; Uno, Kinuko; Maekawa, Tatsuya; Matsui, Tohru; Kume, Shinichi; Yamada, Takahisa; Ohta, Takeshi

2018-04-10

Nonalcoholic steatohepatitis (NASH) is a progressive liver disease, and some patients develop hepatic cirrhosis/carcinoma. Animal models play key roles in the development of new therapies for NASH. In this study, the pharmacological effects of metformin and pioglitazone were investigated in female Spontaneously Diabetic Torii (SDT) fatty rats to verify the utility of this model. The anti-diabetic drugs were administered to SDT fatty rats fed a cholesterol-enriched diet from 4 to 25 weeks, and changes in food intake, body weight, and blood chemistry parameters were evaluated every 4 weeks. The hepatic lipid content, mRNA expression in relation to lipid synthesis, inflammation, and fibrosis, and histopathological analyses were performed at 25 weeks. Pioglitazone improved hyperglycemia, hyperlipidemia, and abnormalities in hepatic parameters. The insulin levels were lower than those in the control rats before 16 weeks. Plasma glucose levels in the metformin-treated rats were lower than those in the control rats, and plasma triglyceride and alanine aminotransferase levels temporarily decreased. The lipid content and some mRNA expression in relation to fibrosis in the liver decreased with pioglitazone treatment, and the mRNA expression of microsomal triglyceride transfer protein increased. Hepatic fibrosis observed in the SDT fatty rats improved with pioglitazone treatment; however, the effect with metformin treatment was partial. These results in both drugs are in line with results in the human study, suggesting that the SDT fatty rat is useful for developing new anti-NASH drugs that show potential to regulate glucose/lipid metabolism.

Effect of pyridoxine deficiency on cholesterogenesis in rats fed different levels of protein

International Nuclear Information System (INIS)

Okada, Mitsuko; Iwami, Tamako

1977-01-01

Hepatic cholesterol contents in rats fed a 70% or 20% casein diet with or without pyridoxine was determined. In the case of the 70% casein group, pyridoxine-deficient rats showed a higher content than the control. The increment was mainly due to the accumulation of an ester form of the cholesterol. On the other hand, pyridoxine-deficient rats in the 20% casein group showed a slightly lower content. The cholesterol content in liver microsomal fractions was lower in the 20%-casein pyridoxine-deficient group and serum cholesterol level was lower in the 70%-casein pyridoxine-deficient group than those in respective control groups. Incorporation of [ 14 C] acetate into cholesterol was studied using liver slices, and significant stimulation was observed in pyridoxine-deficient rat fed a 20% or 70% casein diet. There was no difference in intestinal cholesterogenesis between the control and the deficient groups. (auth.)

The relationship between plasma free fatty acids and experimentally induced hepatic encephalopathy in the rat

NARCIS (Netherlands)

Smit, J. J.; Bosman, D. K.; Jörning, G. G.; de Haan, J. G.; Maas, M. A.; Chamuleau, R. A.

1991-01-01

Two experimental models of hepatic encephalopathy in the rat have been investigated in order to study the postulated relationship between plasma free fatty acids concentration (C6 - C22:0) and the degree of hepatic encephalopathy. As a model of chronic hepatic encephalopathy, porta caval shunted

Roles of different forms of cytochrome P450 in the activation of the promutagen 6-aminochrysene to genotoxic metabolites in human liver microsomes.

Science.gov (United States)

Yamazaki, H; Mimura, M; Oda, Y; Inui, Y; Shiraga, T; Iwasaki, K; Guengerich, F P; Shimada, T

1993-07-01

We reported previously that the potent mutagen 6-aminochrysene is catalyzed principally by rat liver microsomal P4501A and P4502B enzymes to reactive metabolites that induce umu gene expression in O-acetyltransferase-over-expressing strain Salmonella typhimurium NM2009; the proposal was made that there are different mechanisms in the formation of reactive N-hydroxylated and diolepoxide metabolites by P450 enzymes (Yamazaki, H. and Shimada, T., Biochem. Pharmacol., 44, 913-920, 1992). Here we further examined the roles of human liver P450 enzymes and the mechanism of activation of 6-aminochrysene by rat and human P450 enzymes in the Salmonella tester strains. Liver microsomes from 18 different human samples catalyzed activation of 6-aminochrysene more efficiently in S. typhimurium NM2009 than in the original strain of S. typhimurium TA1535/pSK1002. The rates of 6-aminochrysene activation in 18 human liver samples showed good correlation to the contents of P4502B6 as well as contents of P4503A4 and the respective mono-oxygenase activities catalyzed by P4503A4. Among purified P450 enzymes examined, P4501A2 as well as P4503A4 were highly active in transforming 6-amino-chrysene to reactive metabolites, suggesting the involvement of different human P450 enzymes in the reaction. Four human samples that contained relatively high levels of particular P450 enzymes in their microsomes were selected and used for further characterization. Liver microsomes from human samples HL-13 and HL-4 that contained the highest levels of P4502B6 and P4503A4 respectively, were sensitive to the respective antibodies raised against monkey P4502B and human P4503A4; the activity in sample HL-16 having the highest level of P4501A2 was inhibited by anti-P4501A2 IgG. alpha-Naphthoflavone enhanced the activation of 6-aminochrysene very significantly in human liver microsomes enriched in P4503A4 and P4502B6 enzymes. Pentachlorophenol, an inhibitor of acetyltransferase activity, suppressed the

Zinc-induced protection against cadmium

Energy Technology Data Exchange (ETDEWEB)

Early, J.L.; Schnell, R.C.

1978-02-01

Pretreatment of male rats with cadmium acetate potentiates the duration of hexobarbital hypnosis and inhibits the rate of hepatic microsomal drug metabolism. Pretreatment of rats with zinc acetate protects against these alterations in drug action elicited by cadmium.

Dietary intake of ain-93 standard diet induces Fatty liver with altered hepatic fatty acid profile in Wistar rats.

Science.gov (United States)

Farias Santos, Juliana; Suruagy Amaral, Monique; Lima Oliveira, Suzana; Porto Barbosa, Júnia; Rego Cabral, Cyro; Sofia Melo, Ingrid; Bezerra Bueno, Nassib; Duarte Freitas, Johnatan; Goulart Sant'ana, Antônio; Rocha Ataíde, Terezinha

2015-05-01

There are several standard diets for animals used in scientific research, usually conceived by scientific institutions. The AIN-93 diet is widely used, but there are some reports of fatty liver in Wistar rats fed this diet. We aimed to evaluate the hepatic repercussions of the AIN-93 diet intake in Wistar rats. Forty newly-weaned 21-day-old male Wistar rats were fed either the AIN-93 diet or a commercial diet for either 1 month or 4 months. Weight gain, serum biochemistry, hepatic histology, and hepatic fatty acid profile were analyzed. Hepatic steatosis was observed, especially in the group fed the AIN-93 diet. Serum blood glucose, absolute and relative liver weight and hepatic levels of oleic, palmitoleic, stearic, and palmitic fatty acids were related to the observed steatosis, while lipidogram and serum markers of liver function and injury were not. AIN-93 diet induced acute hepatic steatosis in Wistar rats, which may compromise its use as a standard diet for experimental studies with rodents. The hepatic fatty acid profile was associated with steatosis, with possible implications for disease prognosis. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

In vitro screening of reversible and time-dependent inhibition on CYP3A by TM208 and TM209 in rat liver microsomes

Directory of Open Access Journals (Sweden)

Miaoran Ning

2012-04-01

Full Text Available TM208 and TM209, dithiocarbamate derivatives with potential anti-cancer effects, were evaluated in reversible and time-dependent cytochrome P450 (CYP 3A inhibition assays in rat liver microsomes using testosterone as probe substrate. Both compounds were found to be weak reversible inhibitors and moderate mechanism-based inhibitors of rat CYP3A. For reversible inhibition on rat CYP3A, the Ki values of competitive inhibition model were 12.10±1.75 and 13.94±1.31 μM, respectively. For time-dependent inhibition, the inactivation constants (Kl were 31.93±12.64 and 32.91±15.58 μM, respectively, and the maximum inactivation rates (kinact were 0.03497±0.0069 and 0.07259±0.0172 min−1 respectively. These findings would provide useful in vitro information for future in vivo DDI studies on TM208 or TM209.

Microsomal protein synthesis inhibition: an early manifestation of gentamicin nephrotoxicity

International Nuclear Information System (INIS)

Bennett, W.M.; Mela-Riker, L.M.; Houghton, D.C.; Gilbert, D.N.; Buss, W.C.

1988-01-01

Aminoglycoside antibiotics achieve bacterial killing by binding to bacterial ribosomes and inhibiting protein synthesis. To examine whether similar mechanisms could be present in renal tubular cells prior to the onset of overt proximal tubular necrosis due to these drugs, we isolated microsomes from Fischer rats given 20 mg/kg gentamicin every 12 h subcutaneously for 2 days and from vehicle-injected controls. Concomitant studies of renal structure, function, and mitochondrial respiration were carried out. [3H]leucine incorporation into renal microsomes of treated animals was reduced by 21.9% (P less than 0.01), whereas brain and liver microsomes from the same animals were unaffected. Gentamicin concentration in the renal microsomal preparation was 56 micrograms/ml, a value 7- to 10-fold above concentrations necessary to inhibit bacterial growth. Conventional renal function studies were normal (blood urea, serum creatinine, creatinine clearance). Treated animals showed only a mild reduction of inulin clearance, 0.71 compared with 0.93 ml.min-1.100 g-1 in controls (P less than 0.05), and an increase in urinary excretion of N-acetylglucosaminidase of 20 compared with 14.8 units/l (P less than 0.05). Renal slice transport of p-aminohippuric acid, tetraethylammonium, and the fractional excretion of sodium were well preserved. There was no evidence, as seen by light microscopy, of proximal tubular necrosis. Mitochondrial cytochrome concentrations were normal and respiratory activities only slightly reduced. Processes similar to those responsible for bacterial killing could be involved in experimental gentamicin nephrotoxicity before overt cellular necrosis

The regulatory effects of fish oil and chitosan on hepatic lipogenic signals in high-fat diet-induced obese rats.

Science.gov (United States)

Chiu, Chen-Yuan; Chang, Tien-Chia; Liu, Shing-Hwa; Chiang, Meng-Tsan

2017-10-01

The present study investigated the regulatory effects of fish oil and chitosan on the signals of hepatic lipid metabolism and the postulated mechanism in high-fat diet-induced obese rats. Diet supplementation of chitosan and fish oil efficiently suppressed the increased weights in body and livers of high-fat diet-fed rats. Supplementation of chitosan and fish oil significantly decreased the activities of hepatic lipid biosynthesis-related enzymes and efficiently regulated plasma lipoprotein homeostasis. Both chitosan and fish oil significantly ameliorated the alterations in the protein expressions of hepatic lipogenic transcription factors (LXRα and PPARα), and could also significantly regulate the downstream hepatic lipogenic genes (FAS, HMGCR, CYP7A1, FATP, FABP, AOX, and ABCA) expressions in high-fat diet-fed rats. These results suggest that both fish oil and chitosan exerts downregulative effects on hepatic lipid metabolism in high-fat diet-induced obese rats via the LXRα inhibition and PPARα activation, which further affect the expressions of hepatic lipogenesis-associated genes. Copyright © 2017. Published by Elsevier B.V.

Auto-immune hepatitis following delivery.

Science.gov (United States)

Saini, Vandana; Gupta, Mamta; Mishra, S K

2013-05-01

Auto-immune hepatitis first presenting in the early postpartum period is rare. Immunosuppressive effects of pregnancy result in delayed manifestation of auto-immune hepatitis, and in established cases, the spontaneous improvements are there. Auto-immune hepatitis should be considered in the differential diagnosis of liver dysfunction first presenting in the early postpartum period. A case of postpartum hepatitis of auto-immune aetiology is being presented here. It is disease of unknown aetiology, characterised by inflammation of liver (as evidenced by raised serum transaminases, presence of interface hepatitis on histological examination), hypergammaglobulinaemia (> 1.5 times normal), presence of auto-antibodies [(antinuclear antibodies (ANA)], smooth muscle antibody (SMA) and antibody to liver-kidney microsome type 1 (LKM1) in the absence of viral markers ie, hepatitis B (HBsAg) and C (AntiHCV) and excellent response to corticosteroid therapy.

Hepatitis C virus infection can mimic type 1 (antinuclear antibody positive) autoimmune chronic active hepatitis.

Science.gov (United States)

Pawlotsky, J M; Deforges, L; Bretagne, S; André, C; Métreau, J M; Thiers, V; Zafrani, E S; Goossens, M; Duval, J; Mavier, J P

1993-01-01

Hepatitis C virus (HCV) has been shown to induce anti-liver-kidney microsomal-1 (LKM1) antibody positive chronic active hepatitis, simulating type 2 autoimmune chronic active hepatitis. The cases of five patients presenting with features of type 1 (antinuclear antibody positive) autoimmune chronic active hepatitis and extrahepatic autoimmune manifestations, in whom immunosuppressive treatment had no effect on liver disease are presented. In these patients, HCV infection could be shown by the presence in serum of anti-HCV antibodies and HCV-RNA detected by polymerase chain reaction. These cases suggest the following: (a) chronic HCV infection can mimic type 1, as well as type 2, autoimmune chronic active hepatitis; (b) HCV infection might be systematically sought in patients presenting with features of type 1 autoimmune chronic active hepatitis, with special care in patients who are unresponsive to immunosuppressive treatment. Images Figure PMID:7686122

Effect of rat whole-body irradiation on oxidase chain and glucose-6-phosphatase of liver microsome: influence of cysteamine

International Nuclear Information System (INIS)

Bernard, Pierre.

1979-11-01

Three enzymatic systems of the male rat liver endoplasmic reticulum were studied by biochemical methods. Two means of investigation were used: - whole-body irradiation of the animal, - administration of cysteamine. The results obtained are discussed, in view of the functioning of these enzymatic systems, from two viewpoints: - the study of enzymatic radiolesions in relation to the radiobiological effect on the animal, the organ and the sub-cellular organite, - the study of chemical radioprotection. After a 900 R whole-body gamma irradiation a severe drop was observed in the enzymatic activity of two essential elements of the microsome oxydase chain: NADPH cytochrome P450 reductase and ethylmorphine N-demethylation. Glucose 6 phosphatase is also impaired by irradiation. Here it seems that the microsomal protein fraction could be responsible for the change in the enzyme activity. The irradiation effect is therefore not specific to one enzyme. The changes in these enzymatic activities correspond to the different phases of the acute irradiation syndrome which also affects the weight of the experimental animal and of the organ studied. Cysteamine used under chemical radioprotection conditions was found to be especially useful as a means of investigation complementary to the study of enzymatic radiolesions. From the combined action of irradiation and of the radioprotector it was possible to obtain a partial idea of the mechanisms of these radiolesions [fr

Mutagenicity of anthraquinone and hydroxylated anthraquinones in the Ames/Salmonella microsome system.

Science.gov (United States)

Liberman, D F; Fink, R C; Schaefer, F L; Mulcahy, R J; Stark, A A

1982-01-01

The mutagenicity of anthracene, anthraquinone, and four structurally similar compounds of each was evaluated in the Ames/Salmonella microsome assay. Anthraquinone was shown to be mutagenic for strains TA1537, TA1538, and TA98 in the absence of rat liver homogenate. The four anthraquinone derivatives tested were mutagenic for TA1537 exclusively. None of the anthracenes exhibited mutagenic activity. PMID:7103489

Mutagenicity of anthraquinone and hydroxylated anthraquinones in the Ames/Salmonella microsome system.

OpenAIRE

Liberman, D F; Fink, R C; Schaefer, F L; Mulcahy, R J; Stark, A A

1982-01-01

The mutagenicity of anthracene, anthraquinone, and four structurally similar compounds of each was evaluated in the Ames/Salmonella microsome assay. Anthraquinone was shown to be mutagenic for strains TA1537, TA1538, and TA98 in the absence of rat liver homogenate. The four anthraquinone derivatives tested were mutagenic for TA1537 exclusively. None of the anthracenes exhibited mutagenic activity.

An integrated study for the utilization of anthraquinone compounds extract “Heshouwu” In vivo and their comparative metabolism in liver microsomes using UPLC-ESI-Q-TOF/MSn

Directory of Open Access Journals (Sweden)

Sha Chen

2018-01-01

Full Text Available Objective: Anthraquinone (AQ, a major bioactive component of the traditional Chinese medicine HeShouWu, has widespread applications in industry and medicine. The objective of the current study is to explore the differences in the bioavailability of anthraquinones in vivo and the metabolism in liver microsomes. Materials and Methods: In vivo, we used a reliable UPLC-ESI-QqQ-MS/MS method to measure seven AQ compounds in the jugular vein plasma of rats following oral administration of HeShouWu. Furthermore, in order to quantify the bioavailability of AQs in vivo and to further understand the metabolism of these compounds, we compared the in vitro metabolism of AQ in different species with respect to metabolic profiles, the enzymes involved, and catalytic efficiency using liver microsomes from human (HLM, mouse (MLM, rat (RLM, and beagle dog (DLM. Results: We identified two metabolic pathways, including the hydroxylation and glucuronidation of AQ, in the liver microsomes of humans and other species using UPLC-ESI-Q-TOF. We found that substitutions on the AQ ring were crucial to the activity and regioselectivity of its hydroxylation. In general, hydroxylation activity decreased greatly with β-COOH (rhein and enhanced dramatically with β-OH (emodin. We also found that glucuronidation of the compound emodin-8-O-β-D-glucoside acts as the main isoform in AQ hydroxylation in HLM and DLM. Total microsomal intrinsic clearance values for AQ were greatest in mouse microsomes, followed by those in dog, human, and rat microsomes. Conclusion: The absorption of different anthrquinone compounds varied based on the compound structure, the metabolism types and products of anthraquinones in liver microsomes were different in different species. These findings provide vital information for a deeper unuunderstanding of the metabolism of AQs.

The role of hepatic mitochondria in the regulation of glucose metabolism in BHE rats

International Nuclear Information System (INIS)

Kim, M.J.C.

1988-01-01

The interacting effects of dietary fat source and thyroxine treatment on the hepatic mitochondrial function and glucose metabolism were studied. In the first study, three different sources of dietary fatty acids and thyroxine treatment were used to investigate the hepatic mitochondrial thermotropic behavior in two strains of rat. The NIDDM BHE and Sprague-Dawley rats were used. Feeding coconut oil increased serum T 4 levels and T 4 treatment increased serum T 3 levels in the BHE rats. In the mitochondria from BHE rats fed coconut oil and treated with T 4 , the transition temperature disappeared due to a decoupling of succinate supported respiration. This was not observed in the Sprague-Dawley rats. In the second study, two different sources of dietary fat and T 4 treatment were used to investigate hepatic mitochondrial function. Coconut oil feeding increased Ca ++ Mg ++ ATPase and Mg ++ ATPase. T 4 treatment had potentiated this effect. T 4 increased the malate-aspartate shuttle and α-glycerophosphate shuttle activities. In the third study, the glucose turnover rate from D-[ 14 C-U]/[6- 3 H]-glucose and gluconeogeneis from L-[ 14 C-U]-alanine was examined. Dietary fat or T 4 did not affect the glucose mass. T 4 increased the irreversible fractional glucose turnover rate

A relative study of hepatic perfusion and portal vein pressure in rats with liver cirrhosis

International Nuclear Information System (INIS)

Li Jiaping; Yang Jianyong; Chen Wei; Huang Yonghui

2006-01-01

Objective: To evaluate spiral CT perfusion in assessing portal vein pressure in rats with different stages of liver cirrhosis. Methods Seventeen rats with early stage of liver cirrhosis, 18 with intermediate stage, 12 with advanced stage, and 13 healthy rats as a control group were selected and recieved hepatic perfusion on a single-row spiral CT scanner. The parameters of hepatic perfusion were calculated using the deconvolution method. The portal vein pressure was measured by multi-physiographer. Results: (1) In study group, the PVP (portal venous perfusion) and THBP (total hepatic blood perfusion) were negatively correlated with FPP, while positively correlated with the HPI (hepatic perfusion index) and MTT (mean transit time). The FPP had a close relation with PVP. The equation, Y 20.671-3.195X, could be conducted with linear regression analysis. (2) According to the linear regression equation mentioned above, the FPP in 47 rats were 16.090±2.150 cmH 2 0, which was highly correlated with the observed valuel6.108±3.662 cmH 2 O (r=0.823 P<0.01). Conclusion: CT perfusion is a new non-invasive and efficient modality for assessment of the portal pressure in liver cirrhosis in various stages. (authors)

Sub-acute deltamethrin and fluoride toxicity induced hepatic oxidative stress and biochemical alterations in rats.

Science.gov (United States)

Dubey, Nitin; Khan, Adil Mehraj; Raina, Rajinder

2013-09-01

The current study investigated the effects of deltamethrin, fluoride (F(-)) and their combination on the hepatic oxidative stress and consequent alterations in blood biochemical markers of hepatic damage in rats. Significant hepatic oxidative stress and hepatic damage were observed in the toxicant exposed groups. These changes were higher in the deltamethrin-F(-) co-exposure treatment group, depicting a positive interaction between the two chemicals.

FXR agonist obeticholic acid reduces hepatic inflammation and fibrosis in a rat model of toxic cirrhosis

Science.gov (United States)

Verbeke, Len; Mannaerts, Inge; Schierwagen, Robert; Govaere, Olivier; Klein, Sabine; Vander Elst, Ingrid; Windmolders, Petra; Farre, Ricard; Wenes, Mathias; Mazzone, Massimiliano; Nevens, Frederik; van Grunsven, Leo A.; Trebicka, Jonel; Laleman, Wim

2016-01-01

Hepatic inflammation drives hepatic stellate cells (HSC), resulting in liver fibrosis. The Farnesoid-X receptor (FXR) antagonizes inflammation through NF-κB inhibition. We investigated preventive and therapeutic effects of FXR agonist obeticholic acid (OCA) on hepatic inflammation and fibrosis in toxic cirrhotic rats. Cirrhosis was induced by thioacetamide (TAA) intoxication. OCA was given during or after intoxication with vehicle-treated rats as controls. At sacrifice, fibrosis, hemodynamic and biochemical parameters were assessed. HSC activation, cell turn-over, hepatic NF-κB activation, pro-inflammatory and pro-fibrotic cytokines were determined. The effect of OCA was further evaluated in isolated HSC, Kupffer cells, hepatocytes and liver sinusoidal endothelial cells (LSEC). OCA decreased hepatic inflammation and fibrogenesis during TAA-administration and reversed fibrosis in established cirrhosis. Portal pressure decreased through reduced intrahepatic vascular resistance. This was paralleled by decreased expression of pro-fibrotic cytokines (transforming growth-factor β, connective tissue growth factor, platelet-derived growth factor β-receptor) as well as markers of hepatic cell turn-over, by blunting effects of pro-inflammatory cytokines (e.g. monocyte chemo-attractant protein-1). In vitro, OCA inhibited both LSEC and Kupffer cell activation; while HSC remained unaffected. This related to NF-κB inhibition via up-regulated IκBα. In conclusion, OCA inhibits hepatic inflammation in toxic cirrhotic rats resulting in decreased HSC activation and fibrosis. PMID:27634375

Luminol-and lucigenin-amplified chemiluminescence with rat liver microsomes. Kinetics and influence of ascorbic acid, glutathione, dimethylsulfoxide, N-t-butyl-a-phenyl-nitrone, copper-ions and a copper complex, catalase, superoxide dismutase, hexobarbital and aniline.

Science.gov (United States)

Klinger, W; Karge, E; Kretzschmar, M; Rost, M; Schulze, H P; Dargel, R; Reinemann, C; Rein, H

1996-07-01

For the investigation of luminol (LM)-and lucigenin (LC)-amplified chemiluminescence (CL) in rat liver microsomes using both a liquid-scintillation counter (LKB/Wallac 1219 Rackbeta) and a Berthold luminometer (AutoLumat LB 953) optimal incubation mixtures and conditions and basic kinetics have been established. Whereas calibration curves for both LM- and LC-CL are performed with hydrogenperoxide (LC quantum yield is 6.25 fold higher as that of LM), distinct differences were revealed with microsomes, indicating that different reactive oxygen species (ROS) are determined: Both LM- and LC-CL follow the kinetics of enzymatic reactions in terms of dependence on protein and NADPH or NADH concentration, time course, temperature etc., but with differences. LM-CL does not work without addition of Fe2+, whereas LC-CL does. Both copper ions and copper bound in a complex abolish CL, LC-CL being much more sensitive. Isolated cytochrome P-450 (P450) and NADPH P450 reductase from liver of pheno-barbital treated rats alone proved to be inactive in LM-and LC-CL production, whereas te combination 1:1 without and with addition of lipid was highly active in both LM-and LC-CL. Ascorbic acid and glutathione as scavengers diminish both LM- and LC-CL in concentrations higher then 10(5). Dimethyl-sulfoxide (DMSO) was ineffective in LM-CL up to concentrations of 0.2 M, the very high concentration of 2 M diminished LM-CL only to 1/3. LC-CL was diminished starting at concentrations of 100 mM and at 2 M only 10% of maximum LC-CL was observed. The trap substance N-t-butyl-a-phenylnitrone (BNP) also diminished LC-CL more effectively than LM-CL. Clearcut differences were revealed by the addition of catalase and superoxide dismutase: both enzymes diminished LM-CL only, without any influence on LC-CL. Hexobarbital, a potent uncoupler of P450, enhances LM-CL fivefold, whereas LC-CL is barely influenced. Aniline (without uncoupling capability) decreased both LM-and LC-CL increasingly with increasing

[Detection and the production mechanism of antinuclear antibodies (ANA) and anti-liver/kidney microsomal tpe 1 antibodies (anti-LKM1) in patients with chronic hepatitis C].

Science.gov (United States)

Bai, Li; Lu, Hai-Ying; Feng, Zhen-Ru; Yu, Min; Li, Wen-Gang; Gong, Wei-Bo; Zhao, Nu-en-ji-ya; Xu, Xiao-Yuan

2009-08-01

To investigate the prevalence of antinuclear antibodies (ANA) and anti-liver/ kidney microsomal type 1 antibodies (anti-LKM1) in patients with chronic hepatitis C (CHC)and to explore the mechanism of production of these autoantibodies. Serum samples were collected from 360 patients with CHC (case group), 69 patients with chronic hepatitis B (CHB) and 69 patients with autoimmune hepatitis (AIH) (control group). Serum ANA and anti-LKM1 were detected by indirect immunofluorescence (HF) technique and enzyme-linked immunosorbent assay (ELISA), respectively. Multi-factor analysis was performed to explore the correlations of the production of autoantibodies with some factors such as age, sex, viral loads, HCV genotype, biochemical parameters and clinical characteristics. Fifty-four (15%) of 360 patients infected with HCV were positive in autoantibodies. The prevalence of ANA and anti-LKM1 were 12.5% (45/360) and 2.5% (9/ 360), respectively. The positive rate of autoantibodies in patients with CHC was significantly higher than that in patients with CHB (15% vs 2.9%, P = 0.006), but significantly lower than that in patients with AIH (15% vs 47.9%, P 0.05). Autoantibodies related to AIH can be detected in CHC patients; interferon may not induce the production of autoantibodies; it is very likely that HCV infection induces the autoimmune reaction and the production of autoantibodies.

Inhibition of the phospholipid transfer within the organelles of cells in the irradiated rat liver

Energy Technology Data Exchange (ETDEWEB)

Kaznacheev, Yu S; Kolomiytseva, I K [AN SSSR, Pushchino-na-Oke. Inst. Biologicheskoj Fiziki

1975-01-01

Phosphatidyl choline (PC) and phosphatidyl ethanolamine (PE) exchange between different subcellular fractions of liver has been studied in normal rats and 1 hr after gamma-irradiation of rats at a dose of 1200 R. The rate of PC transfer in microsome-mitochondrion and microsome-nucleus systems is 1.5 to 2 times higher than that of PE. Early after irradiation the rates of PE and PC transfer decrease in both microsome-mitochondrion and microsome-nucleus systems.

Alterations by peroxisome proliferators of acyl composition of hepatic phosphatidylcholine in rats, mice and guinea-pigs. Role of stearoyl-CoA desaturase.

Science.gov (United States)

Kawashima, Y; Hirose, A; Kozuka, H

1986-01-01

Rats, mice and guinea-pigs were administered p-chlorophenoxyisobutyric acid (clofibric acid) or 2,2'-(decamethylenedithio)diethanol (tiadenol). The treatments of rats and mice with either clofibric acid or tiadenol increased markedly the activities of stearoyl-CoA desaturase, palmitoyl-CoA chain elongation, 1-acylglycerophosphate (1-acyl-GP) acyltransferase and 1-acylglycerophosphocholine (1-acyl-GPC) acyltransferase, but not 2-acylglycerophosphocholine (2-acyl-GPC) acyltransferase in liver microsomes. The treatment of guinea-pigs with clofibric acid did not cause any change in the activities of these enzymes. The treatment of guinea-pigs with tiadenol caused a slight, but significant, increase in the activities of 1-acyl-GP acyltransferase and 1-acyl-GPC acyltransferase. The treatment of rats and mice with either clofibric acid or tiadenol increased markedly the proportion of 18:1 and decreased greatly the proportion of 18:0 in liver microsomal phosphatidylcholine. However, there is a considerable difference in the effects of the two peroxisome proliferators on the composition of polyunsaturated fatty acids in phosphatidylcholine between rats and mice. The treatment of guinea-pigs with either of the two peroxisome proliferators caused no change in acyl composition of phosphatidylcholine. The possible role of stearoyl-CoA desaturation in the regulation of acyl composition of phosphatidylcholine was discussed. PMID:2874791

Protective effect of Piper betle leaf extract against cadmium-induced oxidative stress and hepatic dysfunction in rats.

Science.gov (United States)

Milton Prabu, S; Muthumani, M; Shagirtha, K

2012-04-01

The present study was undertaken to examine the attenuative effect of Piper betle leaf extract (PBE) against cadmium (Cd) induced oxidative hepatic dysfunction in the liver of rats. Pre-oral supplementation of PBE (200 mg/kg BW) treated rats showed the protective efficacy against Cd induced hepatic oxidative stress. Oral administration of Cd (5 mg/kg BW) for four weeks to rats significantly (P > 0.05) elevated the level of serum hepatic markers such as serum aspartate transaminase (AST), serum alanine transaminase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), gamma-glutamyl transpeptidase (GGT), bilirubin (TBRNs), oxidative stress markers viz., thiobarbituric acid reactive substances (TBARS), lipid hydroperoxides (LOOH), protein carbonyls (PC) and conjugated dienes (CD) and significantly (P > 0.05) reduced the enzymatic antioxidants viz., superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase (GST), glutathione reductase (GR) and glucose-6-phosphate dehydrogenase (G6PD) and non-enzymatic antioxidants Viz., reduced glutathione (GSH), total sulfhydryls (TSH), vitamin C and vitamin E in the liver. Pre-oral supplementation of PBE (200 mg/kg BW) in Cd intoxicated rats, the altered biochemical indices and pathological changes were recovered significantly (P > 0.05) which showed ameliorative effect of PBE against Cd induced hepatic oxidative stress. From the above findings, we suggested that the pre-administration of P. betle leaf extract exhibited remarkable protective effects against cadmium-induced oxidative hepatic injury in rats.

PHOTOMETRIC EVIDENCE FOR THE OSMOTIC BEHAVIOR OF RAT LIVER MICROSOMES

Science.gov (United States)

Tedeschi, Henry; James, Joseph M.; Anthony, William

1963-01-01

Electron microscope observations are consistent with the interpretation that the elements of the endoplasmic reticulum are osmotically active in situ as well as after isolation. More recently, it has been reported that microsomal suspensions equilibrate almost completely with added C14-sucrose and that no osmotic behavior is evident from photometric data. These findings were considered at variance with the electron microscope data. However, equilibration with added label simply attests to a relatively high permeability, and, in addition, the photometric data need not be critical. Osmotic volume changes, measured photometrically, may be masked by concomitant events (e.g., changes in the refractive index of the test solutions at varying osmotic pressures, breakdown of the particles, and agglutination). For these reasons the photometric experiments were repeated. In this work, the reciprocal of optical density of microsomal suspensions was found to vary linearly with the reciprocal of concentration of the medium at constant refractive index. These changes probably correspond to osmotic volume changes, since the effect was found to be (a) independent of substance used and (b) osmotically reversible. The transmission of the suspension was found to vary with the refractive index of the medium, the concentration of particles, and the wavelength of incident light, according to relationships that are similar to or identical with those obtained for mitochondrial suspensions. PMID:14064105

Intrahepatic upregulation of MRTF-A signaling contributes to increased hepatic vascular resistance in cirrhotic rats with portal hypertension.

Science.gov (United States)

Zheng, Lei; Qin, Jun; Sun, Longci; Gui, Liang; Zhang, Chihao; Huang, Yijun; Deng, Wensheng; Huang, An; Sun, Dong; Luo, Meng

2017-06-01

Portal hypertension in cirrhosis is mediated, in part, by increased intrahepatic resistance, reflecting massive structural changes associated with fibrosis and intrahepatic vasoconstriction. Activation of the Rho/MRTF/SRF signaling pathway is essential for the cellular regulatory network of fibrogenesis. The aim of this study was to investigate MRTF-A-mediated regulation of intrahepatic fibrogenesis in cirrhotic rats. Portal hypertension was induced in rats via an injection of CCl 4 oil. Hemodynamic measurements were obtained using a polyethylene PE-50 catheter and pressure transducers. Expression of hepatic fibrogenesis was measured using histological staining. Expression of protein was measured using western blotting. Upregulation of MRTF-A protein expression in the livers of rats with CCl 4 -induced cirrhosis was relevant to intrahepatic resistance and hepatic fibrogenesis in portal hypertensive rats with increased modeling time. Inhibition of MRTF-A by CCG-1423 decelerated hepatic fibrosis, decreased intrahepatic resistance and portal pressure, and alleviated portal hypertension. Increased intrahepatic resistance in rats with CCl 4 -induced portal hypertension is associated with an upregulation of MRTF-A signaling. Inhibition of this pathway in the liver can decrease hepatic fibrosis and intrahepatic resistance, as well as reduce portal pressure in cirrhotic rats with CCl 4 -induced portal hypertension. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Autoantibodies in Autoimmune Hepatitis.

Science.gov (United States)

Muratori, Luigi; Deleonardi, Gaia; Lalanne, Claudine; Barbato, Erica; Tovoli, Alessandra; Libra, Alessia; Lenzi, Marco; Cassani, Fabio; Muratori, Paolo

2015-01-01

The detection of diagnostic autoantibodies such as antinuclear antibodies (ANA), anti-smooth muscle antibodies (SMA), anti-liver/kidney microsomal type 1 (anti-LKM1), anti-liver cytosol type 1 (anti-LC1) and anti-soluble liver antigen (anti-SLA) is historically associated with the diagnosis of autoimmune hepatitis. When autoimmune hepatitis is suspected, the detection of one or any combination of diagnostic autoantibodies, by indirect immunofluorescence or immuno-enzymatic techniques with recombinant antigens, is a pivotal step to reach a diagnostic score of probable or definite autoimmune hepatitis. Diagnostic autoantibodies (ANA, SMA, anti-LKM1, anti-LC1, anti-SLA) are a cornerstone in the diagnosis of autoimmune hepatitis. Other ancillary autoantibodies, associated with peculiar clinical correlations, appear to be assay-dependent and institution-specific, and validation studies are needed. © 2015 S. Karger AG, Basel.

Preventive effects of chronic exogenous growth hormone levels on diet-induced hepatic steatosis in rats

Directory of Open Access Journals (Sweden)

Tian Ya-ping

2010-07-01

Full Text Available Abstract Background Non-alcoholic fatty liver disease (NAFLD, which is characterized by hepatic steatosis, can be reversed by early treatment. Several case reports have indicated that the administration of recombinant growth hormone (GH could improve fatty liver in GH-deficient patients. Here, we investigated whether chronic exogenous GH levels could improve hepatic steatosis induced by a high-fat diet in rats, and explored the underlying mechanisms. Results High-fat diet-fed rats developed abdominal obesity, fatty liver and insulin resistance. Chronic exogenous GH improved fatty liver, by reversing dyslipidaemia, fat accumulation and insulin resistance. Exogenous GH also reduced serum tumour necrosis factor-alpha (TNF-alpha levels, and ameliorated hepatic lipid peroxidation and oxidative stress. Hepatic fat deposition was also reduced by exogenous GH levels, as was the expression of adipocyte-derived adipokines (adiponectin, leptin and resistin, which might improve lipid metabolism and hepatic steatosis. Exogenous GH seems to improve fatty liver by reducing fat weight, improving insulin sensitivity and correcting oxidative stress, which may be achieved through phosphorylation or dephosphorylation of a group of signal transducers and activators of hepatic signal transduction pathways. Conclusions Chronic exogenous GH has positive effects on fatty liver and may be a potential clinical application in the prevention or reversal of fatty liver. However, chronic secretion of exogenous GH, even at a low level, may increase serum glucose and insulin levels in rats fed a standard diet, and thus increase the risk of insulin resistance.

Effects of 4-nonylphenol on oxidant/antioxidant balance system inducing hepatic steatosis in male rat

Directory of Open Access Journals (Sweden)

Ansoumane Kourouma

2015-01-01

Full Text Available An emerging literature suggests that early life exposure to 4-nonylphenol (4-NP, a widespread endocrine disrupting chemical, may increase the risk of metabolic syndrome. In this study, we investigated the hypothesis that intraperitoneal administration of 4-NP induces hepatic steatosis in rat. 24 male Sprague-Dawley rats were administered with 4-NP (0, 2, 10 and 50 mg/kg b.wt in corn oil for 30 days. Liver histology, biochemical analysis and gene expression profiling were examined. After treatment, abnormal liver morphology and function were observed in the 4-NP-treated rat, and significant changes in gene expression an indicator of hepatic steatosis and apoptosis were observed compared with controls. Up-regulated genes involved in apoptosis, hepatotoxity and oxidative stress, increased ROS and decrease of antioxidant enzyme were observed in the 4-NP exposed rat. Extensive fatty accumulation in liver section and elevated serum GOT, GPT, LDH and γ-GT were also observed. Incidence and severity of liver steatosis was scored and taken into consideration (steatosis, ballooning and lobular inflammation. Hepatocytes apoptosis could promote NAFLD progression; Fas/FasL, TNF-α and Caspase-9 mRNA activation were important contributing factors to hepatic steatosis. These findings provide the first evidence that 4-NP affects the gene expression related to liver hepatotoxicity, which is correlated with hepatic steatosis.

Short-term inhalation toxicity of methanol, gasoline, and methanol/gasoline in the rat.

Science.gov (United States)

Poon, R; Chu, I; Bjarnason, S; Vincent, R; Potvin, M; Miller, R B; Valli, V E

1995-01-01

Four- to five-week-old male and female Sprague Dawley rats were exposed to vapors of methanol (2500 ppm), gasoline (3200 ppm), and methanol/gasoline (2500/3200 ppm, 570/3200 ppm) six hours per day, five days per week for four weeks. Control animals were exposed to filtered room air only. Depression in body weight gain and reduced food consumption were observed in male rats, and increased relative liver weight was detected in rats of both sexes exposed to gasoline or methanol/gasoline mixtures. Rats of both sexes exposed to methanol/gasoline mixtures had increased relative kidney weight and females exposed to gasoline and methanol/gasoline mixtures had increased kidney weight. Decreased serum glucose and cholesterol were detected in male rats exposed to gasoline and methanol/gasoline mixtures. Decreased hemoglobin was observed in females inhaling vapors of gasoline and methanol/gasoline at 570/3200 ppm. Urine from rats inhaling gasoline or methanol/gasoline mixtures had up to a fourfold increase in hippuric acid, a biomarker of exposure to the toluene constituent of gasoline, and up to a sixfold elevation in ascorbic acid, a noninvasive biomarker of hepatic response. Hepatic mixed-function oxidase (aniline hydroxylase, aminopyrine N-demethylase and ethoxyresorufin O-deethylase) activities and UDP-glucuronosyltransferase activity were elevated in rats exposed to gasoline and methanol/gasoline mixtures. Histopathological changes were confined to very mild changes in the nasal passages and in the uterus, where decreased incidence or absence of mucosal and myometrial eosinophilia was observed in females inhaling gasoline and methanol/gasoline at 570/3200 ppm. It was concluded that gasoline was largely responsible for the adverse effects, the most significant of which included depression in weight gain in the males, increased liver weight and hepatic microsomal enzyme activities in both sexes, and suppression of uterine eosinophilia. No apparent interactive effects

Anticuerpos anti LKM-1 y crioglobulinemia en hepatitis crónica autoinmune y por virus C de la hepatitis

OpenAIRE

Jirón V,M. Isabel; Ardiles S,Adriana; Parra B,M Adriana; Orellana V,Juana

2000-01-01

Background: Anti liver kidney microsome antibodies (LKM-1) have been recently incorporated to the study and classification of chronic autoimmune hepatitis (HC-A1). The presence of anti LKM-1 antibodies and essential cryoglobulinemia is frequent in virus C associated chronic hepatitis (HC-VC). Aim: To study the frequency of anti LKM-1 antibodies and cryoglobulin levels in patients with HC-AI, HC-VC and cryptogenic cirrhosis. Patients and methods: Forty two patients were studied. Nineteen adult...

Dietary supplementation of blueberry juice enhances hepatic expression of metallothionein and attenuates liver fibrosis in rats.

Directory of Open Access Journals (Sweden)

Yuping Wang

Full Text Available To investigate the effect of blueberry juice intake on rat liver fibrosis and its influence on hepatic antioxidant defense.Rabbiteye blueberry was used to prepare fresh juice to feed rats by daily gastric gavage. Dan-shao-hua-xian capsule (DSHX was used as a positive control for liver fibrosis protection. Liver fibrosis was induced in male Sprague-Dawley rats by subcutaneous injection of CCl4 and feeding a high-lipid/low-protein diet for 8 weeks. Hepatic fibrosis was evaluated by Masson staining. The expression of α-smooth muscle actin (α-SMA and collagen III (Col III were determined by immunohistochemical techniques. The activities of superoxide dismutase (SOD and malondialdehyde (MDA in liver homogenates were determined. Metallothionein (MT expression was detected by real-time RT-PCR and immunohistochemical techniques.Blueberry juice consumption significantly attenuates CCl4-induced rat hepatic fibrosis, which was associated with elevated expression of metallothionein (MT, increased SOD activity, reduced oxidative stress, and decreased levels of α-SMA and Col III in the liver.Our study suggests that dietary supplementation of blueberry juice can augment antioxidative capability of the liver presumably via stimulating MT expression and SOD activity, which in turn promotes HSC inactivation and thus decreases extracellular matrix collagen accumulation in the liver, and thereby alleviating hepatic fibrosis.

Hepatic cysteamine and non-protein sulfhydryl levels following cystamine or cysteamine treatment of galactosamine-poisoned rats

International Nuclear Information System (INIS)

MacDonald, J.R.; Gandolfi, A.J.; Sipes, I.G.

1985-01-01

Hepatic cysteamine and non-protein sulfhydryl (NPSH) levels were determined in galactosamine (GAL)-poisoned rats following hepatoprotective cystamine or cysteamine treatments to determine whether alterations of hepatic NPSH status could contribute to their observed protective actions. D(+)-Galactosamine HC1 (400 mg/kg, ip) was administered to male Sprague-Dawley rats at 8 pm. Cystamine diHC1 (300 mg/kg, po) or cysteamine HC1 (170 mg/kg, ip) were administered 12 hr after GAL. Hepatic NPSH levels were determined using Ellman's reagent. Hepatic cysteamine levels were determined by separating NPSH Ellman's derivatives by reversed phase HPLC. Cystamine and cysteamine caused transient elevation of NPSH levels of 1-2 nanomoles/mg liver which correlated with the presence of 1-2 nanomoles of cysteamine/mg liver. However, neither cystamine nor cysteamine prevented NPSH levels from falling to 3 nanomoles/mg tissue 24 hr after GAL. Hepatoprotective treatments did not affect long term NPSH status in GAL-poisoned rats. However, transient NPSH increases, due to the intrahepatic presence of cysteamine, may contribute to the therapeutic effects of these hepatoprotective agents

Pharmacokinetic study of isocorynoxeine metabolites mediated by cytochrome P450 enzymes in rat and human liver microsomes.

Science.gov (United States)

Zhao, Lizhu; Zang, Bin; Qi, Wen; Chen, Fangfang; Wang, Haibo; Kano, Yoshihiro; Yuan, Dan

2016-06-01

Isocorynoxeine (ICN) is one of the major bioactive tetracyclic oxindole alkaloids found in Uncaria rhynchophylla (Miq.) Jacks. that is widely used for the treatment of hypertension, vascular dementia, and stroke. The present study was undertaken to assess the plasma pharmacokinetic characteristics of major ICN metabolites, and the role of simulated gastric and intestinal fluid (SGF and SIF), human and rat liver microsomes (HLMs and RLMs), and seven recombinant human CYP enzymes in the major metabolic pathway of ICN. A rapid, sensitive and accurate UHPLC/Q-TOF MS method was validated for the simultaneous determination of ICN and its seven metabolites in rat plasma after oral administration of ICN at 40mg/kg. It was found that 18.19-dehydrocorynoxinic acid (DCA) and 5-oxoisocorynoxeinic acid (5-O-ICA) were both key and predominant metabolites, rather than ICN itself, due to the rapid and extensive metabolism of ICN in vivo. The further study indicated that ICN was mainly metabolized in human or rat liver, and CYPs 2C19, 3A4 and 2D6 were the major enzymes responsible for the biotransformation of ICN to DCA and 5-O-ICA in human. These findings are of significance in understanding of the pharmacokinetic nature of tetracyclic oxindole alkaloids, and provide helpful information for the clinical co-administration of the herbal preparations containing U. rhynchophylla with antihypertensive drugs that are mainly metabolized by CYP3A4 and CYP2C19. Copyright © 2016 Elsevier B.V. All rights reserved.

Memantine, a noncompetitive NMDA receptor antagonist improves hyperammonemia-induced encephalopathy and acute hepatic encephalopathy in rats

NARCIS (Netherlands)

Vogels, B. A.; Maas, M. A.; Daalhuisen, J.; Quack, G.; Chamuleau, R. A.

1997-01-01

The aim of this study was to investigate the possible role of N-methyl-D-aspartate (NMDA)-receptor overactivity in two different experimental rat models of encephalopathy: subacute encephalopathy caused by severe hyperammonemia in portacaval-shunted rats (AI-PCS rats) and acute hepatic

Morphology and Molecular Mechanisms of Hepatic Injury in Rats under Simulated Weightlessness and the Protective Effects of Resistance Training.

Directory of Open Access Journals (Sweden)

Fang Du

Full Text Available This study investigated the effects of long-term simulated weightlessness on liver morphology, enzymes, glycogen, and apoptosis related proteins by using two-month rat-tail suspension model (TS, and liver injury improvement by rat-tail suspension with resistance training model (TS&RT. Microscopically the livers of TS rats showed massive granular degeneration, chronic inflammation, and portal fibrosis. Mitochondrial and endoplasmic reticulum swelling and loss of membrane integrity were observed by transmission electron microscopy (TEM. The similar, but milder, morphological changes were observed in the livers of TS&RT rats. Serum biochemistry analysis revealed that the levels of alanine aminotransferase (ALT and aspartate aminotransferase (AST were significantly higher (p<0.05 in TS rats than in controls. The levels of ALT and AST in TS&RT rats were slightly lower than in RT rats, but they were insignificantly higher than in controls. However, both TS and TS&RT rats had significantly lower levels (p<0.05 of serum glucose and hepatic glycogen than in controls. Immunohistochemistry demonstrated that the expressions of Bax, Bcl-2, and active caspase-3 were higher in TS rats than in TS&RT and control rats. Real-time polymerase chain reaction (real-time PCR showed that TS rats had higher mRNA levels (P < 0.05 of glucose-regulated protein 78 (GRP78 and caspase-12 transcription than in control rats; whereas mRNA expressions of C/EBP homologous protein (CHOP and c-Jun N-terminal kinase (JNK were slightly higher in TS rats. TS&RT rats showed no significant differences of above 4 mRNAs compared with the control group. Our results demonstrated that long-term weightlessness caused hepatic injury, and may trigger hepatic apoptosis. Resistance training slightly improved hepatic damage.

Acute Ethanol Gavage Attenuates Hemorrhage/Resuscitation-Induced Hepatic Oxidative Stress in Rats

Directory of Open Access Journals (Sweden)

B. Relja

2012-01-01

Full Text Available Acute ethanol intoxication increases the production of reactive oxygen species (ROS. Hemorrhagic shock with subsequent resuscitation (H/R also induces ROS resulting in cellular and hepatic damage in vivo. We examined the role of acute ethanol intoxication upon oxidative stress and subsequent hepatic cell death after H/R. 14 h before H/R, rats were gavaged with single dose of ethanol or saline (5 g/kg, EtOH and ctrl; H/R_EtOH or H/R_ctrl, resp.. Then, rats were hemorrhaged to a mean arterial blood pressure of 30±2 mmHg for 60 min and resuscitated. Two control groups underwent surgical procedures without H/R (sham_ctrl and sham_EtOH, resp.. Liver tissues were harvested at 2, 24, and 72 h after resuscitation. EtOH-gavage induced histological picture of acute fatty liver. Hepatic oxidative (4-hydroxynonenal, 4-HNE and nitrosative (3-nitrotyrosine, 3-NT stress were significantly reduced in EtOH-gavaged rats compared to controls after H/R. Proapoptotic caspase-8 and Bax expressions were markedly diminished in EtOH-gavaged animals compared with controls 2 h after resuscitation. EtOH-gavage increased antiapoptotic Bcl-2 gene expression compared with controls 2 h after resuscitation. iNOS protein expression increased following H/R but was attenuated in EtOH-gavaged animals after H/R. Taken together, the data suggest that acute EtOH-gavage may attenuate H/R-induced oxidative stress thereby reducing cellular injury in rat liver.

Modulatory role of kolaviron in phenytoin-induced hepatic and testicular dysfunctions in Wistar rats.

Science.gov (United States)

Owoeye, Olatunde; Adedara, Isaac A; Adeyemo, Oluwatobi A; Bakare, Oluwafemi S; Egun, Christa; Farombi, Ebenezer O

2015-03-01

Phenytoin, an anticonvulsant agent used for the treatment of epilepsy has been reported to exhibit toxic side effects on the liver and testes. The present study investigated the protective effects of kolaviron (KV, a bioflavonoid from Garcinia kola seeds) against hepatic and testicular damage in rats exposed to phenytoin. The study consisted of four groups of six rats per group. Group I rats received 2 mL/kg of corn alone while group II received 75 mg/kg of phenytoin (PHT) alone. Groups III and IV were co-treated with kolaviron (200 mg/kg KV) and vitamin E (500 mg/kg VTE), respectively, for 14 days. The antioxidant status, hepatic and reproductive functional parameters were subsequently determined. PHT treatment significantly (p < 0.05) increased superoxide dismutase (SOD) and catalase (CAT) activities, elevated lipid peroxidation (LPO) and hydrogen peroxide (H2O2) levels along with significant reduction in the hepatic and testicular levels of glutathione (GSH). Moreover, PHT exposure elicited significant increases in alkaline phosphatase (ALP) and aspartate aminotransferase (AST) levels. The significant reduction in seminal epithelium thickness and the diameter of seminiferous tubules was accompanied with marked decrease in sperm motility, sperm count, and viability in PHT-treated rats. However, antioxidant status and the functional indices of liver and testes were restored to near control levels in rats co-treated with KV and VTE. In conclusion, KV and VTE protect the liver and testes against functional impairment due to PHT treatment.

Effects of Lactobacillus fermented soymilk and soy yogurt on hepatic lipid accumulation in rats fed a cholesterol-free diet.

Science.gov (United States)

Kitawaki, Ryoko; Nishimura, Yuko; Takagi, Naohiro; Iwasaki, Mitsuhiro; Tsuzuki, Kimiko; Fukuda, Mitsuru

2009-07-01

We examined the effects of lactic acid fermented soymilk, in which part of the soymilk was replaced with okara (soy yogurt), on plasma and hepatic lipid profiles in rats fed a cholesterol-free diet. Additionally, we investigated the effects of soy yogurt on hepatic gene expression in rats using DNA microarray analysis. Male Sprague-Dawley rats aged 5 weeks (n=5/group) were fed a control diet (AIN-93) or a test diet in which 20% of the diet was replaced by soy yogurt for 7 weeks. Soy yogurt consumption did not affect body weight or adipose tissue weight as compared with control diet. In the soy yogurt group, the liver weight and hepatic triglyceride content were significantly lower than the control group, and the level of plasma cholesterol was also lower. Furthermore, DNA microarray analysis indicated that soy yogurt ingestion down-regulated the expression of the SREBP-1 gene and enzymes related to lipogenesis in the rat liver, while expression of beta-oxidation-related genes was up-regulated. These results suggest that soy yogurt is beneficial in preventing hepatic lipid accumulation in rats.

Significance of glucagon for insulin secretion and hepatic glycogenolysis during exercise in rats

DEFF Research Database (Denmark)

Richter, Erik; Galbo, H; Holst, J J

1981-01-01

The significance of glucagon and of the sympatho-adrenal system for insulin secretion and hepatic glycogen depletion during exercise was studied. Male rats were either adrenodemedullated and chemically sympathectomized with 6-hydroxydopamine (SX) or sham-treated (C). During light ether anesthesia......, cardiac blood for glucose analysis and a biopsy of the liver were obtained, and either antigen-stripped glucagon antibodies (A) or control gamma globulins (N) in saline were injected through the cardiac cannula. Subsequently, the rats swam in tepid water (33-34 degree C) for 100 minutes with a tail weight...... attached (2% of body weight). Then cardiac blood was drawn for analysis of glucose, insulin and glucagon, and a sample of the liver was collected. In both CA and CN rats, the blood glucose concentration tended to increase (p less than 0.1) during exercise, whereas hepatic glycogen depletion and the plasma...

Comparative pharmacokinetics and tissue distribution profiles of lignan components in normal and hepatic fibrosis rats after oral administration of Fuzheng Huayu recipe.

Science.gov (United States)

Yang, Tao; Liu, Shan; Zheng, Tian-Hui; Tao, Yan-Yan; Liu, Cheng-Hai

2015-05-26

Fuzheng Huayu recipe (FZHY) is formulated on the basis of Chinese medicine theory in treating liver fibrosis. To illuminate the influence of the pathological state of liver fibrosis on the pharmacokinetics and tissue distribution profiles of lignan components from FZHY. Male Wistar rats were randomly divided into normal group and Hepatic fibrosis group (induced by dimethylnitrosamine). Six lignan components were detected and quantified by ultrahigh performance liquid chromatography-tandem mass spectrometry(UHPLC-MS/MS)in the plasma and tissue of normal and hepatic fibrosis rats. A rapid, sensitive and convenient UHPLC-MS/MS method has been developed for the simultaneous determination of six lignan components in different rat biological samples successfully. After oral administration of FZHY at a dose of 15g/kg, the pharmacokinetic behaviors of schizandrin A (SIA), schizandrin B (SIB), schizandrin C (SIC), schisandrol A (SOA), Schisandrol B (SOB) and schisantherin A (STA) have been significantly changed in hepatic fibrosis rats compared with the normal rats, and their AUC(0-t) values were increased by 235.09%, 388.44%, 223.30%, 669.30%, 295.08% and 267.63% orderly (Pdistribution results showed the amount of SIA, SIB, SOA and SOB were significant increased in heart, lung, spleen and kidney of hepatic fibrosis rats compared with normal rats at most of the time point (Pdistribution of lignan components in normal and hepatic fibrosis rats. The hepatic fibrosis could alter the pharmacokinetics and tissue distribution properties of lignan components in rats after administration of FZHY. The results might be helpful for guide the clinical application of this medicine. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Altered carbohydrate, lipid, and xenobiotic metabolism by liver from rats flown on Cosmos 1887

Science.gov (United States)

Merrill, A. H. Jr; Hoel, M.; Wang, E.; Mullins, R. E.; Hargrove, J. L.; Jones, D. P.; Popova, I. A.; Merrill AH, J. r. (Principal Investigator)

1990-01-01

To determine the possible biochemical effects of prolonged weightlessness on liver function, samples of liver from rats that had flown aboard Cosmos 1887 were analyzed for protein, glycogen, and lipids as well as the activities of a number of key enzymes involved in metabolism of these compounds and xenobiotics. Among the parameters measured, the major differences were elevations in the glycogen content and hydroxymethylglutaryl-CoA (HMG-CoA) reductase activities for the rats flown on Cosmos 1887 and decreases in the amount of microsomal cytochrome P-450 and the activities of aniline hydroxylase and ethylmorphine N-demethylase, cytochrome P-450-dependent enzymes. These results support the earlier finding of differences in these parameters and suggest that altered hepatic function could be important during spaceflight and/or the postflight recovery period.

Dietary Supplementation of Blueberry Juice Enhances Hepatic Expression of Metallothionein and Attenuates Liver Fibrosis in Rats

Science.gov (United States)

Wang, Yuping; Cheng, Mingliang; Zhang, Baofang; Nie, Fei; Jiang, Hongmei

2013-01-01

Aim To investigate the effect of blueberry juice intake on rat liver fibrosis and its influence on hepatic antioxidant defense. Methods Rabbiteye blueberry was used to prepare fresh juice to feed rats by daily gastric gavage. Dan-shao-hua-xian capsule (DSHX) was used as a positive control for liver fibrosis protection. Liver fibrosis was induced in male Sprague-Dawley rats by subcutaneous injection of CCl4 and feeding a high-lipid/low-protein diet for 8 weeks. Hepatic fibrosis was evaluated by Masson staining. The expression of α-smooth muscle actin (α-SMA) and collagen III (Col III) were determined by immunohistochemical techniques. The activities of superoxide dismutase (SOD) and malondialdehyde (MDA) in liver homogenates were determined. Metallothionein (MT) expression was detected by real-time RT-PCR and immunohistochemical techniques. Results Blueberry juice consumption significantly attenuates CCl4-induced rat hepatic fibrosis, which was associated with elevated expression of metallothionein (MT), increased SOD activity, reduced oxidative stress, and decreased levels of α-SMA and Col III in the liver. Conclusion Our study suggests that dietary supplementation of blueberry juice can augment antioxidative capability of the liver presumably via stimulating MT expression and SOD activity, which in turn promotes HSC inactivation and thus decreases extracellular matrix collagen accumulation in the liver, and thereby alleviating hepatic fibrosis. PMID:23554912

Liver/kidney microsomal antibody type 1 targets CYP2D6 on hepatocyte plasma membrane.

Science.gov (United States)

Muratori, L; Parola, M; Ripalti, A; Robino, G; Muratori, P; Bellomo, G; Carini, R; Lenzi, M; Landini, M P; Albano, E; Bianchi, F B

2000-04-01

Liver/kidney microsomal antibody type 1 (LKM1) is the marker of type 2 autoimmune hepatitis (AIH) and is detected in up to 6% of patients with hepatitis C virus (HCV) infection. It recognises linear and conformational epitopes of cytochrome P450IID6 (CYP2D6) and may have liver damaging activity, provided that CYP2D6 is accessible to effector mechanisms of autoimmune attack. The presence of LKM1 in the plasma membrane was investigated by indirect immunofluorescence and confocal laser microscopy of isolated rat hepatocytes probed with 10 LKM1 positive sera (five from patients with AIH and five from patients with chronic HCV infection) and a rabbit polyclonal anti-CYP2D6 serum. Serum from both types of patient stained the plasma membrane of non-permeabilised cells, where the fluorescent signal could be visualised as discrete clumps. Conversely, permeabilised hepatocytes showed diffuse submembranous/cytoplasmic staining. Adsorption with recombinant CYP2D6 substantially reduced plasma membrane staining and LKM1 immunoblot reactivity. Plasma membrane staining of LKM1 colocalised with that of anti-CYP2D6. Immunoprecipitation experiments showed that a single 50 kDa protein recognised by anti-CYP2D6 can be isolated from the plasma membrane of intact hepatocytes. AIH and HCV related LKM1 recognise CYP2D6 exposed on the plasma membrane of isolated hepatocytes. This observation supports the notion that anti-CYP2D6 autoreactivity may be involved in the pathogenesis of liver damage.

Effect of selected natural products, thioproline and pegasys on hepatic platelet activating factor (PAF) in CCL4-induced hepatic fibrosis in rats

International Nuclear Information System (INIS)

Badria, Farid A.

2007-01-01

This study aimed to estimate hepatic levels of platelet activating factor (PAF) in liver fibrosis induced by CCl4 in rats. A group of selected natural products; boswellic acids, curcumin and glycrrhizin (preparation named OMNI; a drug under clinical trials for treatment of hepatitis C virus), Mirazid (a commercially available schistomicidal drug), Thioproline (a commercially available hepatoprotective agent) and Pegasys (peg interferon alpha-2a; a commercially available therapy for treatment of Hepatitis C virus) were examined for their effect on hepatic PAF groups each comprised 9 rats. Group 1 was treated only with CCl4, group 2 to 5 were treated with OMNI, Mirazid, Thioproline and Pegasys, respectively whereas the 6th group was the normal control group (with no treatment, except an injection of the vehicle). Liver damage was induced in all groups except normal control group (groups 1 to 5) by i.p. injection of 40% CCl4 in corn oil (0.375 ml/kg) 3 times a week for 3 weeks. One week after CCl4 intoxication, all tested drugs were injected i.p. daily for 3 weeks. Hepatic PAF concentration was estimated by HPTLC (high performance thin layer chromatography), while levels of serum transminases (ALT, AST), hepatic hydroxyproline (as marker of liver fibrosis), serum malondialdehyde and catalase (as markers of oxidative stress) were estimated sepctrophotometrically. The hepatic PAF levels were significantly higher in CCl4 group (24.24+-2.01 pmol equiv. /mg) (p<0.001). Treatment with OMNI, Mirazid, Thioproline and Pegasys reduced hepatic PAF significantly to be 11.84+-0.22, 14.5+-1.00, 13.17+-0, 54 and 14.26+-1.09pmol equiv. /mg respectively. This study may add further rational to the anti-fibrotic activity of the tested drugs via reduction of hepatic PAF. (author)

Identification and characterization of vilazodone metabolites in rats and microsomes by ultrahigh-performance liquid chromatography/quadrupole time-of-flight tandem mass spectrometry.

Science.gov (United States)

Chavan, Balasaheb B; Kalariya, Pradipbhai D; Tiwari, Shristy; Nimbalkar, Rakesh D; Garg, Prabha; Srinivas, R; Talluri, M V N Kumar

2017-12-15

Vilazodone is a selective serotonin reuptake inhibitor (SSRI) used for the treatment of major depressive disorder (MDD). An extensive literature search found few reports on the in vivo and in vitro metabolism of vilazodone. Therefore, we report a comprehensive in vivo and in vitro metabolic identification and structural characterization of vilazodone using ultrahigh-performance liquid chromatography/quadrupole time-of-flight tandem mass spectrometry (UPLC/Q-TOF/MS/MS) and in silico toxicity study of the metabolites. To identify in vivo metabolites of vilazodone, blood, urine and faeces samples were collected at different time intervals starting from 0 h to 48 h after oral administration of vilazodone to Sprague-Dawley rats. The in vitro metabolism study was conducted with human liver microsomes (HLM) and rat liver microsomes (RLM). The samples were prepared using an optimized sample preparation approach involving protein precipitation followed by solid-phase extraction. The metabolites have been identified and characterized by using LC/ESI-MS/MS. A total of 12 metabolites (M1-M12) were identified in in vivo and in vitro matrices and characterized by LC/ESI-MS/MS. The majority of the metabolites were observed in urine, while a few metabolites were present in faeces and plasma. Two metabolites were observed in the in vitro study. A semi-quantitative study based on percentage counts shows that metabolites M11, M6 and M8 were observed in higher amounts in urine, faeces and plasma, respectively. The structures of all the 12 metabolites were elucidated by using LC/ESI-MS/MS. The study suggests that vilazodone was metabolized via hydroxylation, dihydroxylation, glucuronidation, oxidative deamination, dealkylation, dehydrogenation and dioxidation. All the metabolites were screened for toxicity using an in silico tool. Copyright © 2017 John Wiley & Sons, Ltd.

Exposure to a northern contaminant mixture (NCM alters hepatic energy and lipid metabolism exacerbating hepatic steatosis in obese JCR rats.

Directory of Open Access Journals (Sweden)

Ryan J Mailloux

Full Text Available Non-alcoholic fatty liver disease (NAFLD, defined by the American Liver Society as the buildup of extra fat in liver cells that is not caused by alcohol, is the most common liver disease in North America. Obesity and type 2 diabetes are viewed as the major causes of NAFLD. Environmental contaminants have also been implicated in the development of NAFLD. Northern populations are exposed to a myriad of persistent organic pollutants including polychlorinated biphenyls, organochlorine pesticides, flame retardants, and toxic metals, while also affected by higher rates of obesity and alcohol abuse compared to the rest of Canada. In this study, we examined the impact of a mixture of 22 contaminants detected in Inuit blood on the development and progression of NAFLD in obese JCR rats with or without co-exposure to 10% ethanol. Hepatosteatosis was found in obese rat liver, which was worsened by exposure to 10% ethanol. NCM treatment increased the number of macrovesicular lipid droplets, total lipid contents, portion of mono- and polyunsaturated fatty acids in the liver. This was complemented by an increase in hepatic total cholesterol and cholesterol ester levels which was associated with changes in the expression of genes and proteins involved in lipid metabolism and transport. In addition, NCM treatment increased cytochrome P450 2E1 protein expression and decreased ubiquinone pool, and mitochondrial ATP synthase subunit ATP5A and Complex IV activity. Despite the changes in mitochondrial physiology, hepatic ATP levels were maintained high in NCM-treated versus control rats. This was due to a decrease in ATP utilization and an increase in creatine kinase activity. Collectively, our results suggest that NCM treatment decreases hepatic cholesterol export, possibly also increases cholesterol uptake from circulation, and promotes lipid accumulation and alters ATP homeostasis which exacerbates the existing hepatic steatosis in genetically obese JCR rats with

Hepatic arachidonic acid metabolism is disrupted after hexachlorobenzene treatment

International Nuclear Information System (INIS)

Billi de Catabbi, Silvia C.; Faletti, Alicia; Fuentes, Federico; San Martin de Viale, Leonor C.; Cochon, Adriana C.

2005-01-01

Hexaclorobenzene (HCB), one of the most persistent environmental pollutants, can cause a wide range of toxic effects including cancer in animals, and hepatotoxicity and porphyria both in humans and animals. In the present study, liver microsomal cytochrome P450 (CYP)-dependent arachidonic acid (AA) metabolism, hepatic PGE production, and cytosolic phospholipase A 2 (cPLA 2 ) activity were investigated in an experimental model of porphyria cutanea tarda induced by HCB. Female Wistar rats were treated with a single daily dose of HCB (100 mg kg -1 body weight) for 5 days and were sacrificed 3, 10, 17, and 52 days after the last dose. HCB treatment induced the accumulation of hepatic porhyrins from day 17 and increased the activities of liver ethoxyresorufin O-deethylase (EROD), methoxyresorufin O-demethylase (MROD), and aminopyrine N-demethylase (APND) from day 3 after the last dose. Liver microsomes from control and HCB-treated rats generated, in the presence of NADPH, hydroxyeicosatetraenoic acids (HETEs), epoxyeicosatrienoic acids (EETs), 11,12-Di HETE, and ω-OH/ω-1-OH AA. HCB treatment caused an increase in total NADPH CYP-dependent AA metabolism, with a higher response at 3 days after the last HCB dose than at the other time points studied. In addition, HCB treatment markedly enhanced PGE production and release in liver slices. This HCB effect was time dependent and reached its highest level after 10 days. At this time cPLA 2 activity was shown to be increased. Unexpectedly, HCB produced a significant decrease in cPLA 2 activity on the 17th and 52nd day. Our results demonstrated for the first time that HCB induces both the cyclooxygenase and CYP-dependent AA metabolism. The effects of HCB on AA metabolism were previous to the onset of a marked porphyria and might contribute to different aspects of HCB-induced liver toxicity such as alterations of membrane fluidity and membrane-bound protein function. Observations also suggested that a possible role of cPLA 2 in

Hepatic injury after whole-liver irradiation in the rat

International Nuclear Information System (INIS)

Geraci, J.P.; Jackson, K.L.; Mariano, M.S.; Leitch, J.M.

1985-01-01

Radiation-induced hepatic injury in rats, which is characterized by marked ascites accompanied by liver necrosis, fibrosis, and vein lesions, is described in this study. These adverse sequelae are produced within 30 days after irradiation if there is surgical removal of two-thirds of the liver immediately after whole-liver irradiation. The LD/sub 50/30/ day and median survival time after liver irradiation and two-thirds partial hepatectomy is 24 Gy and 17 days, respectively. Death is preceded by reduction in liver function as measured by [ 131 I]-labeled rose bengal clearance. Prior to death, liver sepsis and endotoxemia were detected in most irradiated, partially hepatectomized animals. Pretreatment of the animals with endotoxin and/or antibiotic decontamination of the GI tract resulted in increased survival time, but no irradiated, partially hepatectomized animal survived beyond 63 days. This suggests that sepsis and endotoxemia resulting from the bacteria in the intestine are the immediate cause of death after 30-Gy liver irradiation and partial hepatectomy. It is concluded that the hepatectomized rat model is an economical and scientifically manageable experimental system to study a form of radiation hepatitis that occurs in compromised human livers

Saccharomyces boulardii ameliorates clarithromycin- and methotrexate-induced intestinal and hepatic injury in rats.

Science.gov (United States)

Duman, Deniz Güney; Kumral, Zarife Nigâr Özdemir; Ercan, Feriha; Deniz, Mustafa; Can, Güray; Cağlayan Yeğen, Berrak

2013-08-28

Saccharomyces boulardii is a probiotic used for the prevention of antibiotic-associated diarrhoea. We aimed to investigate whether S. boulardii could alter the effects of clarithromycin (CLA) and methotrexate (MTX) on oro-caecal intestinal transit and oxidative damage in rats. Rats were divided into two groups receiving a single dose of MTX (20 mg/kg) or CLA (20 mg/kg per d) for 1 week. Groups were treated with either saline or S. boulardii (500 mg/kg) twice per d throughout the experiment. The control group was administered only saline. Following decapitation, intestinal transit and inflammation markers of glutathione (GSH), malondialdehyde and myeloperoxidase were measured in intestinal and hepatic tissues. CLA and MTX increased intestinal transit, while S. boulardii treatment slowed down CLA-facilitated transit back to control level. Both MTX and CLA increased lipid peroxidation while depleting the antioxidant GSH content in the hepatic and ileal tissues. Conversely, lipid peroxidation was depressed and GSH levels were increased in the ileal and hepatic tissues of S. boulardii-treated rats. Increased ileal neutrophil infiltration due to MTX and CLA treatments was also reduced by S. boulardii treatment. Histological analysis supported that S. boulardii protected intestinal tissues against the inflammatory effects of both agents. These findings suggest that S. boulardii ameliorates intestinal injury and the accompanying hepatic inflammation by supporting the antioxidant state of the tissues and by inhibiting the recruitment of neutrophils. Moreover, a preventive effect on MTXinduced toxicity is a novel finding of S. boulardii, proposing it as an adjunct to chemotherapy regimens.

Autoimmune hepatitis-specific antibodies against soluble liver antigen and liver cytosol type 1 in patients with chronic viral hepatitis

OpenAIRE

Rigopoulou, Eirini I; Mytilinaiou, Maria; Romanidou, Ourania; Liaskos, Christos; Dalekos, George N

2007-01-01

Background Non-organ specific autoantibodies are highly prevalent in patients with chronic hepatitis C (HCV). Among them, anti-liver kidney microsomal type 1 (LKM1) antibody – the serological marker of type 2 autoimmune hepatitis (AIH-2)- is detected in up to 11% of the HCV-infected subjects. On the other hand, anti-liver cytosol type 1 antibodies (anti-LC1) – either in association with anti-LKM1, or in isolation- and anti-soluble liver antigen antibodies (anti-SLA) have been considered as us...

Selective inhibition by chloramphenicol of pregnenolone-16 α-carbonitrile-inducible rat liver cytochrome P-450 isozymes

International Nuclear Information System (INIS)

Graves, P.E.; Kaminsky, L.S.; Halpert, J.

1986-01-01

Pregnenolone-16 α-carbonitrile (PCN) has been shown to induce, in male rats, cytochrome P-450 isozymes responsible for the formation of R-10-hydroxywarfarin and R-dehydrowarfarin. Antibodies to the major PCN-inducible isozyme (PB/PCN-E) inhibit both activities in microsomal preparations. Recently the authors have shown that PCN treatment of female rats also induces the formation of both R-warfarin metabolites. However, in both sexes chloramphenicol (CAP) treatment selectively inhibits only the rate of formation of the R-dehydrowarfarin. A decrease in microsomal P-450 content occurs after in vivo administration of CAP to PCN-treated rats of both sexes. This is in contrast to the lack of effect of CAP on P-450 levels in phenobarbital-treated rats. Covalent binding of 14 C-CAP to microsomal protein in vitro was increased 3 to 4-fold following PCN treatment. Chromatographic evidences suggests the presence of at least two PCN-induced isozymes of similar molecular weights in both male and female rat liver microsomes. These data are consistent with the multiplicity of PCN-inducible P-450 in rat liver

Chromatographic separation of piracetam and its metabolite in a mixture of microsomal preparations, followed by an MS/MS analysis.

Science.gov (United States)

Sahu, Kapendra; Siddiqui, Anees A; Shaharyar, Mohammad; Ahmad, Niyaz; Anwar, Mohammad; Ahmad, Farhan J

2013-07-01

A rapid bioanalytical method was evaluated for the simultaneous determination of piracetam and its metabolite (M1) in human microsomal preparations by fast ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS). In addition, a validated method of M1 in rat plasma was developed and successfully applied on pharmacokinetic studies. The present study was carried out to determine the metabolic pathways of piracetam for phase I metabolism and used cytochrome P450 isoforms responsible for the piracetam metabolism in human liver microsomes (HLMs). While additional potential metabolites of piracetam were suggested by computer-modeling. The resulting 2-(2-oxopyrrolidin-1-yl) acetic acid was the sole metabolite detected after the microsomal treatment. The amide hydrolysis mainly underwent to form a metabolite i.e., 2-(2-oxopyrrolidin-1-yl) acetic acid (M1). Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Effects of 1,2-dibromo-3-chloropropane on hepatic heme synthesis

International Nuclear Information System (INIS)

Moody, D.E.; Clawson, G.A.; Piper, W.N.; Smuckler, E.A.

1984-01-01

Previous studies showed that 1,2-dibromo-3-chloropropane (DBCP) caused a decrease in hepatic microsomal cytochrome P-450 suggesting that hepatic heme metabolism may be affected by DBCP treatment. Various parameters of hepatic heme synthesis were measured at intervals ranging from 0 to 72 hr in male Sprague-Dawley rats given a single oral dose (200 mg/kg) of DBCP. Incorporation of the radiolabeled heme precursor [delta-14C]aminolevulinic acid (14C-ALA) into liver, protein, extracted heme, and subcellular fractions of liver homogenates was significantly decreased to 75, 58, and 81% of controls, respectively, at 24 hr. At 48 and 72 hr after DBCP treatment, the accumulation of 14C-ALA label after 4 hr in liver homogenates and subcellular fractions was significantly increased in comparison to controls. These changes in 14C-ALA uptake were accompanied by decreases in total liver and microsomal heme, but not mitochondrial heme. Decreases were found in the spectral content of two heme proteins, cytochromes P-450 and b5, and the activity of another heme protein, catalase. Heme oxygenase activity increased to 130, 151, 209, and 186% of control values at 12, 24, 48, and 72 hr after DBCP, respectively. A slight, but significant, increase in ALA-synthetase to 112% of controls occurred at 24 hr, and slight, but significant, decreases in ALA-dehydratase to 90 and 80% of control occurred at 12 and 24 hr, respectively. No significant changes in uroporphyrinogen-1-synthetase or ferrochelatase at the time points tested was noted. The porphyrin content of liver was increased to 130% of control, while the serum and urine porphyrin levels were decreased to 30% of the control values at 24 hr. Liver ALA content was not significantly altered through the time period studied, but serum and urine levels were increased at 24 hr to 176 and 130% of the control values, respectively. In conclusion, the decreases in liver heme proteins following a single oral dose of DBCP are accompanied by

Pathological mechanisms of alcohol-induced hepatic portal hypertension in early stage fibrosis rat model.

Science.gov (United States)

Li, Jian; Niu, Jian-Zhao; Wang, Ji-Feng; Li, Yu; Tao, Xiao-Hua

2005-11-07

To study the role of hepatic sinusoidal capillarization and perisinusoidal fibrosis in rats with alcohol-induced portal hypertension and to discuss the pathological mechanisms of alcohol-induced hepatic portal hypertension. Fifty SD rats were divided into control group (n=20) and model group (n=30). Alcoholic liver fibrosis rat model was induced by intragastric infusion of a mixture containing alcohol, corn oil and pyrazole (1 000:250:3). Fifteen rats in each group were killed at wk 16. The diameter and pressure of portal vein were measured. Plasma hyaluronic acid (HA), type IV collagen (CoIV) and laminin (LN) were determined by radioimmunoassay. Liver tissue was fixed in formalin (10%) and 6-mum thick sections were routinely stained with Mallory and Sirius Red. Liver tissue was treated with rabbit polyclonal antibody against LN and ColIV. Hepatic non-parenchymal cells were isolated, total protein was extracted and separated by SDS-PAGE. MMP-2 and TIMP-1 protein expression was estimated by Western blotting. The diameter (2.207+/-0.096 vs 1.528+/-0.054 mm, Pportal vein were significantly higher in model group than those in the control group. Plasma HA (129.97+/-16.10 vs 73.09+/-2.38 ng/mL, Pmodel group. Abundant collagen deposited around the central vein of lobules, hepatic sinusoids and hepatocytes in model group. ColI and ColIII increased remarkably and perisinusoids were almost surrounded by ColIII. Immunohistochemical staining showed that ColIV protein level (0.130+/-0.007 vs 0.032+/-0.004, Pprotein level (0.152+/-0.005 vs 0.029+/-0.005, Pmodel group. MMP-2 protein expression (2.306+/-1.089 vs 0.612+/-0.081, Pprotein expression (3.015+/-1.364 vs 0.446+/-0.009, Pmodel group and TIMP-1 protein expression was evidently higher than MMP-2 protein expression (2.669+/-0.170 vs 1.695+/-0.008, Pportal hypertension in rats.

Fibrogenic response of hepatic stellate cells in ovariectomised rats exposed to ketogenic diet.

Science.gov (United States)

Bobowiec, R; Wojcik, M; Jaworska-Adamu, J; Tusinska, E

2013-02-01

The discrepancy about the role of estrogens in hepatic fibrogenesis and lack of studies addressed of ketogenic diet (KD) on hepatic stellate cells (HSC), prompted us to investigate the activity of HSC in control, KD- and thioacetamide (TAA)-administrated rats with different plasma concentration of estradiol (E2). HSC were isolated by the collagenase perfusion methods and separated by the Percoll gradient centrifugation. After the 4(th) and 8(th) day of incubation, lysates of HSC and the media were collected for further analysis. The HSC derived from KD-rats released remarkably more transforming growth factor (TGF)-β1 than cells obtained from animals fed with a standard diet. The ovariectomy of KD-rats markedly intensified the secretion of this fibrogenic cytokine on the 8(th) day of incubation (201.33 ±1 7.15 pg/ml). In HSC of rats exposed to E2, the TGF-β1 concentration did not exceed 157 ± 34.39 pg/ml. In respect to the collagen type I, the HSC obtained from ovariectomised KD-rats released an augmented amount of this ECM protein after the 8(th) day of culture (1.83 ± 0.14 U/ml). In the same time, higher quantities of ASMA appeared in the KD rats (1.41 ± 0.3 pg/mg protein). Exposition of rats to E2 did not markedly decrease the amount of ASMA. In summary, KD was able to induce morphological and functional changes in HSC, especially derived from rats deprived of ovarian estrogens. However, the preservation of E2 in ovariectomised rats didn't substantially alter the activation of HSC.

Effects of chronic ethanol administration on hepatic glycoprotein secretion in the rat

International Nuclear Information System (INIS)

Sorrell, M.F.; Nauss, J.M.; Donohue, T.M. Jr.; Tuma, D.J.

1983-01-01

The effects of chronic ethanol feeding on protein and glycoprotein synthesis and secretion were studied in rat liver slices. Liver slices from rats fed ethanol for 4-5 wk showed a decreased ability to incorporate [ 14 C]glucosamine into medium trichloracetic acid-precipitable proteins when compared to the pair-fed controls; however, the labeling of hepatocellular glycoproteins was unaffected by chronic ethanol treatment. Immunoprecipitation of radiolabeled secretory (serum) glycoproteins with antiserum against rat serum proteins showed a similar marked inhibition in the appearance of glucosamine-labeled proteins in the medium of slices from ethanol-fed rats. Minimal effects, however, were noted in the labeling of intracellular secretory glycoproteins. Protein synthesis, as determined by measuring [ 14 C]leucine incorporation into medium and liver proteins, was decreased in liver slices from ethanol-fed rats as compared to the pair-fed controls. This was the case for both total proteins as well as immunoprecipitable secretory proteins, although the labeling of secretory proteins retained in the liver slices was reduced to a lesser extent than total radiolabeled hepatic proteins. When the terminal sugar, [ 14 C]fucose, was employed as a precursor in order to more closely focus on the final steps of hepatic glycoprotein secretion, liver slices obtained from chronic ethanol-fed rats exhibited impaired secretion of fucose-labeled proteins into the medium. When ethanol (5 or 10 mM) was added to the incubation medium containing liver slices from the ethanol-fed rats, the alterations in protein and glycoprotein synthesis and secretion caused by the chronic ethanol treatment were further potentiated. The results of this study indicate that liver slices prepared from chronic ethanol-fed rats exhibit both impaired synthesis and secretion of proteins and glycoproteins, and these defects are further potentiated by acute ethanol administration

A simple assay method for omega-oxidation of lauric acid by hepatic enzymes

International Nuclear Information System (INIS)

Giera, D.D.; van Lier, R.B.L.

1990-01-01

Routine assessment of hepatic ω-oxidation of fatty acids in toxicology studies requires a simpler method of enzymatic analysis than HPLC or TLC. A method depending upon selective solvent separation of 14 C-lauric acid and 14 C-11/12-hydroxy lauric acid was developed. Following enzymatic incubation and addition of 15% methanol to the acidified incubation mixtures, partitioning with an alkane solvent such as iso-octane, cyclohexane, or n-hexane separated the lauric acid substrate and ω-hydroxylated products into two immiscible phases. Approximately 98% of the substrate partitioned into the organic phase, and approximately 83% of the hydroxylated products partitioned into the aqueous phase. Subsequent quantitation of the enzymatic activity required only liquid scintillation counting of the aqueous phase. Hepatic homogenates from male rats treated with 0.01, 0.05, 0.125, and 0.25% clofibrate in the diet for 7 days had enzyme levels 1.3, 6.1, 11.1, and 15.9 times control values, respectively, when assayed by conventional TLC methods, and 1.3, 5.3, 12.3, and 15.3 times control values when assayed by the solvent extraction method. The data indicate that the selective solvent partitioning yields comparable precision and sensitivity to the more conventional TLC method when studying induction of hepatic microsomal enzymes

Characterization of murine hepatitis virus (JHM) RNA from rats with experimental encephalomyelitis.

Science.gov (United States)

Jackson, D P; Percy, D H; Morris, V L

1984-09-01

When Wistar Furth rats are inoculated intracerebrally with the murine hepatitis virus JHM they often develop a demyelinating disease with resulting hind leg paralysis. Using an RNA transfer procedure and hybridization kinetic analysis, the virus-specific RNA in these rats was characterized. The pattern of JHM-specific RNA varied with individual infections of Wistar Furth rats. However, two species of JHM-specific RNA, the nucleocapsid and a 2.1-2.4 X 10(6)-Da RNA species were generally present. A general decrease in JHM-specific RNA in brains and spinal cord samples taken later than 20 days postinoculation was observed; however, JHM-specific RNA persisted in the spinal cord longer than in the brain of these rats.

Antithyroid microsomal antibody

Science.gov (United States)

Thyroid antimicrosomal antibody; Antimicrosomal antibody; Microsomal antibody; Thyroid peroxidase antibody; TPOAb ... Granulomatous thyroiditis Hashimoto thyroiditis High levels of these antibodies have also been linked with an increased risk ...

Identification of cytochrome P450s involved in the metabolism of 6-benzyl-1-benzyloxymethyl-5-iodouracil (W-1) using human recombinant enzymes and rat liver microsomes in vitro.

Science.gov (United States)

Lu, Ying-Yuan; Cheng, Hai-Xu; Wang, Xin; Wang, Xiao-Wei; Liu, Jun-Yi; Li, Pu; Lou, Ya-Qing; Li, Jun; Lu, Chuang; Zhang, Guo-Liang

2017-08-01

1. The aim of this study was to identify the hepatic metabolic enzymes, which involved in the biotransformation of 6-benzyl-1-benzyloxymethyl-5-iodouracil (W-1), a novel non-nucleoside reverse transcriptase inhibitor (NNRTI) in rat and human in vitro. 2. The parent drug of W-1 was incubated with rat liver microsomes (RLMs) or recombinant CYPs (CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1, CYP3A4, and CYP3A5, respectively) in the presence or absence of nicotinamide adeninedinucleotide phosphate (NADPH)-regenerating system. The metabolites of W-1 were analyzed with liquid chromatography-ion trap-time of flight-mass spectrometry (LC-IT-TOF-MS). 3. The parent drug of W-1 was metabolized in a NADPH-dependent manner in RLMs. The kinetic parameters of prototype W-1 including K m , V max , and CL int were 2.3 μM, 3.3 nmol/min/mg protein, and 1.4 mL/min/mg protein, respectively. Two metabolites M1 and M2 were observed in shorter retention times (2.988 and 3.188 min) with a higher molecular ion at m/z 463.0160 (both M1 and M2) than that of the W-1 parent drug (6.158 min with m/z 447.0218). The CYP selective inhibition and recombinant enzymes also showed that two hydroxyl metabolites M1 and M2 are mainly mediated by CYP2C19 and CYP3A4. 4. The identification of CYPs involved in W-1 biotransformation is important to understand and minimize, if possible, the potential of drug-drug interactions.

Visceral organ mass and hepatic protein synthetic capacity in fed and fasted rats

International Nuclear Information System (INIS)

Burrin, D.G.; Britton, R.A.; Ferrell, C.L.

1986-01-01

Forty-two male rats (avg wt. = 320 g) were used to assess the effect of severe nutrient restriction (72 h fast) on visceral organ mass and hepatic protein synthetic capacity as measured by in vitro incorporation of U- 14 -C-VALINE ( 14 C-VAL) into isolated hepatocytes. Organ weights expressed as a percent of empty body weight for fed vs. fasted rats were; liver (5.21 +/- .54 vs 3.82 +/- .46), kidney (.87 +/- 0.6 vs .89 +/- .05), stomach (.60 +/- .06 vs .61 +/- .06), intestines (3.70 +/- .44 vs 3.41 +/- .37). No differences were observed in in vitro oxygen consumption (15.7 +/- 3.1 vs 16.1 +/- 3.3, umole min -1 g -1 dry tissue) or 14 -C VAL incorporation (4.93 +/- 1.28 vs 4.31 +/- 1.48, dpm min -1 mg -1 dry tissue) for hepatocytes from fed vs. fasted rats. Analysis of perfused liver tissue indicated fed rats had higher protein (152.1 +/- 16.3 vs 136.6 +/- 29.6, mg/g tissue) and RNA (8.81 +/- 1.66 vs 5.97 +/- 1.87, mg/g tissue) with lower DNA (2.19 +/- .31 vs 3.19 +/- .54, mg/g tissue) compared to fasted rats. Protein-nucleic acid ratios suggest liver tissue from fed rats had a greater capacity for protein synthesis compared to fasted rats, however, this was not evident from in vitro hepatocyte 14 -C VAL incorporation estimates. These data indicate that severe nutrient restriction (72 h fast) affects visceral organ mass largely by reduced liver and gut size as well as decreased hepatic protein synthetic capacity

Gastric emptying in rats with acetaminophen-induced hepatitis

Directory of Open Access Journals (Sweden)

G. Hessel

1998-09-01

Full Text Available The objective of this work was to study the gastric emptying (GE of liquids in fasted and sucrose-fed rats with toxic hepatitis induced by acetaminophen. The GE of three test meals (saline, glucose and mayonnaise was evaluated in Wistar rats. For each meal, the animals were divided into two groups (N = 24 each. Group I was fed a sucrose diet throughout the experiment (66 h while group II was fasted. Forty-two hours after the start of the experiment, each group was divided into two subgroups (N = 12 each. Subgroup A received a placebo and subgroup B was given acetaminophen (1 g/kg. Twenty-four hours later, the GE of the three test meals was assessed and blood samples were collected to measure the serum levels of alanine aminotransferase (ALT, aspartate aminotransferase (AST and acetaminophen. In group IB, the mean AST and ALT values were 515 and 263 IU/l, respectively, while for group IIB they were 4014 and 2472 IU/l, respectively. The mean serum acetaminophen levels were higher in group IIB (120 µg/ml than in group IB (87 µg/ml. The gastric retention values were significantly higher in group IIB than in group IIA for all three test meals: saline, 51 vs 35%; glucose, 52 vs 38% and mayonnaise, 51 vs 29% (median values. The correlation between gastric retention and AST levels was significant (P<0.05 for group IIB for the three test meals: r = 0.73, 0.67 and 0.68 for saline, glucose and mayonnaise, respectively. We conclude that GE is altered in rats with hepatic lesions induced by acetaminophen, and that these alterations may be related to the liver cell necrosis caused by the drug.

Features of Hepatitis in Hepatitis-associated Aplastic Anemia: Clinical and Histopathologic Study.

Science.gov (United States)

Patel, Kalyani R; Bertuch, Alison; Sasa, Ghadir S; Himes, Ryan W; Wu, Hao

2017-01-01

Hepatitis-associated aplastic anemia (HAA) is a rare variant of aplastic anemia in which patients present with severe pancytopenia after an episode of acute hepatitis. The marrow failure is often rapid, severe, and usually fatal if untreated. The preceding hepatitis is largely under-studied. Retrospective study of the clinical and histopathologic features of hepatitis in pediatric patients who subsequently developed aplastic anemia and comparison with consecutive cases of acute liver failure and random cases of autoimmune hepatitis during the same time frame. All 7 patients of HAA had significant elevations in aminotransferases and conjugated hyperbilirubinemia at initial presentation. Echoing liver function indices, cholestatic hepatitis with sinusoidal obstruction-type endothelial injury was seen histomorphologically. Autoimmune hepatitis serology such as anti-F-actin, anti-liver/kidney microsome, and hypergammaglobulinemia was negative in all patients. Five of 7 patients (71.4%) had, however, elevated antinuclear antibody, all with a speckled pattern. Hepatitis virus serology was negative in all patients. By immunohistochemical staining, the lobular CD8/CD4 lymphocyte ratio was markedly elevated in all of the initial samples with significant reduction in this ratio (P = 0.03) in 3 patients post treatment (ursodiol, antibiotics, and/or immunosuppressive therapy). Hepatitis preceding HAA is characterized by marked elevation of aminotransferases, conjugated hyperbilirubinemia, elevated antinuclear antibody with a speckled pattern, cholestatic hepatitis with sinusoidal obstruction morphology, and CD8 dominant lobular infiltrates. The present study suggests HAA may result from cytotoxic T-cell-mediated sinusoidal endothelial and hepatocytic injury.

Long-Time Choledochal Clamping in Wistar Rats Causes Biliary Obstruction Progressing to Hepatic Fibrosis.

Science.gov (United States)

Jorge, G D L; Tártaro, R R; Escanhoela, C A F; Boin, I D F S F

2016-09-01

Biliary complications are important causes of morbidity and mortality in patients undergoing hepatic surgery. The aim of the study was to evaluate late liver alterations after a long period of choledochal clamping in Wistar rats. Ten male Wistar rats, weighing 304 grams, anesthetized with sodium thiopental (25 mg/kg) and xylazine (10 mg/kg) intravenously, were distributed into 2 groups: the choledochal clamping group (CCG) and the operation sham group (OSG), with 5 animals each submitted to an abdominal incision. In the CCG, the choledochal was isolated, dissected, and clamped with a microvascular clamp for 40 minutes. After this occlusion time, the clamp was removed and the incision was closed. In the OSG the animals, under normal conditions, were submitted only to anesthesia and laparotomy for choledochal manipulation. In all animals, after the 31st day, a hepatic biopsy was carried out for histology and blood biochemical tests: total bilirubin, alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, and gamma-glutamyl transferase. The animals were euthanized under anesthesia. This research was approved by the Ethics Committee on Animal Use (CEUA, Unicamp, No. 2511-1). In the CCG, 100% of the animals showed bile duct dilatation, ductular proliferation, and portal inflammatory infiltrate; 60% showed regenerative nodule formation; and 80% had porta-porta septa and foci of necrosis, all of which were not found in the OSG. All CCG group biochemical tests had significant increases (P Wistar rats caused hepatic dysfunction and biochemical and histological injuries with degrees of distortion to the hepatic architecture. Copyright © 2016 Elsevier Inc. All rights reserved.

Isoflavonoid-based bone-sparing treatments exert a low activity on reproductive organs and on hepatic metabolism of estradiol in ovariectomized rats

International Nuclear Information System (INIS)

Phrakonkham, Pascal; Chevalier, Joelle; Desmetz, Catherine; Pinnert, Marie-France; Berges, Raymond; Jover, Emmanuel; Davicco, Marie-Jeanne; Bennetau-Pelissero, Catherine; Coxam, Veronique; Artur, Yves; Canivenc-Lavier, Marie-Chantal

2007-01-01

The use of soy isoflavones is a potential alternative to hormone replacement therapy in post-menopausal bone-loss prevention. Nevertheless, phytoestrogens can target other organs and may disrupt cell proliferation, or could modify endogenous steroid hormone metabolism. These mechanisms could be linked to an increased risk of developing cancer. We therefore studied the possible side effects of such treatments in an experimental model of menopause. Forty adult female Wistar rats were ovariectomized and fed with a genistein-, daidzein- or equol-supplemented diet at bone-sparing levels (10 mg/kg BW/day) for 3 months. The estrogenic effects were assessed by histological and molecular analyses on reproductive organs. The impact on the oxidative metabolism of estradiol and on associated cytochrome P450 (CYP) activities was evaluated in liver microsomes. The relative wet weights of both the uterus and the vagina were increased in the equol group, but no significant changes in proliferating cell nuclear antigen or hormone receptor mRNA expression were noticed. In contrast, genistein and daidzein did not induce uterotrophy but caused an overexpression of estrogen receptor α mRNA which could correspond to a long-lasting effect of physiological concentrations of estrogens. The hepatic metabolism of estradiol was influenced by daidzein which increased the synthesis of putative mutagenic derivatives. At the same time, genistein favored estrogen 2-hydroxylation, and equol decreased 4-hydroxyestrogen production. Surprisingly, no significant alteration in hepatic CYP activities was detected. Taken together, these results demonstrate that isoflavonoid-based bone-sparing treatments are able to cause side effects on other estrogen-sensitive target organs when given in the long-term

Taurine ameliorates cholesterol metabolism by stimulating bile acid production in high-cholesterol-fed rats.

Science.gov (United States)

Murakami, Shigeru; Fujita, Michiko; Nakamura, Masakazu; Sakono, Masanobu; Nishizono, Shoko; Sato, Masao; Imaizumi, Katsumi; Mori, Mari; Fukuda, Nobuhiro

2016-03-01

This study was designed to investigate the effects of dietary taurine on cholesterol metabolism in high-cholesterol-fed rats. Male Sprague-Dawley rats were randomly divided into two dietary groups (n = 6 in each group): a high-cholesterol diet containing 0.5% cholesterol and 0.15% sodium cholate, and a high-cholesterol diet with 5% (w/w) taurine. The experimental diets were given for 2 weeks. Taurine supplementation reduced the serum and hepatic cholesterol levels by 37% and 32%, respectively. Faecal excretion of bile acids was significantly increased in taurine-treated rats, compared with untreated rats. Biliary bile acid concentrations were also increased by taurine. Taurine supplementation increased taurine-conjugated bile acids by 61% and decreased glycine-conjugated bile acids by 53%, resulting in a significant decrease in the glycine/taurine (G/T) ratio. Among the taurine-conjugated bile acids, cholic acid and deoxycholic acid were significantly increased. In the liver, taurine supplementation increased the mRNA expression and enzymatic activity of hepatic cholesterol 7α-hydroxylase (CYP7A1), the rate-limiting enzyme for bile acid synthesis, by three- and two-fold, respectively. Taurine also decreased the enzymatic activity of acyl-CoA:cholesterol acyltransferase (ACAT) and microsomal triglyceride transfer protein (MTP). These observations suggest that taurine supplementation increases the synthesis and excretion of taurine-conjugated bile acids and stimulates the catabolism of cholesterol to bile acid by elevating the expression and activity of CYP7A1. This may reduce cholesterol esterification and lipoprotein assembly for very low density lipoprotein (VLDL) secretion, leading to reductions in the serum and hepatic cholesterol levels. © 2016 John Wiley & Sons Australia, Ltd.

Toxicology and metabolism of nickel compounds. Progress report, December 1, 1978-November 30, 1979. [Hamsters and rats

Energy Technology Data Exchange (ETDEWEB)

Sunderman, F.W. Jr.

1979-08-15

The toxicology and metabolism of nickel compounds were investigated in rats and hamsters. The new knowledge includes; demonstration that nickel carbonyl is teratogenic for hamsters; elucidation of physiological factors which influence ..cap alpha..Ni/sub 3/S/sub 2/-induced erythrocytosis in rats; development of a sensitive assay for heme oxygenase activity in renal microsomes for use in studies of renal effects of nickel compounds; demonstration that administration of Ni(CO)/sub 4/ to rats inhibits incorporation of /sup 3/H-thymidine into DNA during hepatic regeneration; demonstration that clones of Syrian hamster fetal cells which have been transformed by in vitro exposure to ..cap alpha..Ni/sub 3/S/sub 2/ consistently cause sarcomas following sc injection into nude mice; demonstration that nickel carbonyl-cyclopentadiene dimer induces rhabdomyosarcomas following im injection in rats; observation of differences in carcinogenic activities of several insoluble nickel compounds; discovery that intraocular injection of ..cap alpha..Ni/sub 3/S/sub 2/ induces amelanotic melanomas in rats; and refinement of analytical methods for nickel in biological materials.

Etiology of fatty liver in dairy cattle: effects of nutritional and hormonal status on hepatic microsomal triglyceride transfer protein.

Science.gov (United States)

Bremmer, D R; Trower, S L; Bertics, S J; Besong, S A; Bernabucci, U; Grummer, R R

2000-10-01

We conducted three experiments to determine the effects of nutritional and hormonal status on microsomal triglyceride transfer protein (MTP) activity and mass. In experiment 1, 18 nonlactating Holstein cows, 75 d before expected calving date, in their second gestation or greater were monitored from d 75 to 55 prepartum. Cows were fed a control diet from d 75 to 62 prepartum for covariable measurements. From d 61 to 55 prepartum, six cows continued to receive the control diet, six cows were restricted to 2.3 kg of grass hay/d, and six cows were fed the control diet plus 1.8 kg of concentrate/d and 500 ml of propylene glycol given 2 times/d as an oral drench. Plasma glucose and serum insulin concentrations were highest in cows that received propylene glycol and lowest in feed restricted cows. Plasma nonesterified fatty acids (NEFA) and liver triglyceride (TG) concentrations were highest in feed restricted cows and not different between cows that received the control diet and cows that received propylene glycol. Hepatic MTP activity and mass were not affected by treatment in experiment 1. In experiment 2, bovine hepatocytes isolated from the caudate process of five preruminating Holstein bull calves were incubated with either 0, 0.5, 1.0, or 2.0 mM NEFA for 48 h. Intracellular TG increased linearly as NEFA concentration in the media increased. Concentration of NEFA in the incubation media had no effect on MTP activity or mass. There was a quadratic effect of concentration of NEFA in the incubation media on MTP mRNA. In experiment 3, bovine hepatocytes isolated from the caudate process of five preruminating Holstein bull calves were incubated with 2 mM [1-14C]oleate for 24 h to accumulate TG, followed by a 36-h period of TG depletion, during which hepatocytes were incubated with no hormone, 10 nM insulin, or 10 nM glucagon. There was no effect of insulin or glucagon on intracellular TG, MTP activity or mass. Cells incubated with no hormone had higher levels of MTP m

The effects of benzodiazepine-receptor antagonists and partial inverse agonists on acute hepatic encephalopathy in the rat

NARCIS (Netherlands)

Bosman, D. K.; van den Buijs, C. A.; de Haan, J. G.; Maas, M. A.; Chamuleau, R. A.

1991-01-01

Two benzodiazepine-receptor partial inverse agonists (Ro 15-4513, Ro 15-3505) and one benzodiazepine-receptor antagonist (flumazenil) were administered to rats with hepatic encephalopathy due to acute liver ischemia. Significant improvement (P less than 0.002) of both the clinical grade of hepatic

Protective Effect of Ethyl Acetate Fraction of Stereospermum Suaveolens Against Hepatic Oxidative Stress in STZ Diabetic Rats.

Science.gov (United States)

Balasubramanian, Thirumalaiswamy; Senthilkumar, G P; Karthikeyan, M; Chatterjee, Tapan Kumar

2013-07-01

Stereospermum suaveolens is a folk remedy for the treatment of diabetes and liver disorders in southern parts of India. In the present study, the protective effect of the ethyl acetate fraction of ethanol extract from S. suaveolens against hepatic oxidative stress was evaluated in streptozotocin (STZ)-induced diabetic rats for 14 days. The ethyl acetate fraction was administered orally to the STZ diabetic rats at the doses of 200 and 400 mg/kg. Blood glucose level was measured according to glucose oxidase method. In order to determine hepatoprotective activity, changes in the levels of serum biomarker enzymes such as aspartate transaminase (AST), alanine transaminase (ALT), and serum alkaline phosphatase (SALP) were assessed in the ethyl acetate fraction treated diabetic rats and were compared with the levels in diabetic control rats. In addition, the antioxidant activity of ethyl acetate fraction was evaluated using various hepatic parameters such as thiobarbituric acid reactive substances (TBARS), reduced glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT). It was found that administration of ethyl acetate fraction (200 and 400 mg/kg) produced a significant (P SALP, while elevating the GSH levels, and SOD and CAT activities in diabetic rats. Histopathologic studies also revealed the protective effect of ethyl acetate fraction on the liver tissues of diabetic rats. It was concluded from this study that the ethyl acetate fraction from ethanol extract of S. suaveolens modulates the activity of enzymatic and nonenzymatic antioxidants and enhances the defense against hepatic oxidative stress in STZ-induced diabetic rats.

Kombucha Tea Ameliorates Trichloroethylene Induced Hepatic Damages in Rats via Inhibition of Oxidative Stress and Free Radicals Induction

International Nuclear Information System (INIS)

Gharib, O.A.; Gharib, M.A.

2008-01-01

Kombucha Tea (KT) is reported to exhibit a wide variety of biological effects, including antioxidant. Evidence shows the important role of oxidative stress in the hepatic damage. The aim of this study is to investigate the possible protective effects of oral administration of KT in rats with trichloroethylene (TCE)-induced damage for ten consecutive days. Hepatic damage was evaluated by measuring total free radicals levels, biochemical and histological examinations. Serum gamma glutamyl transferase (GGT) activity (the hepatic damage marker), total protein, albumin and globulin as well as malonaldehyde (MDA), glutathione (GSH) content, nitric oxide (NO) concentration were evaluated in liver tissue homogenates. Total free radicals concentration in blood was examined by electron spin resonance (ESR). Total protein, DNA concentration, cell number and cell size in liver tissues were also examined. The rats orally administrated with TCE for ten days indicates hepatic damage changes, an increase in blood total free radicals concentration was observed, serum GGT activity, liver MDA, NO levels, total protein and decreased GSH content, DNA concentration and cell number. This accompanied with an increase in cell size of liver tissues, whereas KT reversed these effects. Furthermore, KT inhibits the concentration of total free radicals in blood and decreasing the increment of MDA and NO concentration. Histological studies reveal partial healing in those rats treated by KT after oral administration with TCE. The present results suggest that KT ameliorates TCE induced hepatic damage in rats probably due to its content of glucuronic, acetic acid and B vitamins via inhibition of oxidative stress and total free radicals

Study on pretreatment of FPS-1 in rats with hepatic ischemia-reperfusion injury.

Science.gov (United States)

Lin, Shiqing; Liu, Kexuan; Wu, Weikang; Chen, Chao; Wang, Zhi; Zhang, Xuanhong

2009-01-01

This study was designed to determine whether FPS-1, the water-soluble polysaccharide isolated from fuzi, protected against hepatic damage in hepatic ischemia-reperfusion injury in rats, and its mechanism. SD rats were subjected to 60 min of hepatic ischemia, followed by 120 min reperfusion. FPS-1 (160 mg/kg/day) was administered orally for 5 days before ischemia-reperfusion injury in treatment group. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and albumin (ALB) were assayed to evaluate liver functions. Liver samples were taken for histological examination and determination of malondialdehyde (MDA), superoxide dismutase (SOD), that catalase (CAT) in liver. Na(+)-K(+)-ATPase and Ca(2+)-ATPase in mitochondria were measured with colorimetry method. Morphological changes were also investigated by using both light microscopy and electron microscopy (EM). In addition, apoptosis and oncosis were detected by Annexin V-FITC/PI immunofluorescent flow cytometry analysis. Serum AST and ALT levels were elevated in groups exposed to ischemia-reperfusion (p FPS-1 reversed all these biochemical parameters as well as histological alterations, evidently by increased SOD, CAT, reduced MDA and histological scores compared to the model group (p FPS-1 could attenuate the necrotic states by the detection of immunofluorescent flow cytometry analysis. Pretreatment with FPS-1 reduced hepatic ischemia-reperfusion injury through its potent antioxidative effects and attenuation of necrotic states.

Sex-related differences in the enhancing effects of perfluoro-octanoic acid on stearoyl-CoA desaturase and its influence on the acyl composition of phospholipid in rat liver. Comparison with clofibric acid and tiadenol.

Science.gov (United States)

Kawashima, Y; Uy-Yu, N; Kozuka, H

1989-01-01

The effects of the peroxisome proliferators clofibric acid (p-chlorophenoxyisobutyric acid), tiadenol [2,2'-(decamethylenedithio)diethanol] and perfluoro-octanoic acid (PFOA) on hepatic stearoyl-CoA desaturation in male and female rats were compared. Treatment of male rats with the three peroxisome proliferators increased markedly the activity of stearoyl-CoA desaturase. Administration of clofibric acid or tiadenol to female rats increased greatly the hepatic activity of stearoyl-CoA desaturase, the extent of the increases being slightly less pronounced than those of male rats. In contrast with the other two peroxisome proliferators, however, PFOA did not change the activity of stearoyl-CoA desaturase in female rats. Hormonal manipulations revealed that this sex-related difference in the effect of PFOA on stearoyl-CoA desaturase activity is strongly dependent on testosterone. The increase in stearoyl-CoA desaturase activity by peroxisome proliferators was not accompanied by any notable increases in the microsomal content of cytochrome b5 or the activity of NADH: cytochrome b5 reductase. The administration of the peroxisome proliferators greatly altered the acyl composition of hepatic phosphatidylcholine and phosphatidylethanolamine (namely the proportions of C18:1 and C20:3,n-9 fatty acids increased in both phospholipids), and the alterations were partially associated with the increase in stearoyl-CoA desaturase activity. PMID:2574572

Autoimmunity and Extrahepatic Manifestations in Treatment-Naïve Children with Chronic Hepatitis C Virus Infection

Directory of Open Access Journals (Sweden)

Giuseppe Indolfi

2012-01-01

Full Text Available Hepatitis C virus (HCV infection has been associated with autoimmunity and extrahepatic manifestations in adults. Few data are available on these topics in children. Nonorgan specific auto-antibodies development is part of the natural course of chronic hepatitis C in children. Smooth muscle autoantibody is the most common autoantibody found, while liver-kidney microsomal type-1 antibody positivity is the most peculiar autoimmune feature of children with HCV infection. The clinical significance of non-organ specific autoantibodies in the course of paediatric chronic hepatitis C is still debated. Autoantibody positivity can be considered neutral for most patients, while it can be associated with negative connotations for others, especially those positive for liver-kidney microsomal type-1 autoantibody. Subclinical hypothyroidism but not autoimmune thyroiditis has been demonstrated in HCV infection in children, while only few cases of HCV-associated membranoproliferative glomerulonephritis have been described. Single reports are available in the literature reporting the anecdotal association between chronic hepatitis C and other extrahepatic manifestations such as myopathy and opsoclonus-myoclonus syndrome. Despite the low incidence of extrahepatic manifestations of chronic hepatitis C in children, overall, available data suggest a careful monitoring.

Induction of biotransformation enzymes by the carcinogenic air-pollutant 3-nitrobenzanthrone in liver, kidney and lung, after intra-tracheal instillation in rats.

Science.gov (United States)

Mizerovská, Jana; Dračínská, Helena; Frei, Eva; Schmeiser, Heinz H; Arlt, Volker M; Stiborová, Marie

2011-02-28

3-Nitrobenzanthrone (3-NBA), a carcinogenic air pollutant, was investigated for its ability to induce cytochrome P450 (CYP) 1A1/2 and NAD(P)H:quinone oxidoreductase (NQO1) in liver, kidney and lung of rats treated by intra-tracheal instillation. The organs used were from a previous study performed to determine the persistence of 3-NBA-derived DNA adducts in target and non-target tissues (Bieler et al., Carcinogenesis 28 (2007) 1117-1121, [22]). NQO1 is the enzyme reducing 3-NBA to N-hydroxy-3-aminobenzanthrone (N-OH-3-ABA) and CYP1A enzymes oxidize a human metabolite of 3-NBA, 3-aminobenzanthrone (3-ABA), to yield the same reactive intermediate. 3-NBA and 3-ABA are both activated to species forming DNA adducts by cytosols and/or microsomes isolated from rat lung, the target organ for 3-NBA carcinogenicity, and from liver and kidney. Each compound generated the same five DNA adducts detectable by (32)P-postlabelling. When hepatic cytosols from rats treated with 0.2 or 2mg/kg body weight of 3-NBA were incubated with 3-NBA, DNA adduct formation was 3.2- and 8.6-fold higher, respectively, than in incubations with cytosols from control animals. Likewise, cytosols isolated from lungs and kidneys of rats exposed to 3-NBA more efficiently activated 3-NBA than those of control rats. This increase corresponded to an increase in protein levels and enzymatic activities of NQO1. Incubations of hepatic, pulmonary or renal microsomes of 3-NBA-treated rats with 3-ABA led to an 9.6-fold increase in DNA-adduct formation relative to controls. The highest induction in DNA-adduct levels was found in lung. The stimulation of DNA-adduct formation correlated with expression of CYP1A1/2 induced by the intra-tracheal instillation of 3-NBA. The results demonstrate that 3-NBA induces NQO1 and CYP1A1/2 in livers, lungs and kidneys of rats after intra-tracheal instillation, thereby enhancing its own genotoxic and carcinogenic potential. Copyright © 2010 Elsevier B.V. All rights reserved.

Multiple viral/self immunological cross-reactivity in liver kidney microsomal antibody positive hepatitis C virus infected patients is associated with the possession of HLA B51.

Science.gov (United States)

Bogdanos, D-P; Lenzi, M; Okamoto, M; Rigopoulou, E I; Muratori, P; Ma, Y; Muratori, L; Tsantoulas, D; Mieli- Vergani, G; Bianchi, F B; Vergani, D

2004-01-01

Liver Kidney Microsomal autoantibody type 1(LKM1) directed to cytochrome P4502D6 (CYP2D6) characterises autoimmune hepatitis type-2 (AIH-2), but is also found in a proportion of chronic hepatitis C virus (HCV) infected patients, CYP2D6252-271 being a major B- cell autoepitope. Molecular mimicry and immunological cross-reactivity between CYP2D6252-271, HCV polyprotein and the infected cell protein 4 (ICP4) of herpes simplex virus type 1 (HSV-1) have been suggested as triggers for the induction of LKM1, but reactivity and cross-reactivity to the relevant sequences have not been investigated experimentally. CYP2D6252-271 and its viral homologues were constructed and tested by ELISA in the sera of 46 chronically infected HCV patients, 23 of whom were LKM1 positive. Reactivity to the E1 HCV and ICP4 HSV1 mimics was frequently found in HCV infected patients irrespectively of their LKM1 status; viral/self cross-reactivity (as indicated by inhibition studies), however, was present in the only 2 of the 23 LKM1 seropositive HCV patients, who possessed the HLA allotype B51. Our results indicate that in HCV infected patients virus/self cross-reactivity is dependent on a specific immunogenetic background, a finding awaiting confirmation by studies in larger series of patients.

Comparison of the in vitro and in vivo hepatic metabolism of the carcinogen 1-nitropyrene

International Nuclear Information System (INIS)

Howard, P.C.; Flammang, T.J.; Beland, F.A.

1985-01-01

[4,5,9,10(- 3 )H]1-nitropyrene was incubated with NADH- or NADPH-fortified rat liver microsomes under an argon atmosphere. Residual substrate and metabolites were extracted with ethyl acetate and analyzed by high pressure liquid chromatography. Both reduced and oxidized products were formed: namely, 1-aminopyrene, trans-4,5-dihydroxy-4,5-dihydro-1-nitropyrene, and 3-, 6- and 8-hydroxy-1-nitropyrene. When incubations were conducted with rat liver cytosol, only the reduced products 1-nitrosopyrene and 1-aminopyrene were detected. In parallel experiments, [4,5, 9,10- 3 H]1-nitropyrene was administered to rats by intravenous injection or gavage and the bile was collected. After 4 h, approximately one-third of the intravenously-administered compound appeared in the bile as O-glucuronides of 3-, 6- and 8-hydroxy-1-nitropyrene, the O-glucuronide of trans-4,5-dihydroxy-4,5-dihydro-1-nitropyrene, and unidentified glutathione conjugates. The same metabolites were found in rats treated with 1-nitropyrene by gavage; however, only 10% of the dose appeared in the bile within 12 h. These studies indicate that both nitroreduction and ring oxidation are involved in the hepatic metabolism of 1-nitropyrene. The importance of these pathways in the etiology of 1-nitropyrene tumorigenesis is discussed

Chemoprotective effect of omega-3 fatty acids on thioacetamide induced hepatic fibrosis in male rats

Directory of Open Access Journals (Sweden)

Atef M. Al-Attar

2017-05-01

Full Text Available The current study was designed to investigate the possible protective effect of omega-3 fatty acids from fish oil on hepatic fibrosis induced by thioacetamide (TAA in male rats. The experimental animals were divided into four groups. The first group was received saline solution and served as control. The second group was given 250 mg/kg body weight of TAA. The third group was treated with omega-3 fatty acids and TAA. The fourth group was given saline solution and supplemented with omega-3 fatty acids. Treatment of rats with TAA for three and six weeks resulted in a significant decrease in body weight gain, while the value of liver/body weight ratio was statistically increased. Furthermore, the levels of serum alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, gamma glutamyl transferase and total bilirubin were significantly increased. After three weeks of exposure to only TAA, liver sections showed an abnormal morphology characterized by noticeable fibrosis with the extracellular matrix collagen contents and damage of liver cells’ structure. Liver sections from rats treated with only TAA for six weeks revealed an obvious increase in extracellular matrix collagen content and bridging fibrosis. Treating TAA-intoxicated rats with omega-3 fatty acids significantly attenuated the severe physiological and histopathological changes. Finally, the present investigation suggests that omega-3 fatty acids could act against hepatic fibrosis induced by TAA due to its antioxidant properties, thus supporting its use in hepatic fibrosis therapy.

Ascorbic acid deficiency stimulates hepatic expression of inflammatory chemokine, cytokine-induced neutrophil chemoattractant-1, in scurvy-prone ODS rats.

Science.gov (United States)

Horio, Fumihiko; Kiyama, Keiichiro; Kobayashi, Misato; Kawai, Kaori; Tsuda, Takanori

2006-02-01

ODS rat has a hereditary defect in ascorbic acid biosynthesis and is a useful animal model for elucidating the physiological role of ascorbic acid. We previously demonstrated by using ODS rats that ascorbic acid deficiency changes the hepatic gene expression of acute phase proteins, as seen in acute inflammation. In this study, we investigated the effects of ascorbic acid deficiency on the production of inflammatory chemokine, cytokine-induced neutrophil chemoattractant-1 (CINC-1), in ODS rats. Male ODS rats (6 wk of age) were fed a basal diet containing ascorbic acid (300 mg/kg diet) or a diet without ascorbic acid for 14 d. Obvious symptoms of scurvy were not observed in the ascorbic acid-deficient rats. Ascorbic acid deficiency significantly elevated the serum concentration of CINC-1 on d 14. The liver and spleen CINC-1 concentrations in the ascorbic acid-deficient rats were significantly elevated to 600% and 180% of the respective values in the control rats. However, the lung concentration of CINC-1 was not affected by ascorbic acid deficiency. Ascorbic acid deficiency significantly elevated the hepatic mRNA level of CINC-1 (to 480% of the value in the control rats), but not the lung mRNA level. These results demonstrate that ascorbic acid deficiency elevates the serum, liver and spleen concentrations of CINC-1 as seen in acute inflammation, and suggest that ascorbic acid deficiency stimulate the hepatic CINC-1 gene expression.

L-Carnitine Ameliorates Immunological-induced Hepatitis in rats

International Nuclear Information System (INIS)

Abd-Allah, Adel R.A.

2006-01-01

Immunological mediated hepatitis can be initiated by bacterial product; Lipopolysaccharide (LPS). The later is increased during severe infection, bacterial overgrowth or translocation. LPS stimulates Kupffer cells. Activation of the kupffer cells contributes to the onset of liver injuries by producing and releasing cytotoxic agents, inflammatory cytokines and reactive oxygen species. In the present study, L-carnitine, a natural antioxidant and immunoprotective agent, is used to protect against LPS-induced hepatitis. Liver content of glutathione (GSH), malondialdehyde (MDA), nitric oxide (NO) and the DNA adduct 8-hydroxydeoxyguanosine (8-HDG) are estimated. Serum activity of liver enzymes ALT, AST, and Gamma-GT, in addition to IL2 level are also estimated. Moreover, liver histopathological changes are determined. Results revealed that LPS (5mg/kg once i.p) significantly increased 8-HDG, MDA, NO and depleted GSH in the liver of the treated rats. It also increased serum IL2 and activity of all the estimated liver enzyme markers indicating massive hepatic cellular damage as also shown as a necrotic damage in liver histological sections. LCR administered (500mg/kg) 3h before LPS protected against LPS-induced lethality by 100%. LCR also prevented the increase in liver content of 8-HDG, MDA and NO. It reduced the depleted GSH and prevented the necrotic damage in the liver tissue as shown by normalization of ALT, AST and Gamma-Gt as well as IL2 and a remarkable improvement in liver histology. These data suggest that LCr could be used as an adjuvant therapy in severely infected and specific patients to counteract LPS-induced liver hepatitis. (author)

Antibodies against human cytochrome P-450db1 in autoimmune hepatitis type II.

Science.gov (United States)

Zanger, U M; Hauri, H P; Loeper, J; Homberg, J C; Meyer, U A

1988-11-01

In a subgroup of children with chronic active hepatitis, circulating autoantibodies occur that bind to liver and kidney endoplasmic reticulum (anti-liver/kidney microsome antibody type I or anti-LKM1). Anti-LKM1 titers follow the severity of the disease and the presence of these antibodies serves as a diagnostic marker for this autoimmune hepatitis type II. We demonstrate that anti-LKM1 IgGs specifically inhibit the hydroxylation of bufuralol in human liver microsomes. Using two assay systems with different selectivity for the two cytochrome P-450 isozymes catalyzing bufuralol metabolism in human liver, we show that anti-LKM1 exclusively recognizes cytochrome P-450db1. Immunopurification of the LKM1 antigen from solubilized human liver microsomes resulted in an electrophoretically homogenous protein that had the same molecular mass (50 kDa) as purified P-450db1 and an identical N-terminal amino acid sequence. Recognition of both purified P-450db1 and the immunoisolated protein on western blots by several monoclonal antibodies confirmed the identity of the LKM1 antigen with cytochrome P-450db1. Cytochrome P-450db1 has been identified as the target of a common genetic polymorphism of drug oxidation. However, the relationship between the polymorphic cytochrome P-450db1 and the appearance of anti-LKM1 autoantibodies as well as their role in the pathogenesis of chronic active hepatitis remains speculative.

Effect of fumonisin B1 on rat hepatic P450 system

NARCIS (Netherlands)

Spotti, M.; Maas, R.F.M.; Nijs, C.M. de; Fink-Gremmels, J.

2000-01-01

The effects of the mycotoxin fumonisin B1 (FB1) on the hepatic cytochrome P450 system were investigated in male rats dosed daily by oral gavage with 3 mg FB1 per kg body weight for 9 consecutive days. FB1 treatment resulted in a reduced weight gain. At the same time, CYP2E activity was increased,

Soy compared with milk protein in a Western diet changes fecal microbiota and decreases hepatic steatosis in obese OLETF rats.

Science.gov (United States)

Panasevich, Matthew R; Schuster, Colin M; Phillips, Kathryn E; Meers, Grace M; Chintapalli, Sree V; Wankhade, Umesh D; Shankar, Kartik; Butteiger, Dustie N; Krul, Elaine S; Thyfault, John P; Rector, R Scott

2017-08-01

Soy protein is effective at preventing hepatic steatosis; however, the mechanisms are poorly understood. We tested the hypothesis that soy vs. dairy protein-based diet would alter microbiota and attenuate hepatic steatosis in hyperphagic Otsuka Long-Evans Tokushima fatty (OLETF) rats. Male OLETF rats were randomized to "Western" diets containing milk protein isolate (MPI), soy protein isolate (SPI) or 50:50 MPI/SPI (MS) (n=9-10/group; 21% kcal protein) for 16 weeks. SPI attenuated (Pcontent, and hepatic 16:1 n-7 and 18:1 n-7 PUFA concentrations) (Pbacterial 16S rRNA analysis revealed SPI-intake elicited increases (P<.05) in Lactobacillus and decreases (P<.05) in Blautia and Lachnospiraceae suggesting decreases in fecal secondary bile acids in SPI rats. SPI and MS exhibited greater (P<.05) hepatic Fxr, Fgfr4, Hnf4a, HmgCoA reductase and synthase mRNA expression compared with MPI. Overall, dietary SPI compared with MPI decreased hepatic steatosis and diacylglycerols, changed microbiota populations and altered bile acid signaling and cholesterol homeostasis in a rodent model of obesity. Copyright © 2017 Elsevier Inc. All rights reserved.

Properties of latent and thiol-activated rat hepatic 3-hydroxy-3-methylglutaryl-coenzyme A reductase and regulation of enzyme activity.

Science.gov (United States)

Dotan, I; Shechter, I

1983-10-15

The effect of the thiols glutathione (GSH), dithiothreitol (DTT), and dithioerythritol (DTE) on the conversion of an inactive, latent form (El) of rat liver 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoA reductase, EC 1.1.1.34) to a catalyticaly active form (Ea) is examined. Latent hepatic microsomal HMG-CoA reductase is activated to a similar degree of activation by DTT and DTE and to a lower extent by GSH. All three thiols affect both Km and Vmax values of the enzyme toward HMG-CoA and NADPH. Studies of the effect of DTT on the affinity binding of HMG-CoA reductase to agarose-hexane-HMG-CoA (AG-HMG-CoA) resin shows that thiols are necessary for the binding of the enzyme to the resin. Removal of DTT from AG-HMG-CoA-bound soluble Ea (active enzyme) does not cause dissociation of the enzyme from the resin at low salt concentrations. Substitution of DTT by NADPH does not promote binding of soluble El (latent enzyme) to AG-HMG-CoA. The enzymatic activity of Ea in the presence of DTT and GSH indicates that these thiols compete for the same binding site on the enzyme. Diethylene glycol disulfide (ESSE) and glutathione disulfide (GSSG) inhibit the activity of Ea. ESSE is more effective for the inhibition of Ea than GSSG, causing a higher degree of maximal inhibition and affecting the enzymatic activity at lower concentrations. A method is described for the rapid conversion of soluble purified Ea to El using gel-filtration chromatography on Bio-Gel P-4 columns. These combined results point to the importance of the thiol/disulfide ratio for the modulation of hepatic HMG-CoA reductase activity.

Effect of Green Tea Extract Encapsulated Into Chitosan Nanoparticles on Hepatic Fibrosis Collagen Fibers Assessed by Atomic Force Microscopy in Rat Hepatic Fibrosis Model.

Science.gov (United States)

Safer, Abdel-Majeed A; Hanafy, Nomany A; Bharali, Dhruba J; Cui, Huadong; Mousa, Shaker A

2015-09-01

The present study examined the effect of Green Tea Extract (GTE) encapsulated into Chitosan Nanoparticles (CS-NPs) on hepatic fibrosis in rat model as determined by atomic force microscopy (AFM). The bioactive compounds in GTE encapsulated into CS-NPs were determined using LC-MS/MS method. Additionally, the uptake of GTE-CS NPs in HepG2 cells showed enhanced uptake. In experimental fibrosis model, AFM was used as a high resolution microscopic tool to investigate collagen fibers as an indicator of hepatic fibrosis induced by treatment with CCl4. Paraffin sections of fibrotic liver tissues caused by CC4 treatment of rats and the effect of GTE-CS NPs treatment with or without CCl4 on hepatic fibrosis were examined. Liver tissues from the different groups of animals were de-waxed and processed as for normal H/E staining and Masson's trichrome staining to locate the proper area of ECM collagen in the CCl4 group versus collagen in liver tissues treated with the GTE-CS NPs with or without CCl4. Selected areas of paraffin sections were trimmed off and fixed flat on top of mica and inserted in the AFM stage. H/E staining, Masson's trichrome stained slides, and AFM images revealed that collagen fibers of 250 to 300 nm widths were abundant in the fibrotic liver samples while those of GTE-CS NPs were clear as in the control group. Data confirmed the hypothesis that GTE-CS NPs are effective in removing all the extracellular collagen caused by CCl4 in the hepatic fibrosis rat liver.

Morphologic and biochemical changes in male rat lung after surgical and pharmacological castration

Directory of Open Access Journals (Sweden)

M.S. Ojeda

2000-03-01

Full Text Available The morphology of the rat lung was studied by light microscopy in different situations: after surgical and pharmacological castration and after administration of testosterone to the castrated rat to determine if the androgen is required to maintain the normal morphology of the lung. We also determined the effect of flutamide on the phospholipid composition of both the surfactant and microsomes of the lung. Rats were separated into five groups: I - control non-castrated rats, II - castrated rats sacrificed 21 days after castration, III - castrated rats that received testosterone daily from day 2 to day 21 after castration, IV - castrated rats that received testosterone from day 15 to day 21 after castration, and V - control rats injected with flutamide for 7 days. The amount of different phospholipids in the surfactant and microsomes of the lung was measured in group I and V rats. At the light microscopy level, the surgical and pharmacological castration provoked alterations in the morphology of the lung, similar to that observed in human lung emphysema. The compositions of surfactant and microsomes of the lung were similar to those previously reported by us for the surgically castrated rats. These results indicate that androgens are necessary for the normal morphology as well as for some metabolic aspects of the lung.

Agmatine protects rat liver from nicotine-induced hepatic damage via antioxidative, antiapoptotic, and antifibrotic pathways.

Science.gov (United States)

El-Sherbeeny, Nagla A; Nader, Manar A; Attia, Ghalia M; Ateyya, Hayam

2016-12-01

Tobacco smoking with its various forms is a global problem with proved hazardous effects to human health. The present work was planned to study the defending role of agmatine (AGM) on hepatic oxidative stress and damage induced by nicotine in rats. Thirty-two rats divided into four groups were employed: control group, nicotine-only group, AGM group, and AGM-nicotine group. Measurements of serum hepatic biochemical markers, lipid profile, and vascular cell adhesion molecule-1 were done. In addition, malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH) activity, and nitrate/nitrite (NOx) levels were estimated in the liver homogenates. Immunohistochemistry for Bax and transforming growth factor beta (TGF-β1) and histopathology of the liver were also included. Data of the study demonstrated that nicotine administration exhibited marked liver deterioration, an increase in liver enzymes, changes in lipid profile, and an elevation in MDA with a decline in levels of SOD, GSH, and NOx (nitrate/nitrite). Also, levels of proapoptotic Bax and profibrotic TGF-β1 showed marked elevation in the liver. AGM treatment to rats in nicotine-only group ameliorated all the previous changes. These findings indicate that AGM could successfully overcome the nicotine-evoked hepatic oxidative stress and tissue injury, apoptosis, and fibrosis.

Posttranslational modification of hepatic cytochrome P-450. Phosphorylation of phenobarbital-inducible P-450 forms PB-4 (IIB1) and PB-5 (IIB2) in isolated rat hepatocytes and in vivo

International Nuclear Information System (INIS)

Koch, J.A.; Waxman, D.J.

1989-01-01

Phosphorylation of hepatic cytochrome P-450 was studied in isolated hepatocytes incubated in the presence of agents known to stimulate protein kinase activity. Incubation of hepatocytes isolated from phenobarbital-induced adult male rats with [ 32 P]orthophosphate in the presence of N 6 , O 2' -dibutyryl-cAMP (diBtcAMP) or glucagon resulted in the phosphorylation of microsomal proteins that are immunoprecipitable by polyclonal antibodies raised to the phenobarbital-induced P-450 form PB-4 (P-450 gene IIB1). Two-dimensional gel electrophoresis revealed that these 32 P-labeled microsomal proteins consist of a mixture of P-450 PB-4 and the closely related P-450 PB-5 (gene IIB2), both of which exhibited heterogeneity in the isoelectric focusing dimension. Phosphorylation of both P-450 forms was markedly enhanced by diBtcAMP at concentrations as low as 5 μM. Phosphoamino acid analysis of the 32 P-labeled P-450 PB-4 + PB-5 immunoprecipitate revealed that these P-450s are phosphorylated on serine in the isolated hepatocytes. Peptide mapping indicated that the site of phosphorylation in hepatocytes is indistinguishable from the site utilized by cAMP-dependent protein kinase in vitro, which was previously identified as serine-128 for the related rabbit protein P-450 LM2. In vitro analyses revealed that phosphorylation of P-450 PB-4 leads to a loss of monooxygenase activity, suggesting that the posttranslational modification of this P-450 enzyme by cAMP-dependent protein kinase may play a role in the modulation of P-450-dependent monooxygenase activity in vivo

A Chinese Herbal Medicine, Jia-Wei-Xiao-Yao-San, Prevents Dimethylnitrosamine-Induced Hepatic Fibrosis in Rats

Directory of Open Access Journals (Sweden)

Shu-Chen Chien

2014-01-01

Full Text Available Jia-wei-xiao-yao-san (JWXYS is a traditional Chinese herbal medicine that is widely used to treat neuropsychological disorders. Only a few of the hepatoprotective effects of JWXYS have been studied. The aim of this study was to investigate the hepatoprotective effects of JWXYS on dimethylnitrosamine- (DMN- induced chronic hepatitis and hepatic fibrosis in rats and to clarify the mechanism through which JWXYS exerts these effects. After the rats were treated with DMN for 3 weeks, serum glutamic oxaloacetic transaminase (SGOT and serum glutamic pyruvic transaminase (SGPT levels were significantly elevated, whereas the albumin level decreased. Although DMN was continually administered, after the 3 doses of JWXYS were orally administered, the SGOT and SGPT levels significantly decreased and the albumin level was significantly elevated. In addition, JWXYS treatment prevented liver fibrosis induced by DMN. JWXYS exhibited superoxide-dismutase-like activity and dose-dependently inhibited DMN-induced lipid peroxidation and xanthine oxidase activity in the liver of rats. Our findings suggest that JWXYS exerts antifibrotic effects against DMN-induced chronic hepatic injury. The possible mechanism is at least partially attributable to the ability of JWXYS to inhibit reactive-oxygen-species-induced membrane lipid peroxidation.

Protective Effect of Ethyl Acetate Fraction of Stereospermum Suaveolens Against Hepatic Oxidative Stress in STZ Diabetic Rats

Directory of Open Access Journals (Sweden)

Thirumalaiswamy Balasubramanian

2013-07-01

Full Text Available Stereospermum suaveolens is a folk remedy for the treatment of diabetes and liver disorders in southern parts of India. In the present study, the protective effect of the ethyl acetate fraction of ethanol extract from S. suaveolens against hepatic oxidative stress was evaluated in streptozotocin (STZ-induced diabetic rats for 14 days. The ethyl acetate fraction was administered orally to the STZ diabetic rats at the doses of 200 and 400 mg/kg. Blood glucose level was measured according to glucose oxidase method. In order to determine hepatoprotective activity, changes in the levels of serum biomarker enzymes such as aspartate transaminase (AST, alanine transaminase (ALT, and serum alkaline phosphatase (SALP were assessed in the ethyl acetate fraction treated diabetic rats and were compared with the levels in diabetic control rats. In addition, the antioxidant activity of ethyl acetate fraction was evaluated using various hepatic parameters such as thiobarbituric acid reactive substances (TBARS, reduced glutathione (GSH, superoxide dismutase (SOD, and catalase (CAT. It was found that administration of ethyl acetate fraction (200 and 400 mg/kg produced a significant (P<0.001 fall in fasting blood glucose level, TBARS, bilirubin, AST, ALT, and SALP, while elevating the GSH levels, and SOD and CAT activities in diabetic rats. Histopathologic studies also revealed the protective effect of ethyl acetate fraction on the liver tissues of diabetic rats. It was concluded from this study that the ethyl acetate fraction from ethanol extract of S. suaveolens modulates the activity of enzymatic and nonenzymatic antioxidants and enhances the defense against hepatic oxidative stress in STZ-induced diabetic rats.

The antifibrotic effects of TGF-β1 siRNA on hepatic fibrosis in rats

International Nuclear Information System (INIS)

Lang, Qing; Liu, Qi; Xu, Ning; Qian, Ke-Li; Qi, Jing-Hu; Sun, Yin-Chun; Xiao, Lang; Shi, Xiao-Feng

2011-01-01

Highlights: → We constructed CCL4 induced liver fibrosis model successfully. → We proofed that the TGF-β1 siRNA had a definite therapy effect to CCL4 induced liver fibrosis. → The therapy effect of TGF-β1 siRNA had dose-dependent. -- Abstract: Background/aims: Hepatic fibrosis results from the excessive secretion of matrix proteins by hepatic stellate cells (HSCs), which proliferate during fibrotic liver injury. Transforming growth factor (TGF)-β1 is the dominant stimulus for extracellular matrix (ECM) production by stellate cells. Our study was designed to investigate the antifibrotic effects of using short interference RNA (siRNA) to target TGF-β1 in hepatic fibrosis and its mechanism in rats exposed to a high-fat diet and carbon tetrachloride (CCL4). Methods: A total of 40 healthy, male SD (Sprague-Dawley) rats were randomly divided into five even groups containing of eight rats each: normal group, model group, TGF-β1 siRNA 0.125 mg/kg treatment group, TGF-β1 siRNA 0.25 mg/kg treatment group and TGF-β1 siRNA negative control group (0.25 mg/kg). CCL4 and a high-fat diet were used for 8 weeks to induce hepatic fibrosis. All the rats were then sacrificed to collect liver tissue samples. A portion of the liver samples were soaked in formalin for Hematoxylin-Eosin staining, classifying the degree of liver fibrosis, and detecting the expression of type I and III collagen and TGF-β1; the remaining liver samples were stored in liquid nitrogen to be used for detecting TGF-β1 by Western blotting and for measuring the mRNA expression of type I and III collagen and TGF-β1 by quantitative real-time polymerase chain reaction. Results: Comparing the TGF-β1 siRNA 0.25 mg/kg treatment group to the model group, the TGF-β1 siRNA negative control group and the TGF-β1 siRNA 0.125 mg/kg treatment group showed significantly reduced levels of pathological changes, protein expression and the mRNA expression of TGF-β1, type I collagen and type III collagen (P < 0

The antifibrotic effects of TGF-{beta}1 siRNA on hepatic fibrosis in rats

Energy Technology Data Exchange (ETDEWEB)

Lang, Qing; Liu, Qi [Key Laboratory of Molecular Biology for Infectious Diseases, Ministry of Education, Instituted for Virus Hepatitis and Department of Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing (China); Xu, Ning [The Second Hospital of YuLin, Shanxi Province (China); Qian, Ke-Li; Qi, Jing-Hu; Sun, Yin-Chun; Xiao, Lang [Key Laboratory of Molecular Biology for Infectious Diseases, Ministry of Education, Instituted for Virus Hepatitis and Department of Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing (China); Shi, Xiao-Feng, E-mail: sxff2003@yahoo.com.cn [Key Laboratory of Molecular Biology for Infectious Diseases, Ministry of Education, Instituted for Virus Hepatitis and Department of Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing (China)

2011-06-10

Highlights: {yields} We constructed CCL4 induced liver fibrosis model successfully. {yields} We proofed that the TGF-{beta}1 siRNA had a definite therapy effect to CCL4 induced liver fibrosis. {yields} The therapy effect of TGF-{beta}1 siRNA had dose-dependent. -- Abstract: Background/aims: Hepatic fibrosis results from the excessive secretion of matrix proteins by hepatic stellate cells (HSCs), which proliferate during fibrotic liver injury. Transforming growth factor (TGF)-{beta}1 is the dominant stimulus for extracellular matrix (ECM) production by stellate cells. Our study was designed to investigate the antifibrotic effects of using short interference RNA (siRNA) to target TGF-{beta}1 in hepatic fibrosis and its mechanism in rats exposed to a high-fat diet and carbon tetrachloride (CCL4). Methods: A total of 40 healthy, male SD (Sprague-Dawley) rats were randomly divided into five even groups containing of eight rats each: normal group, model group, TGF-{beta}1 siRNA 0.125 mg/kg treatment group, TGF-{beta}1 siRNA 0.25 mg/kg treatment group and TGF-{beta}1 siRNA negative control group (0.25 mg/kg). CCL4 and a high-fat diet were used for 8 weeks to induce hepatic fibrosis. All the rats were then sacrificed to collect liver tissue samples. A portion of the liver samples were soaked in formalin for Hematoxylin-Eosin staining, classifying the degree of liver fibrosis, and detecting the expression of type I and III collagen and TGF-{beta}1; the remaining liver samples were stored in liquid nitrogen to be used for detecting TGF-{beta}1 by Western blotting and for measuring the mRNA expression of type I and III collagen and TGF-{beta}1 by quantitative real-time polymerase chain reaction. Results: Comparing the TGF-{beta}1 siRNA 0.25 mg/kg treatment group to the model group, the TGF-{beta}1 siRNA negative control group and the TGF-{beta}1 siRNA 0.125 mg/kg treatment group showed significantly reduced levels of pathological changes, protein expression and the m

Investigation of hepatic fibrosis in rats with x-ray diffraction enhanced imaging

International Nuclear Information System (INIS)

Li Hui; Zhang Lu; Wang Xueyan; Luo Shuqian; Wang Tailing; Wang Baoen; Zhao Xinyan

2009-01-01

X-ray diffraction enhanced imaging (DEI) is a phase contrast technique that generates excellent contrast of biological soft tissues compared to conventional absorption radiography. We explore the application of DEI in the diagnosis of hepatic fibrosis. The produced refraction contrast images of fibrous rat liver samples show clearly abnormal liver architectures. Moreover, by comparing to histological pictures, different stages of fibrosis are discriminated, and the corresponding morphological features are analyzed. Besides, quantitative analyses of texture features are presented. The results reported herein show that DEI can be a potential noninvasive technique to diagnose and stage hepatic fibrosis

Carvedilol suppresses circulating and hepatic IL-6 responsible for hepatocarcinogenesis of chronically damaged liver in rats

International Nuclear Information System (INIS)

Balaha, Mohamed; Kandeel, Samah; Barakat, Waleed

2016-01-01

Carvedilol is an anti-oxidant non-selective β-blocker used for reduction of portal blood pressure, prophylaxis of esophageal varices development and bleeding in chronic liver diseases. Recently, it exhibited potent anti-inflammatory, anti-fibrotic, anti-proliferative and anti-carcinogenic effects. In the present study, we evaluated the possible suppressive effect of carvedilol on circulating and hepatic IL-6 levels responsible for hepatocarcinogenesis in a rat model of hepatic cirrhosis. Besides, its effect on hepatic STAT-3 levels, function tests, oxidative stress markers, and hydroxyproline content, hepatic tissue histopathological changes and immunohistochemical expression of E & N-cadherin. Nine-week-old male Wistar rats injected intraperitoneal by 1 ml/kg 10% CCL 4 in olive oil three times/week (every other day) for 12 weeks to induce hepatic cirrhosis. Carvedilol (10 mg/kg/day suspended in 0.5% CMC orally), silymarin (50 mg/kg/day suspended in 0.5% CMC orally) or combination of both used to treat hepatic cirrhosis from 15th to 84th day. Our data showed that carvedilol and silymarin co-treatment each alone or in combination efficiently reduced the elevated serum IL-6, ALT, AST, ALP and BIL, hepatic IL-6, STAT-3, MDA levels and hydroxyproline content. In addition, it elevated the reduced serum ALB level, hepatic CAT activity and GSH level. Meanwhile, it apparently restored the normal hepatic architecture, collagen distribution and immunohistochemical E & N-cadherin expression. Furthermore, carvedilol was superior to silymarin in improving MDA level. Moreover, the combination of carvedilol and silymarin showed an upper hand in amelioration of the CCL 4 induced hepatotoxicity than each alone. Therefore, carvedilol could be promising in prevention of hepatocarcinogenesis in chronic hepatic injuries. - Highlights: • Chronic liver damage ends into hepatocellular carcinoma in 5% of patients. • Persistent elevation of IL-6 induces hepatocarcinogenesis in chronic

Carvedilol suppresses circulating and hepatic IL-6 responsible for hepatocarcinogenesis of chronically damaged liver in rats

Energy Technology Data Exchange (ETDEWEB)

Balaha, Mohamed, E-mail: Mohamed.Balaha@Med.Tanta.Edu.Eg [Pharmacology Department, Faculty of Medicine, Tanta University, El-Gish Street, Postal No. 31527 Tanta (Egypt); Kandeel, Samah [Histology Department, Faculty of Medicine, Tanta University, El-Gish Street, Postal No. 31527 Tanta (Egypt); Barakat, Waleed [Pharmacology Department, Faculty of Medicine, Tanta University, El-Gish Street, Postal No. 31527 Tanta (Egypt)

2016-11-15

Carvedilol is an anti-oxidant non-selective β-blocker used for reduction of portal blood pressure, prophylaxis of esophageal varices development and bleeding in chronic liver diseases. Recently, it exhibited potent anti-inflammatory, anti-fibrotic, anti-proliferative and anti-carcinogenic effects. In the present study, we evaluated the possible suppressive effect of carvedilol on circulating and hepatic IL-6 levels responsible for hepatocarcinogenesis in a rat model of hepatic cirrhosis. Besides, its effect on hepatic STAT-3 levels, function tests, oxidative stress markers, and hydroxyproline content, hepatic tissue histopathological changes and immunohistochemical expression of E & N-cadherin. Nine-week-old male Wistar rats injected intraperitoneal by 1 ml/kg 10% CCL{sub 4} in olive oil three times/week (every other day) for 12 weeks to induce hepatic cirrhosis. Carvedilol (10 mg/kg/day suspended in 0.5% CMC orally), silymarin (50 mg/kg/day suspended in 0.5% CMC orally) or combination of both used to treat hepatic cirrhosis from 15th to 84th day. Our data showed that carvedilol and silymarin co-treatment each alone or in combination efficiently reduced the elevated serum IL-6, ALT, AST, ALP and BIL, hepatic IL-6, STAT-3, MDA levels and hydroxyproline content. In addition, it elevated the reduced serum ALB level, hepatic CAT activity and GSH level. Meanwhile, it apparently restored the normal hepatic architecture, collagen distribution and immunohistochemical E & N-cadherin expression. Furthermore, carvedilol was superior to silymarin in improving MDA level. Moreover, the combination of carvedilol and silymarin showed an upper hand in amelioration of the CCL{sub 4} induced hepatotoxicity than each alone. Therefore, carvedilol could be promising in prevention of hepatocarcinogenesis in chronic hepatic injuries. - Highlights: • Chronic liver damage ends into hepatocellular carcinoma in 5% of patients. • Persistent elevation of IL-6 induces hepatocarcinogenesis

[Comparative metabolism of three amide alkaloids from Piper longum in five different species of liver microsomes].

Science.gov (United States)

He, Huan; Guo, Wei-Wei; Chen, Xiao-Qing; Zhao, Hai-Yu; Wu, Xia

2016-08-01

Piperine, piperlonguminine and pellitorine are three major amide alkaloids from Piper longum, showing a variety of pharmacological activities. In order to investigate the different metabolism pathways of these compounds in five species of liver microsomes in vitro, the data of full mass spectrum, and MS2, MS3 spectra of these three alkaloids were collected and analyzed by using ultra-high-performance liquid chromatography coupled with a LTQ-orbitrap mass spectrometer (UHPLC-LTQ-Orbitrap MS); gragment ion information was collected and combined with fragmentation regularities of mass spectra and accurate mass spectrometry data of metabolites, to compare the metabolism difference of three amide alkaloids in liver microsomes of human, rhesus monkey, Beagle dogs, rats and mice. 3 metabolites of piperine, 2 metabolites of piperlonguminine and 1 metabolite of pellitorine were identified quickly. The results showed that the major metabolic pathways of these amide alkaloids in liver microsomes were methylenedioxy group demethylation and oxidation reaction, and metabolic rates were different between species. This study provides basis for further research on in vivo metabolism of piperine analogues from Piper longum. Copyright© by the Chinese Pharmaceutical Association.

Detection on immunoblot of new proteins from the soluble fraction of the cell recognized either by anti-liver-kidney microsome antibodies type 1 or by anti-liver cytosol antibodies type 1--relationship with hepatitis C virus infection.

Science.gov (United States)

Ballot, E; Desbos, A; Monier, J C

1996-09-01

Antibodies directed against liver cytosol protein, called anti-liver cytosol type 1 (LC1 Ab), have been described by both immunofluorescence (IF) and immunodiffusion techniques in sera from patients with autoimmune hepatitis (AIH). They have never been found in association with antibodies directed against the hepatitis C virus (HCV), unlike the anti-liver-kidney microsome antibodies type 1 (LKM1 Ab), the serological marker of AIH type 2. This suggests that there are two subgroups of AIH type 2, i.e., HCV-related and non-HCV-related. In this study, immunoblotting experiments were performed using proteins from the soluble phase of the rat liver cell; 141 sera which tested positive for LKM1 Ab by IF, 24 identified as having LC1 Ab by IF, and 50 from blood donors as controls were analyzed. Three bands were stained by LC1 Ab sera more often than by the control sera, and with a statistically significant frequency. These 3 proteins were located at apparent Mr 50,000, 55,000, and 60,000. The LKM1 Ab-positive sera as defined by IF stained six bands with a statistically significant frequency compared to the controls. Their apparent Mr were 35,000, 39,000, 47,000, 50,000, 55,000, and 60,000. LKM1 Ab-positive sera which were anti-HCV negative recognized a 60,000 protein belonging to the soluble phase of the cell, with a statistically significant frequency compared to LKM1 Ab-positive sera which were anti-HCV positive. This 60,000 protein was also recognized by LC1 Ab-positive sera, which were almost always anti-HCV negative. The presence of antibodies against a 60,000 protein from the soluble phase of the cell is discussed in terms of the anti-HCV serological markers found in the sera from patients with AIH.

Metabolism of fatty acids in rat brain in microsomal membranes

International Nuclear Information System (INIS)

Aeberhard, E.E.; Gan-Elepano, M.; Mead, J.F.

1980-01-01

Using a technique in which substrate fatty acids are incorporated into microsomal membranes followd by comparison of their rates of desaturation or elongation with those of exogenous added fatty acids it has been found that the desaturation rate is more rapid for the membrane-bound substrate than for the added fatty acid. Moreover, the product of the membrane-bound substrate is incorporated into membrane phospholipid whereas the product of the exogenous substrate is found in di- and triacyl glycerols and in free fatty acids as well. These and other findings point to a normal sequence of reaction of membrane liqids with membrane-bound substrates involving transfer of fatty acid from phospholipid to the coupled enzyme systems without ready equilibration with the free fatty acid pool

Studies on the toxic interaction between monensin and tiamulin in rats: effects on P450 activities.

Science.gov (United States)

Szücs, G; Laczay, P; Bajnógel, J; Móra, Z

2000-01-01

Studies were carried out to investigate the effects of monensin and tiamulin, and the simultaneous administration of both compounds on microsomal enzymes in rats. In Phase I of the experiments the effects of monensin and tiamulin were studied separately (monensin 10, 30, and 50 mg/kg or tiamulin 40, 120, and 200 mg/kg body weight, respectively), while in Phase II the two compounds were administered simultaneously (monesin 10 mg/kg and tiamulin 40 mg/kg b.w., respectively). When monensin was administered by itself, it exerted no significant effect on microsomal liver enzymes. In a few cases, slight inhibition of certain enzyme activities was seen. Tiamulin provoked a dose-dependent hepatic enzyme induction. The combined administration of monensin and tiamulin at low doses (10 and 40 mg/kg, respectively) resulted in marked elevation of P450-related enzyme activities. The enzyme induction was more pronounced in females than in males. The results suggest that the simultaneous administration of tiamulin may influence the biotransformation of monensin, possibly increasing the amount of reactive metabolite(s) of the ionophore antibiotic.

Black Seed Thymoquinone Improved Insulin Secretion, Hepatic Glycogen Storage, and Oxidative Stress in Streptozotocin-Induced Diabetic Male Wistar Rats

Directory of Open Access Journals (Sweden)

Heba M. A. Abdelrazek

2018-01-01

Full Text Available Diabetes mellitus is one of the metabolic diseases having several complications. Nigella sativa oil (NSO might have beneficial effects in the treatment of diabetic complications. Thirty-two mature male Wistar rats were equally divided into four experimental groups: control, control NSO 2 mL/kg, streptozotocin- (STZ- induced diabetic, and diabetic (STZ-induced treated with oral NSO 2 mg/kg for 30 days. Fasting blood glucose (FBG, insulin, and lipid profile levels were determined. Pancreatic and hepatic tissues were used for catalase and GSH. Histopathology, hepatic glycogen contents, insulin immunohistochemistry, and pancreatic islet morphometry were performed. NSO 2 mL/kg was noticed to decrease (P<0.05 FBG and increase (P<0.05 insulin levels in diabetic rats than in diabetic nontreated animals. Lipid profile showed significant (P<0.5 improvement in diabetic rats that received NSO 2 mL/kg than in the diabetic group. Both pancreatic and hepatic catalase and GSH activities revealed a significant (P<0.05 increment in the diabetic group treated with NSO than in the diabetic animals. NSO improved the histopathological picture and hepatic glycogen contents of the diabetic group as well as increased (P<0.05 insulin immunoreactive parts % and mean pancreatic islet diameter. NSO exerts ameliorative and therapeutic effects on the STZ-induced diabetic male Wistar rats.

Methimazole protects lungs during hepatic ischemia-reperfusion injury in rats: an effect not induced by hypothyroidism.

Science.gov (United States)

Tütüncü, Tanju; Demirci, Cagatay; Gözalan, Ugur; Yüksek, Yunus Nadi; Bilgihan, Ayse; Kama, Nuri Aydin

2007-05-01

Hepatic ischemia-reperfusion injury may lead to remote organ failure with mortal respiratory dysfunction. The aim of the present study was to analyze the possible protective effects of methimazole on lungs after hepatic ischemia-reperfusion injury. Forty male Wistar albino rats were randomized into five groups: a control group, in which bilateral pulmonary lobectomy was done; a hepatic ischemia-reperfusion group, in which bilateral pulmonary lobectomy was done after hepatic ischemia-reperfusion; a thyroidectomy-ischemia-reperfusion group (total thyroidectomy followed by, 7 days later, bilateral pulmonary lobectomy after hepatic ischemia-reperfusion); a methimazole-ischemia-reperfusion group (following methimazole administration for 7 days, bilateral pulmonary lobectomy was done after hepatic ischemia-reperfusion); and a methimazole +L-thyroxine-ischemia-reperfusion group (following methimazole and L-thyroxine administration for 7 days, bilateral pulmonary lobectomy was performed after hepatic ischemia-reperfusion). Pulmonary tissue specimens were evaluated histopathologically and for myeloperoxidase and malondialdehyde levels. All of the ischemia-reperfusion intervention groups had higher pulmonary injury scoring indices than the control group (P < 0.001). Pulmonary injury index of the ischemia-reperfusion group was higher than that of both the methimazole-supplemented hypothyroid and euthyroid groups (P = 0028; P = 0,038, respectively) and was similar to that of the thyroidectomized group. Pulmonary tissue myeloperoxidase and malondialdehyde levels in the ischemia-reperfusion group were similar with that in the thyroidectomized rats but were significantly higher than that in the control, and both the methimazole-supplemented hypothyroid and euthyroid groups. Methimazole exerts a protective role on lungs during hepatic ischemia-reperfusion injury, which can be attributed to its anti-inflammatory and anti-oxidant effects rather than hypothyroidism alone.

Radioprotection of liver lipids of whole-body gamma-irradiated female rats by cystamine

International Nuclear Information System (INIS)

Ramanathan, R.; Misra, U.K.

1976-01-01

The effect of administration of cystamine (5 mg/100 g body weight) before 1,200 R whole-body gamma irradiation has been studied on irradiation-induced changes in liver and its subcellular fractions'lipids of fasted female rats. Cystamine prevented the irradiation-induced increase in liver triglycerides and liver mitochondrial total phospholipids, but it decreased microsomal total phospholipids and proteins. Cystamine prevented the radiation-induced increased 32 P-radioactivity (counts/min/μmole phospholipid phosphorus) of microsomal phosphatidyl choline. Cystamine prevented the radiation-induced increased uptake of NaH 2 32 PO 4 (counts/min/g liver) in liver microsomal phosphatidyl ethanolamine and supernatant phosphatidyl choline; but in microsomal phosphatidyl choline, cystamine did not do so, but on the other hand it itself increased the uptake in control rats. Cystamine did not prevent the irradiation-induced decreased incorporation of (U- 14 C)glucose into liver triglycerides, total phospholipids and phosphatidyl choline. Cystamine itself decreased the incorporation of (U- 14 C)glucose into liver triglycerides and phosphoglycerides of control rats. (orig.) [de

Hepatic Cyp1a2 Expression Reduction during Inflammation Elicited in a Rat Model of Intermittent Hypoxia

Directory of Open Access Journals (Sweden)

Li-Xia Shi

2017-01-01

Conclusions: These results indicate a decrease in expression of hepatic CYPs and their regulator GR in rats exposed to IH. Therefore, this should be noted for patients on medication, especially those on drugs metabolized via the hepatic system, and close attention should be paid to the liver function of patients with OSA-associated IH.

Nuclear ploidy of neonatal rat livers: effects of two hepatic carcinogens (mirex and dimethylnitrosamine)

International Nuclear Information System (INIS)

Carlson, J.; Abraham, R.

1985-01-01

The effect of two hepatic carcinogens, dimethylnitrosamine (DMN) (genotoxic) and mirex (epigenetic), on polyploidization in 12-d-old neonatal rats was investigated by Coulter counteranalysis and [ 3 H] thymidine uptake in isolated hepatic nuclear classes. DMN disturbed the normal ploidy development in the neonatal liver and the proportion of nuclei in the ploidy classes by inducing the premature formation of a significant population of tetraploids with a concommitant reduction in diploids. A great proportion of the replicative activity was present in tetraploid nuclei as measured by the incorporation of [ 3 H] thymidine. The labeling index and number of mitoses were also increased. In contrast to DMN, mirex had no influence on polyploidization. The neonatal rats used in these studies thus offer an opportunity to investigate in vivo the mode of action of genotoxic versus epigenetic compounds with reference to their effect on DNA

UPLC/MS MS data of testosterone metabolites in human and zebrafish liver microsomes and whole zebrafish larval microsomes

Directory of Open Access Journals (Sweden)

Moayad Saad

2018-02-01

Full Text Available This article represents data regarding a study published in Toxicology in vitro entitled “ in vitro CYP-mediated drug metabolism in the zebrafish (embryo using human reference compounds” (Saad et al., 2017 [1]. Data were acquired with ultra-performance liquid chromatography – accurate mass mass spectrometry (UPLC-amMS. A full spectrum scan was conducted for the testosterone (TST metabolites from the microsomal stability assay in zebrafish and humans. The microsomal proteins were extracted from adult zebrafish male (MLM and female (FLM livers, whole body homogenates of 96 h post fertilization larvae (EM and a pool of human liver microsomes from 50 donors (HLM. Data are expressed as the abundance from the extracted ion chromatogram of the metabolites.

Oxidative metabolism of monensin in rat liver microsomes and interactions with tiamulin and other chemotherapeutic agents: evidence for the involvement of cytochrome P-450 3A subfamily.

Science.gov (United States)

Nebbia, C; Ceppa, L; Dacasto, M; Carletti, M; Nachtmann, C

1999-09-01

Monensin (MON) is an ionophore antibiotic widely used in veterinary practice as a coccidiostatic or a growth promoter. The aims of this study were to characterize the P-450 isoenzyme(s) involved in the biotransformation of the ionophore and to investigate how this process may be affected by tiamulin and other chemotherapeutic agents known to produce toxic interactions with MON when administered concurrently in vivo. In liver microsomes from untreated rats (UT) or from rats pretreated, respectively, with ethanol (ETOH), beta-naphthoflavone (betaNAF), phenobarbital (PB), pregnenolone 16alpha-carbonitrile (PCN), or dexamethasone (DEX), the rate of MON O-demethylation was the following: DEX > PCN > PB > UT = ETOH > betaNAF; similar results were obtained by measuring total MON metabolism. In addition, the extent of triacetyloleandomycin-mediated P-450 complexes was greatly reduced by the prior addition of 100 microM MON. In DEX-treated microsomes, MON O-demethylation was found to fit monophasic Michaelis-Menten kinetics (K(M) = 67.6 +/- 0.01 microM; V(max) = 4.75 +/- 0.76 nmol/min/mg protein). Tiamulin markedly inhibited this activity in an apparent competitive manner, with a calculated K(i) (Dixon plot) of 8.2 microM and an IC(50) of about 25 microM. At the latter concentration, only ketoconazole or metyrapone, which can bind P-450 3A, inhibited MON O-demethylase to a greater extent than tiamulin, whereas alpha-naphthoflavone, chloramphenicol, or sulphametasine was less effective. These results suggest that P-450 3A plays an important role in the oxidative metabolism of MON and that compounds capable of binding or inhibiting this isoenzyme could be expected to give rise to toxic interactions with the ionophore.

Stereospecificity (ST) of the microsomal ethanol oxidizing system (MEOS)

International Nuclear Information System (INIS)

Alderman, J.; Kato, S.; Lasker, J.; Lieber, C.S.

1987-01-01

The ST of MEOS for the ethanol 1R hydrogen has been variously reported as absolute, partial or absent, with free radical involvement postulated in the latter case. To determine both the ST of MEOS and the participation of free radicals in the reaction, they investigated MEOS ST using 1R[1- 3 H] ethanol as substrate. ST is expressed as the fraction of 3 H labeling in acetaldehyde formed, relative to that in ethanol, and ranges from 0.5 to 0. Partial ST was observed using liver microsomes from both rats and hamsters; it significantly decreased after ethanol feeding. 0.1 mM desferrioxamine (dfx) did not increase ST in any of these microsomal preparations while ferric EDTA decreased it, suggesting that ethanol treatment induces a cytochrome P-450 with lower ST rather than increasing free radical involvement. This is supported by a virtual absence of ST observed in a reconstituted system containing purified hamster P-450/sub ALC/, a liver cytochrome P-450 isozyme induced in hamsters by ethanol treatment. Their results indicate that, unlike other enzymes that oxidize ethanol, MEOS has only partial ST. Thus, ST alone cannot be used as an index of free radical involvement but, when evaluated with the response of ST to dfx, it indicated that MEOS is unlikely to involve free radical attack on ethanol in solution

Effects of perfluorodecanoic(PFDA) and perfluorooctanoic (PFOA) acids on hepatic carnitine palmitoyltransferase (CPT) activity in rats

International Nuclear Information System (INIS)

Vanden Heuvel, J.P.; Kuslikis, B.I.; Peterson, R.E.

1990-01-01

PFDA has been hypothesized to cause a diversion of fatty acids from oxidation toward esterification in rat liver. Normal regulation of this partitioning is exerted by CPT, an enzyme inhibited by several peroxisome proliferators. Effects of the peroxisome proliferators PFDA and PFOA on hepatic mitochondrial fatty acid oxidation and CPT activity were examined. PFDA or PFOA added to isolated rat liver mitochondria in concentrations of 0.2, 2, 20 and 200 μg per mg mitochondrial protein had no effect on CPT activity nor on mitochondrial oxidation of [1- 14 C] palmitoyl-CoA or [1- 14 C] palmitoyl-carnitine (quantitated by 14 CO 2 plus acid soluble 14 C production). Three days after rats were treated with PFDA or PFOA (37.5 or 150 μmol/kg, ip) or vehicle, liver mitochondria were isolated. Mitochondrial oxidation of [1- 14 C] palmitoyl-CoA or [1- 14 C]palmitoyl-carnitine was unaffected by PFDA and PFOA. CPT activity and inhibition of CPT activity by malonyl-CoA was also unaffected by PFDA and PFOA. Therefore, PFDA and PFOA did not have a major inhibitory effect on hepatic mitochondrial oxidation of palmitoyl-CoA or palmitoyl-carnitine, nor did they interfere with hepatic CPT activity either in vitro or in vivo

Delayed plasma clearance and hepatic uptake of lymph chylomicron 14C-cholesterol in marginally zinc-deficient rats

International Nuclear Information System (INIS)

Koo, S.I.; Algilani, K.; Norvell, J.E.; Henderson, D.A.

1986-01-01

Previously, chylomicrons from marginally zinc-deficient rats were shown to be abnormally large, with markedly reduced levels of apoproteins C and E. In the present study, effects of such changes on the plasma clearance and hepatic uptake of chylomicron cholesterol were investigated in rats fed 3 ppm of zinc (ZD), as compared with those fed 30 ppm of zinc (CT). The rate of plasma clearance was determined by plasma 14C-radioactivity at different intervals after intravenous injection of lymph chylomicrons labeled in vivo with 14C-cholesterol. The 14C-clearance curves were nonlinear, consisting of an initial rapid phase followed by a slow phase of clearance. The initial 14C-clearance was significantly (p less than 0.05) delayed whether the labeled chylomicrons from ZD donors were injected into ZD or CT recipients. The hepatic 14C-recovery in extracted lipids was also significantly lower in ZD rats. The present data provide first evidence that a marginal level of zinc deficiency produces a significant delay in the plasma clearance and hepatic uptake of chylomicron cholesterol. This may be attributable in part to the molecular alterations of chylomicrons induced by zinc deficiency

Influence of chronic stress on the compositions of hepatic cholesterol and triglyceride in male Wistar rats fed a high fat diet.

Science.gov (United States)

Gao, Siyuan; Han, Xue; Fu, Jihua; Yuan, Xiaoling; Sun, Xing; Li, Qiang

2012-07-01

  We determined the influence of chronic stress (CS) on the compositions of hepatic cholesterol and triglyceride (TG) in rats fed a high fat diet (HFD).   Male Wistar rats were fed either a standard diet or a HFD and half of the HFD fed rats were given CS (electric foot shock assisted with noise) for 8 weeks.   Compared with the control group, the levels of hepatic total cholesterol (TC) and TG were significantly elevated in the HFD and HFD with chronic stress (HFD+CS) groups, and the more severe elevations of them were found in the HFD group. Inversely, the more severe elevations of hepatic water-soluble parts of TC and TG were found in the HFD+CS group, as the elevations of low-density lipoprotein cholesterol, very low-density lipoprotein cholesterol in liver and serum, tumor necrosis factor-α, interleukin-1β and malondialdehyde in liver. Meanwhile, downregulated mRNA expressions of hepatic liver X receptor-α (LXR-α) and peroxisome proliferator-activated receptor-γ (PPAR-γ) were also more severe in the HFD+CS group.   CS can aggravate the high levels of water-soluble compositions of hepatic TC and TG induced by HFD as it aggravates hepatic inflammation and oxidative stress; in spite of that, however, it cannot further promote hepatic lipidosis. This is consistent with the downregulated mRNA expressions of LXR-α and PPAR-γ. © 2012 The Japan Society of Hepatology.

Relation between blood clearance and hepatic uptake of sup 99m Tc-phytate in rats with hepatic injury

Energy Technology Data Exchange (ETDEWEB)

Shibata, Hiroshi; Hisano, Tomoyuki; Kohno, Masahiro (Yamaguchi University, Ube (Japan). Faculty of Agriculture)

1989-10-01

The relation among the blood clearance of {sup 99m}Tc-phytake ({sup 99m}Tc-P), the hepatic uptake of {sup 99m}Tc-P and the severity of hepatic injury was investigated by using the rats with carbon tetrachloride (CCL{sub 4}), D-galactosamine (Gal N), alpha-naphthylisothiocyanate (ANIT) or DL-ethionine (EthN) induced hepatic injury. After the administration of CCL{sub 4}, GalN or ANIT, serum GPT activity increased significantly with the increase of dose level, and the degree of this increase was in the order: GalN>CCl{sub 4}>ANIT. However, the mild increase in serum GPT activity was observed after EthN administration. The blood clearance rate of {sup 99m}Tc-P and the hepatic uptake ratio of {sup 99m}Tc-P decreased with the increase of dose level after CCl{sub 4}, GalN or ANIT administration, but significant changes were not found after EthN administration. The degree of decrease in the blood clearance rate of {sup 99m}Tc-P was in the order: GalNapproxCCl{sub 4}>ANIT, and the degree of decrease in the hepatic uptake ratio of {sup 99m}Tc-P was in the order: GalNapproxCCl{sub 4}>ANIT. These results suggest that the disorder in the hepatocytes may be one of causes for inducing the decrease in the hepatic uptake of {sup 99m}Tc-P, and the consequence of this decrease may induce the decrease in the blood clearance of {sup 99m}Tc-P. (author).

LKM3 autoantibodies in hepatitis C cirrhosis: a further phenomenon of the HCV-induced autoimmunity.

Science.gov (United States)

Csepregi, A; Nemesánszky, E; Luettig, B; Obermayer-Straub, P; Manns, M P

2001-03-01

Chronic hepatitis C is frequently associated with laboratory markers-including LKM1 autoantibodies--of autoimmunity. A 62-yr-old woman with hepatitis C cirrhosis presented autoantibodies against liver and kidney microsomal proteins. By further evaluation of autoantibodies using ELISA and immunoblotting LKM1 and LKM3 autoantibodies could be revealed. The target antigen of LKM3 autoantibodies proved to be UGT-1.1 isoenzyme. In the absence of chronic hepatitis D infection or autoimmune hepatitis type 2, this is the first case that reports the occurrence of LKM3 autoantibodies in HCV-induced chronic liver disease.

Cholesterol biosynthesis in polychlorinated biphenyl-treated rats

International Nuclear Information System (INIS)

Kling, D.; Gamble, W.

1982-01-01

After administration of polychlorinated biphenly (PCB) at 0.055 (w/w) of the diet to Wistar rats for 30 days, followed by intraperitioneal injection of tritiated water, [ 14 C]mevalonate, and [ 14 C]acetate, there was a decrease in cholesterol biosynthesis in rat liver. No significant change in cholesterol formation was observed when PCB was administered at 0.01% (w/w) of the diet. In vitro inhibition of cholesterol synthesis by rat liver microsomes was observed with PCB. Squalene 2,3-oxidocyclase activity of rat liver microsomes was not significantly altered. Desmosterol delta 24 reductase activity was inhibited only at relatively high concentrations of PCB. There was increased incorporation of radioactivity into squalene and lanosterol, in vitro, in the presence of PCB. The primary inhibition of cholesterol biosynthesis appears to be at the demethylation and rearrangement reactions between lanosterol and cholesterol in the biosynthetic pathway

The iron-responsive microsomal proteome of Aspergillus fumigatus.

Science.gov (United States)

Moloney, Nicola M; Owens, Rebecca A; Meleady, Paula; Henry, Michael; Dolan, Stephen K; Mulvihill, Eoin; Clynes, Martin; Doyle, Sean

2016-03-16

Aspergillus fumigatus is an opportunistic fungal pathogen. Siderophore biosynthesis and iron acquisition are essential for virulence. Yet, limited data exist with respect to the adaptive nature of the fungal microsomal proteome under iron-limiting growth conditions, as encountered during host infection. Here, we demonstrate that under siderophore biosynthetic conditions--significantly elevated fusarinine C (FSC) and triacetylfusarinine C (TAFC) production (pproteome remodelling occurs. Specifically, a four-fold enrichment of transmembrane-containing proteins was observed with respect to whole cell lysates following ultracentrifugation-based microsomal extraction. Comparative label-free proteomic analysis of microsomal extracts, isolated following iron-replete and -deplete growth, identified 710 unique proteins. Scatterplot analysis (MaxQuant) demonstrated high correlation amongst biological replicates from each growth condition (Pearson correlation >0.96 within groups; biological replicates (n=4)). Quantitative and qualitative comparison revealed 231 proteins with a significant change in abundance between the iron-replete and iron-deplete conditions (pAspergillus fumigatus must acquire iron to facilitate growth and pathogenicity. Iron-chelating non-ribosomal peptides, termed siderophores, mediate iron uptake via membrane-localised transporter proteins. Here we demonstrate for the first time that growth of A. fumigatus under iron-deplete conditions, concomitant with siderophore biosynthesis, leads to an extensive remodelling of the microsomal proteome which includes significantly altered levels of 231 constituent proteins (96 increased and 135 decreased in abundance), many of which have not previously been localised to the microsome. We also demonstrate the first synthesis of a fluorescent version of fusarinine C, an extracellular A. fumigatus siderophore, and its uptake and localization under iron-restricted conditions. This infers the use of an A. fumigatus

The tobacco carcinogen NNK is stereoselectively reduced by human pancreatic microsomes and cytosols.

Science.gov (United States)

Trushin, Neil; Leder, Gerhard; El-Bayoumy, Karam; Hoffmann, Dietrich; Beger, Hans G; Henne-Bruns, Doris; Ramadani, Marco; Prokopczyk, Bogdan

2008-07-01

Cigarette smoking increases the risk of cancer of the pancreas. The tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is the only known environmental compound that induces pancreatic cancer in laboratory animals. Concentrations of NNK are significantly higher in the pancreatic juice of smokers than in that of nonsmokers. The chiral NNK metabolite, (R,S)-4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) is itself a potent pancreatic carcinogen in rats. The carcinogenicity of NNAL is related to its stereochemistry; (S)-NNAL is a more potent lung tumorigen in the A/J mouse than is (R)-NNAL. In this study, we determined the potential of the human pancreas to convert NNK into NNAL. Human pancreatic microsomes and cytosols were incubated with [5-(3)H]NNK, and the metabolic products were determined by high-performance liquid chromatography (HPLC). (S)-NNAL was the predominant isomer formed in all cytosolic incubations. In ten microsomal samples, NNAL was formed at an average rate of 3.8 +/- 1.6 pmol/mg/min; (R)-NNAL was the predominant isomer in this group. The average rate of NNAL formation in 18 other microsomal samples was significantly lower, 0.13 +/- 0.12 pmol/mg/min (p < 0.001); (S)-NNAL was the predominant isomer formed in this group. In human pancreatic tissues, there is intraindividual variability regarding the capacity for, and stereoselectivity of, carbonyl reduction of NNK.

Effect of selective versus non-selective cyclooxygenase inhibitors on ischemia-reperfusion-induced hepatic injury in rats.

Science.gov (United States)

Abdel-Gaber, Seham A; Ibrahim, Mohamed A; Amin, Entesar F; Ibrahim, Salwa A; Mohammed, Rehab K; Abdelrahman, Aly M

2015-08-01

Ischemia-reperfusion (IR) injury represents an important pathological process of liver injury during major hepatic surgery. The role of cyclooxygenase (COX) enzymes in the pathogenesis of ischemia-reperfusion (IR)-induced liver injury is not clear. This study investigated the effect of a selective COX-2 inhibitor, celecoxib, versus non-selective, indomethacin, on hepatic IR injury in rats. Hepatic IR was induced in adult male rats. The animals were divided into 4 groups: normal control (sham group), IR non-treated group; IR-indomethacin-treated group; and IR-celecoxib-treated group. Liver injury was evaluated by serum alanine aminotransferase (ALT) and a histopathological examination of liver tissues. Hepatic tissue content of oxidative stress parameters glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase, malondialdehyde (MDA), nitric oxide (NO) and the inflammatory marker, tumor necrosis factor-alpha, (TNF-α) were measured. Moreover, the immunohistochemical detection of endothelial NO synthase (eNOS), inducible NO synthase (iNOS), and caspase-3 in the hepatic tissue was performed. Celecoxib, but not indomethacin, significantly attenuated hepatic IR injury as evidenced by reduction in serum ALT as well as by improvement in the histopathological scoring. Such effect was associated with attenuation in oxidative stress and TNF-α, along with modulation of immunohistochemical expression of eNOS, iNOS and caspase-3 in the hepatic tissue. The present study concluded that selective COX-2 inhibition (but not non-selective), is hepatoprotective against liver IR injury; indicating a differential role of COX-1 versus COX-2. Modulation of iNOS, eNOS and caspase-3 might participate in the protective effect of selective COX-2-inhibitors. Copyright © 2015 Elsevier Inc. All rights reserved.

Use of unripe plantain (Musa paradisiaca) in the management of diabetes and hepatic dysfunction in streptozotocin induced diabetes in rats.

Science.gov (United States)

Eleazu, Chinedum O; Okafor, Polycarp

2015-03-01

This study aims to investigate the effect of unripe plantain (Musa paradisiaca) on markers of hepatic dysfunction in streptozotocin induced diabetic rats. Blood glucose; relative liver weight (RLW); relative kidney weight (RKW); relative heart weight (RHW); relative pancreatic weight (RPW); serum and hepatic serum aspartate transaminase (AST), alanine transaminase (ALT), and alkaline phosphatase (ALP); serum amylase, lipase, total, and conjugated bilirubin; and chemical analysis of the test feed were determined using standard techniques. The diabetic rats had significant alteration (P 0.05) in the RHW of the rats in the three groups, as well as significant decreases (P 0.05) in the amylase levels of the rats fed unripe plantain compared with the nondiabetic rats. The test and standard rat feeds contained considerable amount of proteins, carbohydrates, fats, phenols, and crude fiber. Amelioration of acute pancreatitis by unripe plantain could play a key role in its management of diabetes and related complications.

3,5 Diiodo-L-Thyronine (T2 Does Not Prevent Hepatic Steatosis or Insulin Resistance in Fat-Fed Sprague Dawley Rats.

Directory of Open Access Journals (Sweden)

Daniel F Vatner

Full Text Available Thyroid hormone mimetics are alluring potential therapies for diseases like dyslipidemia, nonalcoholic fatty liver disease (NAFLD, and insulin resistance. Though diiodothyronines are thought inactive, pharmacologic treatment with 3,5- Diiodo-L-Thyronine (T2 reportedly reduces hepatic lipid content and improves glucose tolerance in fat-fed male rats. To test this, male Sprague Dawley rats fed a safflower-oil based high-fat diet were treated with T2 (0.25 mg/kg-d or vehicle. Neither 10 nor 30 days of T2 treatment had an effect on weight, adiposity, plasma fatty acids, or hepatic steatosis. Insulin action was quantified in vivo by a hyperinsulinemic-euglycemic clamp. T2 did not alter fasting plasma glucose or insulin concentration. Basal endogenous glucose production (EGP rate was unchanged. During the clamp, there was no difference in insulin stimulated whole body glucose disposal. Insulin suppressed EGP by 60% ± 10 in T2-treated rats as compared with 47% ± 4 suppression in the vehicle group (p = 0.32. This was associated with an improvement in hepatic insulin signaling; insulin stimulated Akt phosphorylation was ~2.5 fold greater in the T2-treated group as compared with the vehicle-treated group (p = 0.003. There was no change in expression of genes thought to mediate the effect of T2 on hepatic metabolism, including genes that regulate hepatic lipid oxidation (ppara, carnitine palmitoyltransferase 1a, genes that regulate hepatic fatty acid synthesis (srebp1c, acetyl coa carboxylase, fatty acid synthase, and genes involved in glycolysis and gluconeogenesis (L-pyruvate kinase, glucose 6 phosphatase. Therefore, in contrast with previous reports, in Sprague Dawley rats fed an unsaturated fat diet, T2 administration failed to improve NAFLD or whole body insulin sensitivity. Though there was a modest improvement in hepatic insulin signaling, this was not associated with significant differences in hepatic insulin action. Further study will be

Rapid and accurate liquid chromatography and tandem mass spectrometry method for the simultaneous quantification of ten metabolic reactions catalyzed by hepatic cytochrome P450 enzymes.

Science.gov (United States)

Shi, Rong; Ma, Bingliang; Wu, Jiasheng; Wang, Tianming; Ma, Yueming

2015-10-01

The hepatic cytochrome P450 enzymes play a central role in the biotransformation of endogenous and exogenous substances. A sensitive high-throughput liquid chromatography with tandem mass spectrometry assay was developed and validated for the simultaneous quantification of the products of ten metabolic reactions catalyzed by hepatic cytochrome P450 enzymes. After the substrates were incubated separately, the samples were pooled and analyzed by liquid chromatography with tandem mass spectrometry using an electrospray ionization source in the positive and negative ion modes. The method exhibited linearity over a broad concentration range, insensitivity to matrix effects, and high accuracy, precision, and stability. The novel method was successfully applied to study the kinetics of phenacetin-O deethylation, coumarin-7 hydroxylation, bupropion hydroxylation, taxol-6 hydroxylation, omeprazole-5 hydroxylation, dextromethorphan-O demethylation, tolbutamide-4 hydroxylation, chlorzoxazone-6 hydroxylation, testosterone-6β hydroxylation, and midazolam-1 hydroxylation in rat liver microsomes. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Therapeutic role of niacin in the prevention and regression of hepatic steatosis in rat model of nonalcoholic fatty liver disease.

Science.gov (United States)

Ganji, Shobha H; Kukes, Gary D; Lambrecht, Nils; Kashyap, Moti L; Kamanna, Vaijinath S

2014-02-15

Nonalcoholic fatty liver disease (NAFLD), a leading cause of liver damage, comprises a spectrum of liver abnormalities including the early fat deposition in the liver (hepatic steatosis) and advanced nonalcoholic steatohepatitis. Niacin decreases plasma triglycerides, but its effect on hepatic steatosis is elusive. To examine the effect of niacin on steatosis, rats were fed either a rodent normal chow, chow containing high fat (HF), or HF containing 0.5% or 1.0% niacin in the diet for 4 wk. For regression studies, rats were first fed the HF diet for 6 wk to induce hepatic steatosis and were then treated with niacin (0.5% in the diet) while on the HF diet for 6 wk. The findings indicated that inclusion of niacin at 0.5% and 1.0% doses in the HF diet significantly decreased liver fat content, liver weight, hepatic oxidative products, and prevented hepatic steatosis. Niacin treatment to rats with preexisting hepatic steatosis induced by the HF diet significantly regressed steatosis. Niacin had no effect on the mRNA expression of fatty acid synthesis or oxidation genes (including sterol-regulatory element-binding protein 1, acetyl-CoA carboxylase 1, fatty acid synthase, and carnitine palmitoyltransferase 1) but significantly inhibited mRNA levels, protein expression, and activity of diacylglycerol acyltrasferase 2, a key enzyme in triglyceride synthesis. These novel findings suggest that niacin effectively prevents and causes the regression of experimental hepatic steatosis. Approved niacin formulation(s) for other indications or niacin analogs may offer a very cost-effective opportunity for the clinical development of niacin for treating NAFLD and fatty liver disease.

RATE AND CAPACITY OF HEPATIC MICROSOMAL RING HYDROXYLATION OF PHENOL TO HYDROQUINONE AND CATECHOL IN RAINBOW TROUT (ONCORHYNCHUS MYKISS)

Science.gov (United States)

Rainbow trout liver microsomes were used to study the rate of ring-hydroxylation of phenol (PH) by directly measuring the production of hydroquinone (HQ), the primary metabolite, and catechol (CAT), a secondary metabolite. An HPLC method with integrated ultroviolet (UV) and elect...

Determination of the 4-monohydroxy metabolites of perhexiline in human plasma, urine and liver microsomes by liquid chromatography.

Science.gov (United States)

Davies, Benjamin J; Herbert, Megan K; Coller, Janet K; Somogyi, Andrew A; Milne, Robert W; Sallustio, Benedetta C

2006-11-07

The use of perhexiline (PHX) is limited by hepatic and neurological toxicity associated with elevated concentrations in plasma that are the result of polymorphism of the cytochrome P450 2D6 isoform (CYP2D6). PHX is cleared by hepatic oxidation that produces three 4-monohydroxy metabolites: cis-OH-PHX, trans1-OH-PHX and trans2-OH-PHX. The current study describes an HPLC-fluorescent method utilising pre-column derivatization with dansyl chloride. Following derivatization, the metabolites were resolved on a C18 column with a gradient elution using a mobile phase composed of methanol and water. The method described is suitable for the quantification of the metabolites in human plasma and urine following clinical doses and for kinetic studies using human liver microsomes. The method demonstrates sufficient sensitivity, accuracy and precision between 5.0 and 0.01, 50.0 and 0.2 and 1.0 and 0.005 mg/l in human plasma, urine and liver microsomes, respectively, with intra-assay coefficients of variation and bias D6 extensive metaboliser (EM) patients at steady state with respect to PHX dosing determined that the mean (+/-S.D.) renal clearances of trans1-OH-PHX and cis-OH-PHX were 1.58+/-0.35 and 0.16+/-0.06l/h, respectively. The mean (+/-S.D.) dose recovered in urine as free and glucuronidated 4-monohydroxy PHX metabolites was 20.6+/-11.6%.

Clofibrate improves glucose tolerance in fat-fed rats but decreases hepatic glucose consumption capacity

NARCIS (Netherlands)

Gustafson, LA; Kuipers, F; Wiegman, C; Sauerwein, HP; Romijn, JA; Meijer, AJ

2002-01-01

Background/Aims: High-fat (HF) diets cause glucose intolerance. Fibrates improve glucose tolerance. We have tried to obtain information on possible hepatic mechanisms contributing to this effect. Methods: Rats were fed a HF diet, isocaloric with the control diet, for 3 weeks without or with

Soy compared with milk protein in a western diet changes fecal microbiota and decreases hepatic steatosis in obese OLETF rats

Science.gov (United States)

Soy protein is effective at preventing hepatic steatosis; however, the mechanisms are poorly understood. We tested the hypothesis that soy versus dairy protein-based diet would alter microbiota and attenuate hepatic steatosis in hyperphagic Otsuka Long-Evans Tokushima Fatty (OLETF) rats. Male OLETF ...

Suppression of cytochrome P450 reductase (POR) expression in hepatoma cells replicates the hepatic lipidosis observed in hepatic POR-null mice.

Science.gov (United States)

Porter, Todd D; Banerjee, Subhashis; Stolarczyk, Elzbieta I; Zou, Ling

2011-06-01

Cytochrome P450 reductase (POR) is a microsomal electron transport protein essential to cytochrome P450-mediated drug metabolism and sterol and bile acid synthesis. The conditional deletion of hepatic POR gene expression in mice results in a marked decrease in plasma cholesterol levels counterbalanced by the accumulation of triglycerides in lipid droplets in hepatocytes. To evaluate the role of cholesterol and bile acid synthesis in this hepatic lipidosis, as well as the possible role of lipid transport from peripheral tissues, we developed a stable, small interfering RNA (siRNA)-mediated cell culture model for the suppression of POR. POR mRNA and protein expression were decreased by greater than 50% in McArdle-RH7777 rat hepatoma cells 10 days after transfection with a POR-siRNA expression plasmid, and POR expression was nearly completely extinguished by day 20. Immunofluorescent analysis revealed a marked accumulation of lipid droplets in cells by day 15, accompanied by a nearly 2-fold increase in cellular triglyceride content, replicating the lipidosis seen in hepatic POR-null mouse liver. In contrast, suppression of CYP51A1 (lanosterol demethylase) did not result in lipid accumulation, indicating that loss of cholesterol synthesis is not the basis for this lipidosis. Indeed, addition of cholesterol to the medium appeared to augment the lipidosis in POR-suppressed cells, whereas removal of lipids from the medium reversed the lipidosis. Oxysterols did not accumulate in POR-suppressed cells, discounting a role for liver X receptor in stimulating triglyceride synthesis, but addition of chenodeoxycholate significantly repressed lipid accumulation, suggesting that the absence of bile acids and loss of farnesoid X receptor stimulation lead to excessive triglyceride synthesis.

Clofibric acid increases the formation of oleic acid in endoplasmic reticulum of the liver of rats.

Science.gov (United States)

Hirose, Akihiko; Yamazaki, Tohru; Sakamoto, Takeshi; Sunaga, Katsuyoshi; Tsuda, Tadashi; Mitsumoto, Atsushi; Kudo, Naomi; Kawashima, Yoichi

2011-01-01

The effects of 2-(4-chlorophenoxy)-2-methylpropionic acid (clofibric acid) on the formation of oleic acid (18:1) from stearic acid (18:0) and utilization of the 18:1 formed for phosphatidylcholine (PC) formation in endoplasmic reticulum in the liver of rats were studied in vivo. [¹⁴C]18:0 was intravenously injected into control Wistar male rats and rats that had been fed on a diet containing 0.5% (w/w) clofibric acid for 7 days; and the distribution of radiolabeled fatty acids among subcellular organelles, microsomes, peroxisomes, and mitochondria, was estimated on the basis of correction utilizing the yields from homogenates of marker enzymes for these organelles. The radioactivity was mostly localized in microsomes and the radiolabeled fatty acids present in microsomes were significantly increased by the treatment of rats with clofibric acid. The formation of radiolabeled 18:1 in microsomes markedly increased and incorporations of the formed [¹⁴C]18:1 into PC and phosphatidylethanolamine in microsomes were augmented in response to clofibric acid. The [¹⁴C]18:1 incorporated into PC was mostly located at the C-2 position, but not the C-1 position, of PC, and the radioactivity in 18:1 at the C-2 position of PC was strikingly increased by clofibric acid. These results obtained from the in vivo experiments directly link the findings that clofibric acid treatment induces microsomal stearoyl-CoA desaturase and 1-acylglycerophosphocholine acyltransferase in the liver and the findings that the treatment with the drug elevated absolute mass and mass proportion of 18:1 at the C-2 position, but not the C-1 position, of PC in the liver together.

Ionone Derivatives from the Mycelium of Phellinus linteus and the Inhibitory Effect on Activated Rat Hepatic Stellate Cells

Directory of Open Access Journals (Sweden)

Shiow-Chyn Huang

2016-05-01

Full Text Available Three new γ-ionylideneacetic acid derivatives, phellinulins A–C (1–3, were characterized from the mycelium extract of Phellinus linteus. The chemical structures were established based on the spectroscopic analysis. In addition, phellinulin A (1 was subjected to the examination of effects on activated rat hepatic stellate cells and exhibited significant inhibition of hepatic fibrosis.

Low prevalence of liver-kidney microsomal autoantibodies of type 1 (LKM1) in hepatitis C seropositive subjects on Crete, Greece.

Science.gov (United States)

Drygiannakis, D; Lionis, C; Drygiannakis, I; Pappas, G; Kouroumalis, E

2001-01-01

Hepatitis C is a serious problem on the Greek island of Crete, where a high prevalence of antibodies against hepatitis C (anti-HCV) has recently been reported. This article reports the findings of a study carried out in Crete, which investigated the prevalence of serum autoantibodies in patients with chronic hepatitis C. One hundred and forty two patients (59 men and 83 women), who were found anti-HCV seropositive in two hospitals and two Primary Health Care Centres in Crete, were eligible. Sixty healthy blood donors (46 men, 14 women), which were negative to anti-HCV, were used as the control group. They were randomly selected from those attending Rethymnon Hospital. Autoantibodies were identified using the indirect immunofluorescence (IFL) technique on human epithelial cells from larynx cancer (HEp-2 cells), rat liver-kidney-stomach substrate (CT3) and Chrithidia Luciliae (CL). Serum autoantibodies were detected in 104 HCV patients, yielding an overall prevalence of 73.2%. The most frequent autoantibodies were antinuclear antibodies (ANA), positive in 72 patients (50.7%). Anti-smooth muscle antibodies (ASMA) were detected in 33 patients (23.2%). Only one patient was positive for LKM1 autoantibodies. No autoantibodies were found in 38 patients (26.7%). Autoantibodies were also found in 5 out of the 60 examined healthy blood donors (8.3%). Autoantibodies, mainly ANA and ASMA are very common in HCV seropositive patients from Crete. By contrast LKM1 autoantibodies are exceptionally rare in these patients.

The effect of down-regulation of Smad3 by RNAi on hepatic stellate cells and a carbon tetrachloride-induced rat model of hepatic fibrosis

Directory of Open Access Journals (Sweden)

Z.R. Wang

2011-02-01

Full Text Available Searching for effective Smad3 gene-based gene therapies for hepatic fibrosis, we constructed siRNA expression plasmids targeting the rat Smad3 gene and then delivered these plasmids into hepatic stellate cells (HSCs. The effect of siRNAs on the mRNA levels of Smad2, Smad3, Smad4, and collagens I-α1, III-α1 and IV-α1 (Colα1, Col3α1, Col4α1, respectively was determined by RT-PCR. Eighty adult male Sprague-Dawley rats were randomly divided into three groups. Twice a week for 8 weeks, the untreated hepatic fibrosis model (N = 30 and the treated group (N = 20 were injected subcutaneously with 40% (v/v carbon tetrachloride (CCl4-olive oil (3 mL/kg, and the normal control group (N = 30 was injected with olive oil (3 mL/kg. In the 4th week, the treated rats were injected subcutaneously with liposome-encapsulated plasmids (150 µg/kg into the right liver lobe under general anesthesia once every 2 weeks, and the untreated rats were injected with the same volume of buffer. At the end of the 6th and 8th weeks, liver tissue and sera were collected. Pathological changes were assessed by a semi-quantitative scoring system (SSS, and a radioimmunoassay was used to establish a serum liver fibrosis index (type III procollagen, type IV collagen, laminin, and hyaluronic acid. The mRNA expression levels of the above cited genes were reduced in the HSCs transfected with the siRNA expression plasmids. Moreover, in the treated group, fibrosis evaluated by the SSS was significantly reduced (P < 0.05 and the serum indices were greatly improved (P < 0.01. These results suggest that Smad3 siRNA expression plasmids have an anti-fibrotic effect.

Differential Effects of Three Techniques for Hepatic Vascular Exclusion during Resection for Liver Cirrhosis on Hepatic Ischemia-Reperfusion Injury in Rats

Directory of Open Access Journals (Sweden)

Changjun Jia

2018-01-01

Full Text Available Background/Aims. Hepatic ischemia-reperfusion (I/R injury is a serious concern during hepatic vascular occlusion. The objectives of this study were to assess effects of three techniques for hepatic vascular occlusion on I/R injury and to explore the underlying mechanisms. Methods. Liver cirrhotic rats had undertaken Pringle maneuver (PR, hemihepatic vascular occlusion (HH, or hepatic blood inflow occlusion without hemihepatic artery control (WH. Levels of tumor necrosis factor alpha (TNF-α, nuclear factor kappa B (NF-κB, toll-like receptor 4 (TLR4, TIR-domain-containing adapter-inducing interferon-β (TRIF, and hemeoxygenase 1 (HMOX1 were assayed. Results. The histopathologic analysis displayed that liver harm was more prominent in the PR group, but similar in the HH and WH groups. The HH and WH groups responded to hepatic I/R inflammation similarly but better than the PR group. Mechanical studies suggested that TNF-α/NF-κB signaling and TLR4/TRIF transduction pathways were associated with the differential effects. In addition, the HH and WH groups had significantly higher levels of hepatic HMOX1 (P<0.05 than the PR group. Conclusions. HH and WH confer better preservation of liver function and protection than the Pringle maneuver in combating I/R injury. Upregulation of HMOX1 may lead to better protection and clinical outcomes after liver resection.

Diagnosis and therapy of autoimmune hepatitis.

Science.gov (United States)

Granito, Alessandro; Muratori, Paolo; Ferri, Silvia; Pappas, Georgios; Quarneti, Chiara; Lenzi, Marco; Bianchi, Francesco B; Muratori, Luigi

2009-06-01

Autoimmune hepatitis (AIH) is a chronic progressive hepatitis, characterized by interface hepatitis with lymphoplasmacellular infiltrates on liver biopsy, high serum globulin level and circulating autoantibodies. It is classified into two types, according to autoantibody profile: type 1 is characterized by anti-nuclear (ANA) and/or anti-smooth muscle (SMA) antibodies; type 2 by anti-liver kidney microsomal type 1 (anti-LKM-1) antibodies. AIH affects all ages, may be asymptomatic, frequently has an acute onset, and can present as fulminant hepatitis. The diagnosis of AIH is based on a scoring system codified by an international consensus. Corticosteroids alone or in conjunction with azathioprine is the treatment of choice in patients with AIH and results in remission induction in over 80% of patients. Alternative proposed strategies in patients who have failed to achieve remission on standard therapy or patients with drug toxicity include the use of cyclosporine, tacrolimus, budesonide or mycophenolate mofetil. Liver transplantation is the treatment of choice in managing decompensated disease, however AIH can recur or develop de novo after liver transplantation.

BKR 27(1) pp. 50-55 (Achuba et al)

African Journals Online (AJOL)

Femi J. Olorunniji

2015-03-31

Mar 31, 2015 ... Biokemistri 27(1): 50–55. 54. Farombi, E.O. (2000) Mechanisms for the hepatoprotective action of kolaviron, studies on hepatic enzymes, microsomal lipids and peroxidation in carbon tetrachloride-treated rats. Pharmacological Research 42: 75–80. Farris MW (1991) Cadmium toxicity: Unique cytoprotective.

Effects of Arctium lappa aqueous extract on lipid profile and hepatic enzyme levels of sucrose-induced metabolic syndrome in female rats

Directory of Open Access Journals (Sweden)

Akram Ahangarpour

Full Text Available ABSTRACT Arctium lappa is known to have antioxidant and antidiabetic effects in traditional medicine. Objectives: The aim of this paper was to study the effects of A. lappa root extract (AE on lipid profile and hepatic enzyme levels in sucrose-induced metabolic syndrome (MS in female rats. The study used 40 adult female Wistar rats weighing 150 g-250 g randomly divided into five groups: control, metabolic syndrome (MS, metabolic syndrome+AE at 50,100, 200 mg/kg. MS was induced by administering 50% sucrose in drinking water for 6 weeks. AE was intra-peritoneally administered daily at doses of 50,100, and 200 mg/kg for two sequential weeks at the end of the fourth week in metabolic syndrome rats. Twenty-four hours after the last administration of AE, blood was collected and centrifuged, and then the serum was used for the measurement of lipid profile and hepatic enzyme. Serum glucose, insulin, fasting insulin resistance index, body weight, water intake, lipid profile, and hepatic enzymes were significantly increased although food intake was decreased in MS rats compared to the control rats. The lipids and liver enzymes were reduced by AE extracts in the MS group. This study showed that the A. lappa root aqueous extract exhibits a hypolipidemic activity of hyperlipidemic rats. This activity is practically that of a triple-impact antioxidant, hypolipidemic, and hepatoprotective.

Increased binding of LDL and VLDL to apo B,E receptors of hepatic plasma membrane of rats treated with Fibernat.

Science.gov (United States)

Venkatesan, Nandini; Devaraj, S Niranjali; Devaraj, H

2003-10-01

Research has focussed on the hypocholesterolemic effects of certain types of dietary fiber such as enhancing conversion of hepatic cholesterol to bile acids or increase in catabolism of low density lipoprotein (LDL) via the apo B,E receptor. The effect of oral administration of a unique fibre cocktail of fenugreek seed powder, guar gum and wheat bran (Fibernat) and its varied effects on some aspects of lipid metabolism and cholesterol homeostasis in rats were examined. Rats were administered Fibernat along with the atherogenic diet containing 1.5 % cholesterol and 0.1 % cholic acid. Amounts of hepatic lipids, hepatic and fecal bile acids and activity of hepatic triglyceride lipase (HTGL) were determined. Transmission electron microscopic examination of the liver tissue and extent of uptake of (125)I-LDL and (125)I-VLDL by the hepatic apo B,E receptor was carried out. Food intake and body weight gain were similar between the 3 different dietary groups. Fibernat intake significantly increased apo B,E receptor expression in rat liver as reflected by an increase in the maximum binding capacity (B(max)) of the apo B,E receptor to (125)I-LDL and (125)I-VLDL. The activity of HTGL was increased by approximately 1.5-fold in Fibernat-fed rats as compared to those fed the atherogenic diet alone. A marked hypocholesterolemic effect was observed. Cholesterol homeostasis was achieved in Fibernat-fed rats. Two possible mechanisms are postulated to be responsible for the observed hypocholesterolemic effect a) an increase in conversion of cholesterol to bile acids and b) possibly by intra-luminal binding which resulted in increased fecal excretion of bile acids and neutral sterols. The resulting reduction in cholesterol content of liver cells coupled with upregulation of hepatic apo B,E receptors and increased clearance of circulating atherogenic lipoproteins-LDL and very low density lipoprotein (LDL and VLDL)-is the main mechanism involved in the hypocholesterolemic effect of

Comparison of TCDD-elicited genome-wide hepatic gene expression in Sprague–Dawley rats and C57BL/6 mice

Energy Technology Data Exchange (ETDEWEB)

Nault, Rance; Kim, Suntae; Zacharewski, Timothy R., E-mail: tzachare@msu.edu

2013-03-01

Although the structure and function of the AhR are conserved, emerging evidence suggests that downstream effects are species-specific. In this study, rat hepatic gene expression data from the DrugMatrix database (National Toxicology Program) were compared to mouse hepatic whole-genome gene expression data following treatment with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). For the DrugMatrix study, male Sprague–Dawley rats were gavaged daily with 20 μg/kg TCDD for 1, 3 and 5 days, while female C57BL/6 ovariectomized mice were examined 1, 3 and 7 days after a single oral gavage of 30 μg/kg TCDD. A total of 649 rat and 1386 mouse genes (|fold change| ≥ 1.5, P1(t) ≥ 0.99) were differentially expressed following treatment. HomoloGene identified 11,708 orthologs represented across the rat Affymetrix 230 2.0 GeneChip (12,310 total orthologs), and the mouse 4 × 44K v.1 Agilent oligonucleotide array (17,578 total orthologs). Comparative analysis found 563 and 922 orthologs differentially expressed in response to TCDD in the rat and mouse, respectively, with 70 responses associated with immune function and lipid metabolism in common to both. Moreover, QRTPCR analysis of Ceacam1, showed divergent expression (induced in rat; repressed in mouse) functionally consistent with TCDD-elicited hepatic steatosis in the mouse but not the rat. Functional analysis identified orthologs involved in nucleotide binding and acetyltransferase activity in rat, while mouse-specific responses were associated with steroid, phospholipid, fatty acid, and carbohydrate metabolism. These results provide further evidence that TCDD elicits species-specific regulation of distinct gene networks, and outlines considerations for future comparisons of publicly available microarray datasets. - Highlights: ► We performed a whole-genome comparison of TCDD-regulated genes in mice and rats. ► Previous species comparisons were extended using data from the DrugMatrix database. ► Less than 15% of TCDD

Solanum nigrum Protects against Hepatic Fibrosis via Suppression of Hyperglycemia in High-Fat/Ethanol Diet-Induced Rats

Directory of Open Access Journals (Sweden)

Cheng-Jeng Tai

2016-02-01

Full Text Available Background: Advanced glycation end products (AGEs signal through the receptor for AGE (RAGE, which can lead to hepatic fibrosis in hyperglycemia and hyperlipidemia. We investigated the inhibitory effect of aqueous extracts from Solanum nigrum (AESN on AGEs-induced RAGE signaling and activation of hepatic stellate cells (HSCs and hyperglycemia induced by high-fat diet with ethanol. Methods: An animal model was used to evaluate the anti-hepatic fibrosis activity of AESN in rats fed a high-fat diet (HFD; 30% with ethanol (10%. Male Wistar rats (4 weeks of age were randomly divided into four groups (n = 6: (1 control (basal diet; (2 HFD (30% + ethanol (10% (HFD/ethanol; (3 HFD/ethanol + AESN (100 mg/kg, oral administration; and (4 HFD/ethanol + pioglitazone (10 mg/kg, oral administration and treated with HFD for 6 months in the presence or absence of 10% ethanol in dietary water. Results: We found that AESN improved insulin resistance and hyperinsulinemia, and downregulated lipogenesis via regulation of the peroxisome proliferator-activated receptor α (PPARα, PPARγ co-activator (PGC-1α, carbohydrate response element-binding protein (ChREBP, acetyl-CoA carboxylase (ACC, and fatty acid synthase (FAS mRNA levels in the liver of HFD/ethanol-treated rats. In turn, AESN may delay and inhibit the progression of hepatic fibrosis, including α-smooth muscle actin (α-SMA inhibition and MMP-2 production. Conclusions: These results suggest that AESN may be further explored as a novel anti-fibrotic strategy for the prevention of liver disease.

Influence of frequently used industrial solvents and monomers of plastics on xenobiotic metabolism

Energy Technology Data Exchange (ETDEWEB)

Gut, I. (Institut Hygieny a Epidemiologie, Prague (Czechoslovakia))

1983-11-01

In male Wistar rats, inhalation of benzene, toluene, or styrene induced a dose-dependent increase of the in vitro hepatic microsomal metabolism of benzene, but toluene metabolism and microsomal cytochrome P-450 level were little affected. In phenobarbital pretreated rats the solvents induced increased biotransformation of benzene metabolism toluene, but relatively less than in controls, and benzene and toluene inhalation actually caused an apparent destruction of cytochrome P-450. In vivo rates of metabolism of toluene and styrene were in good agreement with the in vitro hepatic microsomal biotransformation of benzene or toluene, but benzene metabolism not due to inhibition of benzene metabolism in vivo caused by benzene metabolites. In simultaneously administered two solvents, toluene, styrene or xylene markedly inhibited metabolism of benzene-/sup 14/C, but toluene-/sup 14/C metabolsim was little affected by coadministered benzene, styrene or xylene. Various industrial solvents inhibited metabolism of acrylonitrile along the oxidative pathway leading to thiocyanate, but actually increased the rate of the conjugative pathway beginning with cyanoethylation of glutathion and the final products. Various derivatives of benzene had low inhibiting effect on antipyrine metabolism and clinical significance of such effect is of little significance. Inhibition of benzene metabolism by toluene followed in significantly decreased myelotoxicity of benzene, but the modification of acrylonitrile metabolism and pharmacokinetics by organic solvents given at low doses markedly increased lethal effects of acrylonitrile. The prediction of in vivo rates of metabolism based on the in vitro rates of hepatic microsomal metabolism is therefore possible, provided the inhibiting potency of the xenobiotic and/or its metabolites, self-induction of their metabolism, as well as differences in their pharmacokinetics are considered.

Age dependence of rat liver function measurements

DEFF Research Database (Denmark)

Fischer-Nielsen, A; Poulsen, H E; Hansen, B A

1989-01-01

Changes in the galactose elimination capacity, the capacity of urea-N synthesis and antipyrine clearance were studied in male Wistar rats at the age of 8, 20 and 44 weeks. Further, liver tissue concentrations of microsomal cytochrome P-450, microsomal protein and glutathione were measured. All...... liver function measurements increased from the age of 8 to 44 weeks when expressed in absolute values. In relation to body weight, these function measurements were unchanged or reduced from week 8 to week 20. At week 44, galactose elimination capacity and capacity of urea-N synthesis related to body...... weight were increased by 10% and 36%, respectively, and antipyrine plasma clearance was reduced to 50%. Liver tissue concentrations of microsomal cytochrome P-450 and microsomal protein increased with age when expressed in absolute values, but were unchanged per g liver, i.e., closely related to liver...

Mechanism of action of hypoglycemic effects of an intestine-specific inhibitor of microsomal triglyceride transfer protein (MTP) in obese rats.

Science.gov (United States)

Sakata, Shohei; Katsumi, Sohei; Mera, Yasuko; Kuroki, Yukiharu; Nashida, Reiko; Kakutani, Makoto; Ohta, Takeshi

2015-01-01

Diminished insulin sensitivity in the peripheral tissues and failure of pancreatic beta cells to secrete insulin are known major determinants of type 2 diabetes mellitus. JTT-130, an intestine-specific microsomal transfer protein inhibitor, has been shown to suppress high fat-induced obesity and ameliorate impaired glucose tolerance while enhancing glucagon-like peptide-1 (GLP-1) secretion. We investigated the effects of JTT-130 on glucose metabolism and elucidated the mechanism of action, direct effects on insulin sensitivity and glucose-stimulated insulin secretion in a high fat diet-induced obesity rat model. Male Sprague Dawley rats fed a high-fat diet were treated with a single administration of JTT-130. Glucose tolerance, hyperglycemic clamp and hyperinsulinemic-euglycemic testing were performed to assess effects on insulin sensitivity and glucose-stimulated insulin secretion, respectively. Plasma GLP-1 and tissue triglyceride content were also determined under the same conditions. A single administration of JTT-130 suppressed plasma glucose elevations after oral glucose loading and increased the disposition index while elevating GLP-1. JTT-130 also enhanced glucose-stimulated insulin secretion in hyperglycemic clamp tests, whereas increased insulin sensitivity was observed in hyperinsulinemic-euglycemic clamp tests. Single-dose administration of JTT-130 decreased lipid content in the liver and skeletal muscle. JTT-130 demonstrated acute and direct hypoglycemic effects by enhancing insulin secretion and/or insulin sensitivity. Copyright © 2014 Japanese Pharmacological Society. Production and hosting by Elsevier B.V. All rights reserved.

The enhanced atorvastatin hepatotoxicity in diabetic rats was partly attributed to the upregulated hepatic Cyp3a and SLCO1B1

Science.gov (United States)

Shu, Nan; Hu, Mengyue; Ling, Zhaoli; Liu, Peihua; Wang, Fan; Xu, Ping; Zhong, Zeyu; Sun, Binbin; Zhang, Mian; Li, Feng; Xie, Qiushi; Liu, Xiaodong; Liu, Li

2016-01-01

Liver injury is a common adverse effect of atorvastatin. This study aimed to investigate atorvastatin-induced hepatotoxicity in diabetic rats induced by high-fat diet combined with streptozotocin. The results showed that 40 mg/kg atorvastatin was lethal to diabetic rats, whose mean survival time was 6.2 days. Severe liver injury also occurred in diabetic rats treated with 10 mg/kg and 20 mg/kg atorvastatin. The in vitro results indicated that atorvastatin cytotoxicity in hepatocytes of diabetic rats was more severe than normal and high-fat diet feeding rats. Expressions and activities of hepatic Cyp3a and SLCO1B1 were increased in diabetic rats, which were highly correlated with hepatotoxicity. Antioxidants (glutathione and N-Acetylcysteine), Cyp3a inhibitor ketoconazole and SLCO1B1 inhibitor gemfibrozil suppressed cytotoxicity and ROS formation in primary hepatocytes of diabetic rats. In HepG2 cells, up-regulations of CYP3A4 and SLCO1B1 potentiated hepatotoxicity and ROS generation, whereas knockdowns of CYP3A4 and SLCO1B1 as well as CYP3A4/SLCO1B1 inhibitions showed the opposite effects. Phenobarbital pretreatment was used to induce hepatic Cyp3a and SLCO1B1 in rats. Phenobarbital aggravated atorvastatin-induced hepatotoxicity, while decreased plasma exposure of atorvastatin. All these findings demonstrated that the upregulations of hepatic Cyp3a and SLCO1B1 in diabetic rats potentiated atorvastatin-induced hepatotoxicity via increasing ROS formation. PMID:27624558

Decreased duration of pentobarbital-induced narcosis in immature and adult female rats prenatally exposed to cimetidine

International Nuclear Information System (INIS)

Donnelly, D.A.; Iba, M.M.

1986-01-01

The effect of prenatal cimetidine exposure (PreCM) on the duration of pentobarbital-induced narcosis (DPN) was assessed in immature (14- and 28-day old) and adult (50-60-day old) male and female rats. PreCM exposure was accomplished by treating mothers with cimetidine (CM) (20 mg/kg, ip) daily for the last two days of gestation and then (0.01% in drinking water) throughout lactation. Pregnant mothers of untreated offspring (Con) received saline. PreCM decreased DPN to 505 +/- 33 min (from 611 +/- 23 min in Con) and 393 +/- 190 min (from 686 +/- 44 min in Con) in 14-day old male and female rats, respectively. Similarly, PreCM decreased DPN to 88 +/- 15 min (from 134 +/- 3 min in Con) and 102 +/- 19 min (from 171 +/- 44 min in Con) in 28-day old male and female rats, respectively. At 21 days, PreCM did not alter DPN in either sex. At 50-60 days, however, it decreased DPN to 144 +/- 41 min (from 238 +/- 7 min in Con) in females but had no effect in males; PreCM also increased the plasma clearance of administered 14 C-pentobarbital more in females than in males. The effects of PreCM, particularly the long-term effects, were most prominent in female rats and were the opposite of those of postnatal treatment with CM. The results together with those of studies with hepatic microsomes suggest that PreCM may have resulted in the induction of hepatic drug-metabolizing enzymes during the perinatal period

Environmentally relevant organophosphate triesters in herring gulls: In vitro biotransformation and kinetics and diester metabolite formation using a hepatic microsomal assay

International Nuclear Information System (INIS)

Greaves, Alana K.; Su, Guanyong; Letcher, Robert J.

2016-01-01

The in vitro biotransformation and kinetics of six organophosphate triester (OPE) flame retardants were investigated in herring gulls (Larus argentatus) from the Great Lakes using a hepatic microsomal metabolism assay. Administration of each individual OPE (tri-n-butyl phosphate (TNBP), tris(2-butoxyethyl) phosphate (TBOEP), triphenyl phosphate (TPHP), triethyl phosphate (TEP), tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) and tris(2-chloroisopropyl) phosphate (TCIPP)) to the in vitro assay (concentration range 0.01 to 10 μM) resulted in rapid depletion with the exception of TEP. Following the Michaelis-Menten enzyme kinetics model, a preliminary 2-minute incubation period was used to estimate the V max (± SE) values (i.e., the maximal rate of reaction for a saturated enzyme system), which ranged from 5.0 ± 0.4 (TPHP) to 29 ± 18 pmol/min/mg protein (TBOEP), as well as the K M (± SE) values (i.e., the OPE concentration corresponding to one half of the V max ), which ranged from 9.8 ± 1 (TPHP) to 189 ± 135 nM (TBOEP). Biotransformation assays over a 100-minute incubation period revealed that TNBP was metabolized most rapidly (with a depletion rate of 73 ± 4 pmol/min/mg protein), followed by TBOEP (53 ± 8 pmol/min/mg), TCIPP (27 ± 1 pmol/min/mg), TPHP (22 ± 2 pmol/min/mg) and TDCIPP (8 ± 1 pmol/min/mg). In vitro biotransformation of OP triesters was clearly structure-dependent where non-halogenated alkyl OP triesters were metabolized more rapidly than halogenated alkyl triesters. Halogenated OP triesters were transformed to their respective diesters more efficiently relative to non-halogenated OP triesters. To our knowledge, this is the first study to investigate OP triester metabolism and OP diester formation in an avian or wildlife model system, which is important to understand the fate and biological activity of OPEs in an exposed organism. - Highlights: • The metabolism and kinetics of 6 OPEs were examined in herring gull liver microsomes. • The

Environmentally relevant organophosphate triesters in herring gulls: In vitro biotransformation and kinetics and diester metabolite formation using a hepatic microsomal assay

Energy Technology Data Exchange (ETDEWEB)

Greaves, Alana K. [Wildlife and Landscape Directorate, Science and Technology Branch, Environment and Climate Change Canada, National Wildlife Research Centre, Carleton University, Ottawa, ON K1A 0H3 (Canada); Department of Chemistry, Carleton University, Ottawa, ON K1S 5B6 (Canada); Su, Guanyong, E-mail: guanyong.su85@gmail.com [Wildlife and Landscape Directorate, Science and Technology Branch, Environment and Climate Change Canada, National Wildlife Research Centre, Carleton University, Ottawa, ON K1A 0H3 (Canada); Department of Chemistry, Carleton University, Ottawa, ON K1S 5B6 (Canada); Letcher, Robert J., E-mail: robert.letcher@canada.ca [Wildlife and Landscape Directorate, Science and Technology Branch, Environment and Climate Change Canada, National Wildlife Research Centre, Carleton University, Ottawa, ON K1A 0H3 (Canada); Department of Chemistry, Carleton University, Ottawa, ON K1S 5B6 (Canada)

2016-10-01

The in vitro biotransformation and kinetics of six organophosphate triester (OPE) flame retardants were investigated in herring gulls (Larus argentatus) from the Great Lakes using a hepatic microsomal metabolism assay. Administration of each individual OPE (tri-n-butyl phosphate (TNBP), tris(2-butoxyethyl) phosphate (TBOEP), triphenyl phosphate (TPHP), triethyl phosphate (TEP), tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) and tris(2-chloroisopropyl) phosphate (TCIPP)) to the in vitro assay (concentration range 0.01 to 10 μM) resulted in rapid depletion with the exception of TEP. Following the Michaelis-Menten enzyme kinetics model, a preliminary 2-minute incubation period was used to estimate the V{sub max} (± SE) values (i.e., the maximal rate of reaction for a saturated enzyme system), which ranged from 5.0 ± 0.4 (TPHP) to 29 ± 18 pmol/min/mg protein (TBOEP), as well as the K{sub M} (± SE) values (i.e., the OPE concentration corresponding to one half of the V{sub max}), which ranged from 9.8 ± 1 (TPHP) to 189 ± 135 nM (TBOEP). Biotransformation assays over a 100-minute incubation period revealed that TNBP was metabolized most rapidly (with a depletion rate of 73 ± 4 pmol/min/mg protein), followed by TBOEP (53 ± 8 pmol/min/mg), TCIPP (27 ± 1 pmol/min/mg), TPHP (22 ± 2 pmol/min/mg) and TDCIPP (8 ± 1 pmol/min/mg). In vitro biotransformation of OP triesters was clearly structure-dependent where non-halogenated alkyl OP triesters were metabolized more rapidly than halogenated alkyl triesters. Halogenated OP triesters were transformed to their respective diesters more efficiently relative to non-halogenated OP triesters. To our knowledge, this is the first study to investigate OP triester metabolism and OP diester formation in an avian or wildlife model system, which is important to understand the fate and biological activity of OPEs in an exposed organism. - Highlights: • The metabolism and kinetics of 6 OPEs were examined in herring gull liver

Effects of dietary inulin, statin, and their co-treatment on hyperlipidemia, hepatic steatosis and changes in drug-metabolizing enzymes in rats fed a high-fat and high-sucrose diet

Directory of Open Access Journals (Sweden)

Sugatani Junko

2012-03-01

Full Text Available Abstract Background Rats fed a high-fat and high-sucrose (HF diet develop hepatic steatosis and hyperlipidemia. There are several reports that a change in nutritional status affects hepatic levels of drug-metabolizing enzymes. Synthetic inulin is a dietary component that completely evades glucide digestion. Supplementing a HF diet with inulin ameliorates hypertriglycemia and hepatic steatosis, but not hypercholesterolemia. This study aimed at distinguishing the effects of synthetic inulin and 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor (statin, which inhibit cholesterol biosynthesis. Methods We examined effects of co-treatment with synthetic inulin (5% and fluvastatin (0, 4, and 8 mg/kg, per os on body weight, epidydimal white adipose tissue weight, serum and hepatic lipid profiles, and hepatic cytochrome P450 (CYP mRNA and protein profiles in rats fed a standard diet or a HF diet for 3 weeks. Results Treatment with the synthetic inulin (5% or fluvastatin at 4 mg/kg (lethal dose in rats fed the HF diet, 8 mg/kg ameliorated the elevation in hepatic triacylglycerol and total cholesterol levels in rats fed the HF diet. Whereas co-treatment with the inulin (5% and fluvastatin (4 mg/kg had a tendency to more strongly suppress the elevation in serum levels of very low density lipoprotein triacylglycerol than either treatment alone, no additive or synergistic effect was found in decrease in hepatic lipid levels. Hepatic levels of CYP1A1/2 and CYP2E1 mRNA and protein and methoxyresorufin O-demethylase and ethoxyresorufin O-deethylase activities were reduced in rats fed the HF diet. The synthetic inulin alleviated the reduction in hepatic levels of CYP1A1/2 and CYP2E1 mRNA and protein more strongly than fluvastatin, and no synergistic effects were observed on co-treatment. Furthermore, hepatic levels of aryl hydrocarbon receptor mRNA were decreased in rats fed the HF diet and recovered to near normal values with the intake of dietary inulin

Effect of treatment with cadmium on kinetic properties of Na+, K+-ATPase and glucose-6-phosphatase activity in rat liver microsomes

International Nuclear Information System (INIS)

Modi, Hiren R.; Patil, Nisha; Katyare, Surendra S.

2008-01-01

Studies on Cd hepatotoxicity have focused mainly on induction of cytochrome P 450 system and related enzymes. In the present study young adult male rats given a single intra-peritoneal injection of Cd (0.84 mg Cd/kg body weight) and effects on kinetic parameters rat liver microsomal Na + , K + -ATPase and G6Pase were evaluated at the end of 1 month and 1 week. The substrate and temperature kinetics parameters were examined and attempts were made to seek correlation with changes in lipid/phospholipid profiles. The Na + , K + ATPase activity decreased only in 1 week Cd-treated group but recovered at the end of 1 month. The activity resolved in two distinct kinetic components in control as well as the experimental groups. In 1 week Cd-treated group the K m value of both the components was unchanged, whereas V max value decreased. In 1-month Cd-treated group V max value only of component I increased. The catalytic efficiency of both the components was not affected in the experimental groups. In 1-week Cd-treated group the energy of activations at high-temperature range (E H ) and low-temperature range (E L ) decreased, whereas for 1-month Cd-treated group the energies of activations did not change. The G6Pase activity measured at 37 deg. C was high only in 1-month Cd-treated group. The activity resolved in two kinetically distinguishable components in control as well as in the experimental groups. K m value of component I decreased in both the Cd-treated groups. In 1-month Cd-treated group the V max value of component II increased. The catalytic efficiency of G6Pase was unchanged despite changes in K m and V max . In 1-week Cd-treated group the E H and E L decreased, whereas only E L showed decrease in 1-month Cd-treated group. Cholesterol (CHL) content increased in both the Cd-treated groups. Content of lysophospholipid (Lyso), spinghomyelin (SPM) and phosphatidic acid (PA) increased, whereas phosphatidylcholine (PC) and phosphatidylserine (PS) decreased in 1-week Cd

Central effects of humanin on hepatic triglyceride secretion.

Science.gov (United States)

Gong, Zhenwei; Su, Kai; Cui, Lingguang; Tas, Emir; Zhang, Ting; Dong, H Henry; Yakar, Shoshana; Muzumdar, Radhika H

2015-08-01

Humanin (HN) is an endogenous mitochondria-associated peptide that has been shown to protect against various Alzheimer's disease-associated insults, myocardial ischemia-reperfusion injury, and reactive oxygen species-induced cell death. We have shown previously that HN improves whole body glucose homeostasis by improving insulin sensitivity and increasing glucose-stimulated insulin secretion (GSIS) from the β-cells. Here, we report that intraperitoneal treatment with one of HN analogs, HNG, decreases body weight gain, visceral fat, and hepatic triglyceride (TG) accumulation in high-fat diet-fed mice. The decrease in hepatic TG accumulation is due to increased activity of hepatic microsomal triglyceride transfer protein (MTTP) and increased hepatic TG secretion. Both intravenous (iv) and intracerebroventricular (icv) infusion of HNG acutely increase TG secretion from the liver. Vagotomy blocks the effect on both iv and icv HNG on TG secretion, suggesting that the effects of HNG on hepatic TG flux are centrally mediated. Our data suggest that HN is a new player in central regulation of peripheral lipid metabolism. Copyright © 2015 the American Physiological Society.

5-lipoxygenase activation is involved in the mechanisms of chronic hepatic injury in a rat model of chronic aluminum overload exposure

Energy Technology Data Exchange (ETDEWEB)

Mai, Shaoshan [Department of Pharmacology, Chongqing Medical University, Key Laboratory of Biochemistry and Molecular Pharmacology, Chongqing 400016 (China); He, Qin [Department of Heptobiliary Surgery, 1st Affiliated Hospital, Chongqing Medical University, Chongqing 400016 (China); Wang, Hong; Hu, Xinyue; Luo, Ying; Yang, Yang; Kuang, Shengnan; Tian, Xiaoyan; Ma, Jie [Department of Pharmacology, Chongqing Medical University, Key Laboratory of Biochemistry and Molecular Pharmacology, Chongqing 400016 (China); Yang, Junqing, E-mail: 1139627371@qq.com [Department of Pharmacology, Chongqing Medical University, Key Laboratory of Biochemistry and Molecular Pharmacology, Chongqing 400016 (China)

2016-08-15

We previously confirmed that rats overloaded with aluminum exhibited hepatic function damage and increased susceptibility to hepatic inflammation. However, the mechanism of liver toxicity by chronic aluminum overload is poorly understood. In this study, we investigated changes in the 5-lipoxygenase (5-LO) signaling pathway and its effect on liver injury in aluminum-overloaded rats. A rat hepatic injury model of chronic aluminum injury was established via the intragastric administration of aluminum gluconate (Al{sup 3+} 200 mg/kg per day, 5 days a week for 20 weeks). The 5-LO inhibitor, caffeic acid (10 and 30 mg/kg), was intragastrically administered 1 h after aluminum administration. Hematoxylin and eosin staining was used to visualize pathological changes in rat liver tissue. A series of biochemical indicators were measured with biochemistry assay or ELISAs. Immunochemistry and RT-PCR methods were used to detect 5-LO protein and mRNA expression in the liver, respectively. Caffeic acid administration protected livers against histopathological injury, decreased plasma ALT, AST, and ALP levels, decreased TNF-α, IL-6, IL-1β and LTs levels, increased the reactive oxygen species content, and down-regulated the mRNA and protein expressions of 5-LO in aluminum overloaded rats. Our results indicate that 5-lipoxygenase activation is mechanistically involved in chronic hepatic injury in a rat model of chronic aluminum overload exposure and that the 5-LO signaling pathway, which associated with inflammation and oxidative stress, is a potential therapeutic target for chronic non-infection liver diseases. - Highlights: • 5-LO signaling contributes to mechanisms of hepatotoxicity of aluminum overload. • Oxidative and inflammatory reaction involve in chonic aluminum hepatotoxicity. • 5-LO inhibitor has a protective effect on aluminum-overload liver injury. • 5-LO signaling is a potential therapeutic target for non-infection liver diseases.

Isolation and purification of rat liver morphine UDP-glucuronosyltransferase

International Nuclear Information System (INIS)

Puig, J.F.; Tephly, T.R.

1986-01-01

The enhancement of rat liver microsomal morphine (M) and 4-hydroxybiphenyl (4-HBP) UDP-glucuronyltransferase (UDPGT) activities by phenobarbital treatment has been proposed to represent increased activity of a single enzyme form, GT-2. They have separated M and 4-HBP UDPGT activities from Emulgen 911-solubilized microsomes obtained from livers of phenobarbital-treated Wistar rats. A sensitive assay procedure was developed to quantify M-UDPGT and 4-HBP-UDPGT activities using 14 C-UDP-glucuronic acid (UDPGA) and reversed phase C-18 minicolumns whereby the radioactive glucuronides were differentially eluted from labeled UDPGA. Trisacryl DEAE, and chromatofocusing procedures were employed to separate M-UDPGT and 4-HBP-UDPGT in the presence of exogenous phosphatidylcholine (PC). The PC is necessary to stabilize UDPGT activities. M-UDPGT was isolated to apparent homogeneity and displayed a monomeric molecular weight of 56,000 daltons on SDS-PAGE. It reacted with M but not with 4-HBP, bilirubin, p-nitrophenol, testosterone, androsterone, estrone, 4-aminobiphenyl or α-naphthylamine. 4-HBP-UDPGT did not react with M. Therefore, M and 4-HBP glucuronidations are catalyzed by separate enzymes in rat liver microsomes

Inositol trisphosphate and thapsigargin discriminate endoplasmic reticulum stores of calcium in rat brain

DEFF Research Database (Denmark)

Verma, A; Hirsch, D J; Hanley, M R

1990-01-01

ATP dependent Ca2+ accumulation into oxalate-loaded rat brain microsomes is potently inhibited by thapsigargin with an IC50 of 2 nM and maximal inhibition at 10 nM. Approximately 15% of the total A23187-releasable microsomal calcium store is insensitive to thapsigargin concentrations up to 100 mi...

Low prevalence of liver-kidney microsomal autoantibodies of type 1 (LKM1 in hepatitis C seropositive subjects on Crete, Greece

Directory of Open Access Journals (Sweden)

Pappas Georgios

2001-06-01

Full Text Available Abstract Background Hepatitis C is a serious problem on the Greek island of Crete, where a high prevalence of antibodies against hepatitis C (anti-HCV has recently been reported. This article reports the findings of a study carried out in Crete, which investigated the prevalence of serum autoantibodies in patients with chronic hepatitis C. Patients and Methods One hundred and forty two patients (59 men and 83 women, who were found anti-HCV seropositive in two hospitals and two Primary Health Care Centres in Crete, were eligible. Sixty healthy blood donors (46 men, 14 women, which were negative to anti-HCV, were used as the control group. They were randomly selected from those attending Rethymnon Hospital. Autoantibodies were identified using the indirect immunofluorescence (IFL technique on human epithelial cells from larynx cancer (HEp-2 cells, rat liver-kidney-stomach substrate (CT3 and Chrithidia Luciliae (CL. Results Serum autoantibodies were detected in 104 HCV patients, yielding an overall prevalence of 73.2%. The most frequent autoantibodies were antinuclear antibodies (ANA, positive in 72 patients (50.7%. Anti-smooth muscle antibodies (ASMA were detected in 33 patients (23.2%. Only one patient was positive for LKM1 autoantibodies. No autoantibodies were found in 38 patients (26.7%. Autoantibodies were also found in 5 out of the 60 examined healthy blood donors (8.3%. Conclusions Autoantibodies, mainly ANA and ASMA are very common in HCV seropositive patients from Crete. By contrast LKM1 autoantibodies are exceptionally rare in these patients.

Stereo-selectivity and regio-selectivity in the metabolism of 7,8-dihydrobenzo[a]pyrene by cytochrome P450, epoxide hydrolase and hepatic microsomes from 3-methylcholanthrene-treated rats.

Science.gov (United States)

Adams, J D; Yagi, H; Levin, W; Jerina, D M

1995-03-30

The active site of cytochrome P450 1A1 has been probed with the substrate 7,8-dihydrobenzo[a]pyrene using a purified, reconstituted system composed of cytochrome P450 1A1, NADPH-cytochrome c reductase and lipid in the presence or absence of epoxide hydrolase. The turnover of the substrate was found to be 38 nmol/nmol of cytochrome P450/min. The metabolic products that were identified are: a phenolic 7,8-dihydrobenzo[a]pyrene (20-29%); 9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (17-28%); benzo[a]pyrene (12-19%); 7-hydroxy-7,8-dihydrobenzo[a]pyrene (13-16%); 8-hydroxy-7,8-dihydrobenzo[a]pyrene (7-15%); 3-hydroxybenzo[a]pyrene (7-15%); 4,5-epoxy-4,5,7,8-tetrahydrobenzo[a]pyrene (0-4%); and a triol of 7,8,9,10-tetrahydrobenzo[a]pyrene (0-4%). 9,10-Epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene undergoes rapid hydrolysis to cis- and trans-9,10-dihydroxy-dihydroxy-7,8,9,10-tetrahydrobenzo[a]pyrene (2:1) by benzylic attack of water at C-10. Approximately 71% of the trans diols are derived from (+)-(9S,10R)-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene, indicating that cytochrome P450 1A1 has more than a 2:1 preference for selective epoxidation of an enantiotopic face of 7,8-dihydrobenzo[a]pyrene. This stereo-selectivity agrees with the postulated stereo-selectivity predicted by a previously described active site model for cytochrome P450 1A1. Epoxide hydrolase in pure form or in hepatic microsomes catalyzes the hydrolysis of 9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene, which is inhibited by 1,1,1-trichloropropane 2,3-oxide. The (+)-(9S,10R)-isomer of the epoxide is slightly preferred as a substrate over its enantiomer and is cleaved by benzylic and nonbenzylic attack. Only benzylic attack was found with (-)-(9R,10S)-9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene.

A Characterization of Carboxylesterases in Rat and Guinea Pig - Their Heterogeneity and Role in Detoxication of Organophosphorus Compounds

Science.gov (United States)

1993-09-01

of the glycoside detergent The rates of inactivation of different esterases. including saponin (final concn. I ’). w/w) to extract the microsomal...to be solubilized from rat liver microsomal membranes by treatment with a detergent like saponin (Mentlein et al., 1980), the CarbE activity of rat...coupled with the excellent selectivity of the Q and S substituents results in the high resolution separations characteristic of FPLC technology

The effect of elimination of environmental light on the metabolism of unconjugated bilirubin in the Gunn rat

International Nuclear Information System (INIS)

Zenone, E.A.; Stoll, M.S.; Ostrow, J.D.

1982-01-01

In the homozygous jaundiced Gunn rat, bilirubin catabolism is augmented by intense illumination (phototherapy) and by induction of microsomal cytochrome P448. To assess the relative importance of less intense environmental light versus intrinsic mechanisms in the maintenance of bilirubin turnover, Gunn rats were kept for three weeks under either ordinary laboratory lighting (0.3-0.8 mW/cm2, wavelength range 400-600 nm) or in absolute darkness. No differences in plasma concentration, miscible pool, turnover of bilirubin, or in hepatic cytochrome P448 activity were noted between the two groups over this period. A greater than twofold increase in the biliary excretion of unconjugated bilirubin was noted in the animals maintained under light, but this represented only 2% of total bilirubin turnover. These results suggest that intrinsic(enzymatic .) pathways are of primary importance in the maintenance of bilirubin metabolism in the glucuronyltransferase-deficient state under ordinary levels of environmental light

Sugary Kefir Strain Lactobacillus mali APS1 Ameliorated Hepatic Steatosis by Regulation of SIRT-1/Nrf-2 and Gut Microbiota in Rats.

Science.gov (United States)

Chen, Yung-Tsung; Lin, Yu-Chun; Lin, Jin-Seng; Yang, Ning-Sun; Chen, Ming-Ju

2018-04-01

Non-alcoholic fatty liver disease (NAFLD) is a common disease that is concomitant with obesity, resulting in increased mortality. To date, the efficiency of NAFLD treatment still needs to be improved. Therefore, we aimed to evaluate the effect of Lactobacillus mali APS1, which was isolated from sugary kefir, on hepatic steatosis in rats fed a high-fat diet (HFD). Sprague Dawley rats were fed a control diet, a HFD with saline, and a HFD with APS1 intervention by gavage daily for 12 weeks. The results showed that APS1 significantly reduced body weight and body weight gain in HFD-fed rats. APS1 reduced hepatic lipid accumulation by regulating SIRT-1/PGC-1α/SREBP-1 expression. Moreover, APS1 increased hepatic antioxidant activity by modulating Nrf-2/HO-1 expression. Notably, APS1 manipulated the gut microbiota, resulting in increasing proportions of the phylum Bacteroidetes/Firmicutes and reducing the abundance of specific NAFLD-associated bacteria. These results suggested that APS1 ameliorated hepatic steatosis by modulating lipid metabolism and antioxidant activity via manipulating specific NAFLD-associated gut microbiota in vivo. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Soybean meal fermented by Aspergillus awamori increases the cytochrome P-450 content of the liver microsomes of mice.

Science.gov (United States)

Kishida, T; Ataki, H; Takebe, M; Ebihara, K

2000-04-01

The effect of soybean meal fermented by Aspergillus awamori on the acute lethality of acetaldehyde, pentobarbital sleeping time, and cytochrome P-450 content of the hepatic microsomes was studied in mice. Most of the daidzin and genistin in soybean meal (SBM) were converted into the respective aglycones, daidzein and genistein, by fermentation. In experiment 1, mice were fed isonitrogenic test diets with one of the following five protein sources for 28 d: casein, SBM, fermented and hot-air-dried SBM (FSBM-HD), fermented and freeze-dried SBM (FSBM-FD), or methanol-extracted FSBM-FD (FSMB-FD-R). The acute lethality of acetaldehyde in mice fed the FSBM-FD diet was significantly lower than that in mice fed the SBM, FSBM-HD, or FSBM-FD-R diet. In experiments 2 and 3, mice were fed isonitrogenic test diets with one of the following four protein sources for 28 d: casein, SBM, FSBM-FD, and FSBM-FD-R. The pentobarbital sleeping time was significantly shorter and the cytochrome P-450 content was significantly higher in the mice fed the FSBM-FD diet than the respective value in mice fed the other test diets. In experiment 4, mice were fed one of eight diets which contained different levels of aglycone obtained by varying the proportion of FSBM-FD and FSBM-FD-R, for 28 d. The cytochrome P-450 content in hepatic microsomes increased as the dietary level of isoflavonoid aglycones increased, but there was a saturation phenomenon. These results suggest that soy isoflavonoid aglycones are more potent inducers of cytochrome P-450 than isoflavonoid glycosides.

188Re-SSS lipiodol: radiolabelling and biodistribution following injection into the hepatic artery of rats bearing hepatoma.

Science.gov (United States)

Garin, Etienne; Denizot, Benoit; Noiret, Nicolas; Lepareur, Nicolas; Roux, Jerome; Moreau, Myriam; Herry, Jean-Yves; Bourguet, Patrick; Benoit, Jean-Pierre; Lejeune, Jean-Jacques

2004-10-01

Although intra-arterial radiation therapy with 131I-lipiodol is a useful therapeutic approach to the treatment of hepatocellular carcinoma, various disadvantages limit its use. To describe the development of a method for the labelling of lipiodol with 188Re-SSS (188Re (S2CPh)(S3CPh)2 complex) and to investigate its biodistribution after injection into the hepatic artery of rats with hepatoma. 188Re-SSS lipiodol was obtained after dissolving a chelating agent, previously labelled with 188Re, in cold lipiodol. The radiochemical purity (RCP) of labelling was checked immediately. The 188Re-SSS lipiodol was injected into the hepatic artery of nine rats with a Novikoff hepatoma. They were sacrificed 1, 24 and 48 h after injection, and used for ex vivo counting. Labelling of 188Re-SSS lipiodol was achieved with a yield of 97.3+/-2.1%. The immediate RCP was 94.1+/-1.7%. Ex vivo counting confirmed a predominantly hepatic uptake, with a good tumoral retention of 188Re-SSS lipiodol, a weak pulmonary uptake and a very faint digestive uptake. The 'tumour/non-tumoral liver' ratio was high at 1, 24 and 48 h after injection (2.9+/-1.5, 4.1+/-/4.1 and 4.1+/-0.7, respectively). Using the method described here, 188Re-SSS lipiodol can be obtained with a very high yield and a satisfactory RCP. The biodistribution in rats with hepatoma indicates a good tumoral retention of 188Re-SSS lipiodol associated with a predominant hepatic uptake, a weak pulmonary uptake and a very faint digestive uptake. This product should be considered for intra-arterial radiation therapy in human hepatoma.

Subacute effects of hexabromocyclododecane (HBCD) on hepatic gene expression profiles in rats

International Nuclear Information System (INIS)

Canton, Rocio F.; Peijnenburg, Ad A.C.M.; Hoogenboom, Ron L.A.P.; Piersma, Aldert H.; Ven, Leo T.M. van der; Berg, Martin van den; Heneweer, Marjoke

2008-01-01

Hexabromoyclododecane (HBCD), used as flame retardant (FR) mainly in textile industry and in polystyrene foam manufacture, has been identified as a contaminant at levels comparable to other brominated FRs (BFRs). HBCD levels in biota are increasing slowly and seem to reflect the local market demand. The toxicological database of HBCD is too limited to perform at present a solid risk assessment, combining data from exposure and effect studies. In order to fill in some gaps, a 28-day HBCD repeated dose study (OECD407) was done in Wistar rats. In the present work liver tissues from these animals were used for gene expression profile analysis. Results show clear gender specificity with females having a higher number of regulated genes and therefore being more sensitive to HBCD than males. Several specific pathways were found to be affected by HBCD exposure, like PPAR-mediated regulation of lipid metabolism, triacylglycerol metabolism, cholesterol biosynthesis, and phase I and II pathways. These results were corroborated with quantitative RT-PCR analysis. Cholesterol biosynthesis and lipid metabolism were especially down-regulated in females. Genes involved in phase I and II metabolism were up-regulated predominantly in males, which could explain the observed lower HBCD hepatic disposition in male rats in this 28-day study. These sex-specific differences in gene expression profiles could also underlie sex-specific differences in toxicity (e.g. decreased thyroid hormone or increased serum cholesterol levels). To our knowledge, this is the fist study that describes the changes in rat hepatic gene profiles caused by this commonly used flame retardant

Lack of evidence for metabolism of p-phenylenediamine by human hepatic cytochrome P450 enzymes

International Nuclear Information System (INIS)

Stanley, Lesley A.; Skare, Julie A.; Doyle, Edward; Powrie, Robert; D'Angelo, Diane; Elcombe, Clifford R.

2005-01-01

p-Phenylenediamine (PPD) is a widely used ingredient in permanent hair dyes; however, little has been published on its metabolism, especially with respect to hepatic cytochrome P450 (CYP)-mediated oxidation. This is regarded as a key step in the activation of carcinogenic arylamines that ultimately leads to the development of bladder cancer. Most epidemiology studies show no significant association between personal use of hair dyes and bladder cancer, but one recent study reported an increased risk of bladder cancer in women who were frequent users of permanent hair dyes. The aim of the present study was to use intact human hepatocytes, human liver microsomes, and heterologously expressed human CYPs to determine whether PPD is metabolised by hepatic CYPs to form an N-hydroxylamine. p-Phenylenediamine was N-acetylated by human hepatocytes to form N-acetylated metabolites, but there was no evidence for the formation of mono-oxygenated metabolites or for enzyme-mediated covalent binding of 14 C-PPD to microsomal protein. In contrast, 2-aminofluorene underwent CYP-mediated metabolism to ≥4 different hydroxylated metabolites. The lack of evidence for hepatic CYP-mediated metabolism of PPD is inconsistent with the hypothesis that this compound plays a causal role in the development of bladder cancer via a mode of action involving hepatic metabolism to an N-hydroxyarylamine

Evaluation of Hepatic Steatosis by Using Acoustic Structure Quantification US in a Rat Model: Comparison with Pathologic Examination and MR Spectroscopy.

Science.gov (United States)

Lee, Dong Ho; Lee, Jae Young; Lee, Kyung Bun; Han, Joon Koo

2017-11-01

Purpose To determine factors that significantly affect the focal disturbance (FD) ratio calculated with an acoustic structure quantification (ASQ) technique in a dietary-induced fatty liver disease rat model and to assess the diagnostic performance of the FD ratio in the assessment of hepatic steatosis by using histopathologic examination as a standard of reference. Materials and Methods Twenty-eight male F344 rats were fed a methionine-choline-deficient diet with a variable duration (3.5 days [half week] or 1, 2, 3, 4, 5, or 6 weeks; four rats in each group). A control group of four rats was maintained on a standard diet. At the end of each diet period, ASQ ultrasonography (US) and magnetic resonance (MR) spectroscopy were performed. Then, the rat was sacrificed and histopathologic examination of the liver was performed. Receiver operating characteristic curve analysis was performed to assess the diagnostic performance of the FD ratio in the evaluation of the degree of hepatic steatosis. The Spearman correlation coefficient was calculated to assess the correlation between the ordinal values, and multivariate linear regression analysis was used to identify significant determinant factors for the FD ratio. Results The diagnostic performance of the FD ratio in the assessment of the degree of hepatic steatosis (area under the receiver operating characteristic curve: 1.000 for 5%-33% steatosis, 0.981 for >33% to 66% steatosis, and 0.965 for >66% steatosis) was excellent and was comparable to that of MR spectroscopy. There was a strong negative linear correlation between the FD ratio and the estimated fat fraction at MR spectroscopy (Spearman ρ, -0.903; P analysis showed that the degree of hepatic steatosis (P ratio. Conclusion The FD ratio may potentially provide good diagnostic performance in the assessment of the degree of hepatic steatosis, with a strong negative linear correlation with the estimated fat fraction at MR spectroscopy. The degree of steatosis and

Inhibitory effects of cytostatically active 6-aminobenzo[c]phenanthridines on cytochrome P450 enzymes in human hepatic microsomes.

Science.gov (United States)

Zebothsen, Inga; Kunze, Thomas; Clement, Bernd

2006-07-01

Besides assays for the evaluation of efficacy new drug candidates have to undergo extensive testings for enhancement of pharmaceutical drug safety and optimization of application. The objective of the present work was to investigate the pharmacokinetic drug drug interaction potential for the cytostatically active 6-aminobenzo[c]phenanthridines BP-11 (6-amino-11,12-dihydro-11-(4-hydroxy-3,5-dimethoxyphenyl)benzo[c]phenanthridine) and BP-D7 (6-amino-11-(3,4,5-trimethoxyphenyl)benzo[c]phenanthridine) in vitro through incubation with human hepatic microsomes and marker substrates. For these studies the cytochrome P-450 isoenzymes and corresponding marker substrates recommended by the EMEA (The European Agency for the Evaluation of Medicinal Products) were chosen. In detail these selective substrates were caffeine (CYP1A2), coumarin (CYP2A6), tolbutamide (CYP2C9), S-(+)-mephenytoin (CYP2C19), dextromethorphane (CYP2D6), chlorzoxazone (CYP2E1) and testosterone (CYP3A4). Incubations with each substrate were carried out without a possible inhibitor and in the presence of a benzo[c]phenanthridine or a selective inhibitor at varying concentrations. Marker activities were determined by HPLC (high performance liquid chromatography). For the isoenzymes showing more than 50% inhibition by the addition of 20 microM BP-11 or BP-D7 additional concentrations of substrate and inhibitor were tested for a characterization of the inhibition. The studies showed a moderate risk for BP-11 for interactions with the cytochrome P-450 isoenzymes CYP1A2, CYP2C9, CYP2D6 and CYP3A4. BP-D7, the compound with the highest cytotstatic efficacy, showed only a moderate risk for interactions with drugs, also metabolized by CYP3A4.

Early radiation impairment of the cholesterol metabolism in organelles of rat liver cells

Energy Technology Data Exchange (ETDEWEB)

Kaznacherev, Yu S; Kolomiitseva, I K [AN SSSR, Pushchino-na-Oke. Inst. Biologicheskoj Fiziki

1975-05-01

The incorporation of 1-C/sup 14/-acetate into cholesterol of the nuclear, mitochondrial, microsomal and 105000 g-supernatant fractions isolated from the rat liver in norm and 60 min after the exposure to 1200 r has been investigated. An increase has been observed in the label uptake into liver cholesterol of irradiated rats. Intracellular distribution of the newly synthesized (labelled) cholesterol is substantially changed after irradiation: maximum label incorporation into the cholesterol is observed in the 105000 g-supernatant fraction, whereas, normally, the cholesterol of microsomal fraction has the highest specific activity.

Establishment of a novel radioligand assay using eukaryotically expressed cytochrome P4502D6 for the measurement of liver kidney microsomal type 1 antibody in patients with autoimmune hepatitis and hepatitis C virus infection.

Science.gov (United States)

Ma, Y; Gregorio, G; Gäken, J; Muratori, L; Bianchi, F B; Mieli-Vergani, G; Vergani, D

1997-06-01

Liver kidney microsomal type 1 antibody (LKM1) is the diagnostic marker of autoimmune hepatitis (AIH) type 2 and is also found in patients with hepatitis C virus (HCV) infection. Cytochrome P4502D6 (CYP2D6) is the documented target antigen of LKM1 in AIH, but not in HCV infection. To compare the reactivity in the two conditions, we established a radioligand assay using eukaryotically expressed CYP2D6 as target. A 1.2-kb human CYP2D6 cDNA was isolated from a human liver cDNA library and subcloned into an in vitro transcription vector pSP64 Poly(A). Recombinant CYP2D6 was then produced by in vitro transcription/translation, metabolically labelled with 35S methionine and used in the immunoprecipitation assay. Antibodies that bound radiolabelled CYP2D6 were immunoprecipitated and their levels assessed as cpm. Sera from 50 LKM1-positive patients (26 with AIH; 24 with HCV infection), 128 LKM1-negative patients and 57 normal controls were tested. Reactivity to 35S labelled CYP2D6 was observed in all LKM1-positive sera from patients with AIH and HCV infection, but in none of the controls. The cpm in both conditions were significantly higher than in normal controls (pLKM1 (r 0.87, p<0.001 and r=0.64, p<0.001 for AIH and HCV infection, respectively). Reactivity to 35S labelled CYP2D6 was inhibited by addition of an excess of eukaryotically expressed CYP2D6. CYP2D6 is a major target antigen of both AIH and HCV infection. The novel radioligand assay is highly sensitive and specific.

Lead nitrate-induced development of hypercholesterolemia in rats: sterol-independent gene regulation of hepatic enzymes responsible for cholesterol homeostasis.

Science.gov (United States)

Kojima, Misaki; Masui, Toshimitsu; Nemoto, Kiyomitsu; Degawa, Masakuni

2004-12-01

Changes in the gene expressions of hepatic enzymes responsible for cholesterol homeostasis were examined during the process of lead nitrate (LN)-induced development of hypercholesterolemia in male rats. Total cholesterol levels in the liver and serum were significantly increased at 3-72 h and 12-72 h, respectively, after LN-treatment (100 micromol/kg, i.v.). Despite the development of hypercholesterolemia, the genes for hepatic 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) and other enzymes (FPPS, farnesyl diphosphate synthase; SQS, squalene synthase; CYP51, lanosterol 14alpha-demethylase) responsible for cholesterol biosynthesis were activated at 3-24 h and 12-18 h, respectively. On the other hand, the gene expression of cholesterol 7alpha-hydroxylase (CYP7A1), a catabolic enzyme of cholesterol, was remarkably suppressed at 3-72 h. The gene expression levels of cytokines interleukin-1beta (IL-1beta) and TNF-alpha, which activate the HMGR gene and suppress the CYP7A1 gene, were significantly increased at 1-3 h and 3-24 h, respectively. Furthermore, gene activation of SREBP-2, a gene activator of several cholesterogenic enzymes, occurred before the gene activations of FPPS, SQS and CYP51. This is the first report demonstrating sterol-independent gene regulation of hepatic enzymes responsible for cholesterol homeostasis in LN-treated male rats. The mechanisms for the altered-gene expressions of hepatic enzymes in LN-treated rats are discussed.

Activation of peroxisome proliferator-activated receptor gamma by rosiglitazone increases sirt6 expression and ameliorates hepatic steatosis in rats.

Directory of Open Access Journals (Sweden)

Soo Jin Yang

Full Text Available BACKGROUND: Sirt6 has been implicated in the regulation of hepatic lipid metabolism and the development of hepatic steatosis. The aim of this study was to address the potential role of Sirt6 in the protective effects of rosiglitazone (RGZ on hepatic steatosis. METHODS: To investigate the effect of RGZ on hepatic steatosis, rats were treated with RGZ (4 mg·kg⁻¹·day⁻¹ by stomach gavage for 6 weeks. The involvement of Sirt6 in the RGZ's regulation was evaluated by Sirt6 knockdown in AML12 mouse hepatocytes. RESULTS: RGZ treatment ameliorated hepatic lipid accumulation and increased expression of Sirt6, peroxisome proliferator-activated receptor gamma coactivtor-1-α (Ppargc1a/PGC1-α and Forkhead box O1 (Foxo1 in rat livers. AMP-activated protein kinase (AMPK phosphorylation was also increased by RGZ, accompanied by alterations in phosphorylation of LKB1. Interestingly, in free fatty acid-treated cells, Sirt6 knockdown increased hepatocyte lipid accumulation measured as increased triglyceride contents (p = 0.035, suggesting that Sirt6 may be beneficial in reducing hepatic fat accumulation. In addition, Sirt6 knockdown abolished the effects of RGZ on hepatocyte fat accumulation, mRNA and protein expression of Ppargc1a/PGC1-α and Foxo1, and phosphorylation levels of LKB1 and AMPK, suggesting that Sirt6 is involved in RGZ-mediated metabolic effects. CONCLUSION: Our results demonstrate that RGZ significantly decreased hepatic lipid accumulation, and that this process appeared to be mediated by the activation of the Sirt6-AMPK pathway. We propose Sirt6 as a possible therapeutic target for hepatic steatosis.

Modulation of hepatic inflammation and energy-sensing pathways in the rat liver by high-fructose diet and chronic stress.

Science.gov (United States)

Veličković, Nataša; Teofilović, Ana; Ilić, Dragana; Djordjevic, Ana; Vojnović Milutinović, Danijela; Petrović, Snježana; Preitner, Frederic; Tappy, Luc; Matić, Gordana

2018-05-29

High-fructose consumption and chronic stress are both associated with metabolic inflammation and insulin resistance. Recently, disturbed activity of energy sensor AMP-activated protein kinase (AMPK) was recognized as mediator between nutrient-induced stress and inflammation. Thus, we analyzed the effects of high-fructose diet, alone or in combination with chronic stress, on glucose homeostasis, inflammation and expression of energy sensing proteins in the rat liver. In male Wistar rats exposed to 9-week 20% fructose diet and/or 4-week chronic unpredictable stress we measured plasma and hepatic corticosterone level, indicators of glucose homeostasis and lipid metabolism, hepatic inflammation (pro- and anti-inflammatory cytokine levels, Toll-like receptor 4, NLRP3, activation of NFκB, JNK and ERK pathways) and levels of energy-sensing proteins AMPK, SIRT1 and peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α). High-fructose diet led to glucose intolerance, activation of NFκB and JNK pathways and increased intrahepatic IL-1β, TNFα and inhibitory phosphorylation of insulin receptor substrate 1 on Ser 307 . It also decreased phospho-AMPK/AMPK ratio and increased SIRT1 expression. Stress alone increased plasma and hepatic corticosterone but did not influence glucose tolerance, nor hepatic inflammatory or energy-sensing proteins. After the combined treatment, hepatic corticosterone was increased, glucose tolerance remained preserved, while hepatic inflammation was partially prevented despite decreased AMPK activity. High-fructose diet resulted in glucose intolerance, hepatic inflammation, decreased AMPK activity and reduced insulin sensitivity. Chronic stress alone did not exert such effects, but when applied together with high-fructose diet it could partially prevent fructose-induced inflammation, presumably due to increased hepatic glucocorticoids.

Non-organ specific autoantibodies in children with chronic hepatitis C.

Science.gov (United States)

Bortolotti, F; Vajro, P; Balli, F; Giacchino, R; Crivellaro, C; Barbera, C; Cataleta, M; Muratori, L; Pontisso, P; Nebbia, G; Zancan, L; Bertolini, A; Alberti, A; Bianchi, F

1996-11-01

Recent studies in adult patients have established a relationship between hepatitis C virus infection and the presence of liver-kidney microsomal autoantibody type 1 (LKM1). Conversely, little is known regarding the relationship between hepatitis C and autoimmunity in children. In this study, we investigated non-organ specific autoantibodies in 40 otherwise healthy Italian children with chronic hepatitis C. All but four patients included in the study were asymptomatic. Liver histology, obtained in 35, showed features ranging from minimal to mild chronic hepatitis. Autoantibodies were investigated by indirect immunofluorescence. HCV RNA was assayed by the polymerase chain reaction in 34 cases and viral genotypes were determined. Antinuclear antibodies were detected in three (7.5%) cases, one with a homogeneous pattern; smooth muscle autoantibodies in seven (17.5%) cases, always with V (vessels only) specificity and LKM1 in four (10%), at titers ranging from 1:20 and 1:2560. Clinical and virologic features did not significantly differ between autoantibody positive and negative cases, although infections with HCV genotypes 1a and 2 were more frequent in LKM1-positive patients. During observation, the child with the highest LKM1 titre was unsuccessfully treated with alpha interferon but responded to steroids. Twelve LKM1 negative children were also treated with interferon and one developed low LKM1 titers concomitant with an alanine aminotransferase flare. The sera of the five LKM1-positive children with investigated by immunoblotting with a human microsomal fraction and peptide 257-269 of cytochrome P450IID6. Only the serum of the child with the highest LKM1 titers was reactive. These results show that a consistent proportion of children with chronic hepatitis C circulate non-organ specific autoantibodies. The prevalence of LKM1 is greater than in adults and this could raise problems for the treatment of the disease with interferon. The analysis of LKM1 target antigens

[EFFECT OF ACETYLCYSTEINE, CORVITIN AND THEIR COMBINATION ON THE FUNCTIONAL STATE OF LIVER IN RATS WITH PARACETAMOL INDUCED TOXIC HEPATITIS].

Science.gov (United States)

Ghonghadze, M; Antelava, N; Liluashvili, K; Okujava, M; Pachkoria, K

2017-02-01

Nowadays drug-induced hepatotoxicity is urgent problem worldwide. Currently more than 1000 drugs are hepatotoxic and most often are the reason of acute fulminant hepatitis and hepatocellular failure, the states requiring liver transplantation. The paracetamol induced liver toxicity is related with accumulation of its toxic metabolite N-acetyl-p-benzoquinone imine (NAPQI), which is the free radical and enhances peroxidation of lipids, disturbs the energy status and causes death of hepatocytes. During our research we investigated and assessed the efficacy of acetylcysteine, corvitin and their combination in rat model of paracetamol induced acute toxic hepatitis. The study was performed on mature white male Wistar rates with body mass 150-180 g. 50 rats were randomly divided into 5 groups (10 rats in each group). To get the model of acute toxic hepatitis single intraperitoneal injection of paracetamol solution was used (750 mg/kg). Toxic hepatitis was treated with intrapertoneal administration of 40mg/kg acetylcysteine or 100mg/kg corvitin, as well as with combination of these drugs. Monotherapy with acetylcysteine and corvitin of paracetamol induced toxic hepatitis improved the liver function, decreased relative mass of the liver and animal mortality. The treatment of toxic hepatitis was most effective in the case of simultaneous administration of acetylcysteine and corvitin. The normal value of laboratory tests (ALT, ACT, alkaline phosphatase, total and unconjugated bilirubin) was reached and mortality was not more observed. On the bases of obtained data was concluded that acetylcysteine and corvitin have almost equal hepatoprotective activity. The combination of two drugs actually improves the liver function. The most pronounced hepatoprotective effect may be due to synergic action of acetylcysteine and corvitin and such regime can be recommended for correction of liver function.

Dietary Supplementation with Virgin Coconut Oil Improves Lipid Profile and Hepatic Antioxidant Status and Has Potential Benefits on Cardiovascular Risk Indices in Normal Rats.

Science.gov (United States)

Famurewa, Ademola C; Ekeleme-Egedigwe, Chima A; Nwali, Sophia C; Agbo, Ngozi N; Obi, Joy N; Ezechukwu, Goodness C

2018-05-04

Research findings that suggest beneficial health effects of dietary supplementation with virgin coconut oil (VCO) are limited in the published literature. This study investigated the in vivo effects of a 5-week VCO-supplemented diet on lipid profile, hepatic antioxidant status, hepatorenal function, and cardiovascular risk indices in normal rats. Rats were randomly divided into 3 groups: 1 control and 2 treatment groups (10% and 15% VCO-supplemented diets) for 5 weeks. Serum and homogenate samples were used to analyze lipid profile, hepatorenal function markers, hepatic activities of antioxidant enzymes, and malondialdehyde level. Lipid profile of animals fed VCO diets showed significant reduction in total cholesterol (TC), triglyceride (TG), and low-density lipoprotein (LDL) levels; high-density lipoprotein (HDL) level increased significantly (p risk indices. The level of malondialdehyde (MDA), a lipid peroxidation marker, remarkably reduced and activities of hepatic antioxidant enzymes-superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx)-were markedly increased in VCO diet-fed rats. The VCO diet significantly modulated creatinine, sodium (Na + ), potassium (K + ), chloride (Cl - ), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) compared to control. The findings suggest a beneficial effect of VCO on lipid profile, renal status, hepatic antioxidant defense system, and cardiovascular risk indices in rats.

Artesunate prevents rats from the clozapine-induced hepatic steatosis and elevation in plasma triglycerides

Directory of Open Access Journals (Sweden)

Li Y

2017-09-01

Full Text Available Yanmei Li,1,2 Ruibing Su,3 Shuqin Xu,2 Qingjun Huang,1 Haiyun Xu1,2 1The Mental Health Center, Shantou University Medical College, Shantou, Guangdong Province, People’s Republic of China; 2Department of Anatomy, Shantou University Medical College, Shantou, Guangdong Province, People’s Republic of China; 3Department of Forensics and Pathology, Shantou University Medical College, Shantou, Guangdong Province, People’s Republic of China Abstract: Clozapine is an atypical antipsychotic with therapeutic efficacy in treatment-resistant schizophrenia patients and low incidence of extrapyramidal side effects. However, the use of clozapine has been limited by its adverse effects on metabolism. Artesunate is a semisynthetic derivative of artemisinin and was shown to decrease the plasma cholesterol and triglyceride in rabbits and rats in recent studies. The aim of this study was to examine possible effects of artesunate on the clozapine-induced metabolic alterations in rats given saline, clozapine, artesunate, or clozapine plus artesunate for 6 weeks. The clozapine group showed significantly high plasma levels of triglyceride, hepatic steatosis, and fibrosis along with high levels of C-reactive protein, alanine aminotransferase, and aspartate aminotransferase compared to the saline group. But the treatment had no effect on weight gain and caused no hyperglycemia, hyperinsulinemia, and behavioral changes in the rats. More significantly, these clozapine-induced changes were not seen in rats coadministered with clozapine plus artesunate. These results added evidence supporting psychiatrists to try add-on treatment of artesunate in schizophrenia patients to ameliorate clozapine-induced adverse metabolic effects. Keywords: artesunate, clozapine, dyslipidemia, hepatic steatosis, schizophrenia 

Intraportal nicotine infusion in rats decreases hepatic blood flow through endothelin-1 and both endothelin A and endothelin B receptors

International Nuclear Information System (INIS)

Hashimoto, Takashi; Yoneda, Masashi; Shimada, Tadahito; Kurosawa, Mieko; Terano, Akira

2004-01-01

Smoking has been demonstrated to aggravate liver injury. Nicotine, a major pharmacological component of tobacco smoke, affects a multitude of functions. Smoking and nicotine induce synthesis of endothelin (ET)-1. The effect of intraportal infusion of nicotine on hepatic circulation and an involvement of ET-1 and ET receptor in the action of nicotine were investigated in rats. Nicotine (0-100 μg/kg/h) was infused into the portal vein of urethane-anesthetized rats, and changes of hepatic blood flow were evaluated. Intraportal infusion of nicotine dose-dependently decreased hepatic blood flow and increased portal pressure without any alteration of heart rate or arterial blood pressure. This action of intraportal nicotine was completely abolished by pretreatment of ET-1 antibody. Either BQ485 (ET A receptor antagonist) or BQ788 (ET B receptor antagonist) partially reversed the effect of nicotine, and combination of BQ788 and BQ485 completely abolished it. These findings suggest that nicotine inhibits hepatic circulation through ET-1, and ET A and ET B receptor

Salacia oblonga root improves postprandial hyperlipidemia and hepatic steatosis in Zucker diabetic fatty rats: Activation of PPAR-α

International Nuclear Information System (INIS)

Hsun-Wei Huang, Tom; Peng Gang; Qian Li, George; Yamahara, Johji; Roufogalis, Basil D.; Li Yuhao

2006-01-01

Salacia oblonga (SO) root is an Ayurvedic medicine with anti-diabetic and anti-obese properties. Peroxisome proliferator-activated receptor (PPAR)-α, a nuclear receptor, plays an important role in maintaining the homeostasis of lipid metabolism. Here, we demonstrate that chronic oral administration of the water extract from the root of SO to Zucker diabetic fatty (ZDF) rats, a genetic model of type 2 diabetes and obesity, lowered plasma triglyceride and total cholesterol (TC) levels, increased plasma high-density lipoprotein levels and reduced the liver contents of triglyceride, non-esterified fatty acids (NEFA) and the ratio of fatty droplets to total tissue. By contrast, the extract had no effect on plasma triglyceride and TC levels in fasted ZDF rats. After olive oil administration to ZDF the extract also inhibited the increase in plasma triglyceride levels. These results suggest that SO extract improves postprandial hyperlipidemia and hepatic steatosis in ZDF rats. Additionally, SO treatment enhanced hepatic expression of PPAR-α mRNA and protein, and carnitine palmitoyltransferase-1 and acyl-CoA oxidase mRNAs in ZDF rats. In vitro, SO extract and its main component mangiferin activated PPAR-α luciferase activity in human embryonic kidney 293 cells and lipoprotein lipase mRNA expression and enzyme activity in THP-1 differentiated macrophages; these effects were completely suppressed by a selective PPAR-α antagonist MK-886. The findings from both in vivo and in vitro suggest that SO extract functions as a PPAR-α activator, providing a potential mechanism for improvement of postprandial hyperlipidemia and hepatic steatosis in diabetes and obesity

Influence of Chloramphenicol and Amoxicillin on Rat Liver ...

African Journals Online (AJOL)

This study examined the effect of chloramphenicol and amoxicillin on liver microsomal enzymes Ca2+-ATPase and Glucose-6-Phosphatase (G-6-P) and lipid peroxidation in rats. Male Wistar strain rats weighing 120 – 195 g were divided into four groups. Group one, the control group, received physiological saline, group ...

Enhanced hepatic insulin signaling in the livers of high altitude native rats under basal conditions and in the livers of low altitude native rats under insulin stimulation: a mechanistic study.

Science.gov (United States)

Al Dera, Hussain; Eleawa, Samy M; Al-Hashem, Fahaid H; Mahzari, Moeber M; Hoja, Ibrahim; Al Khateeb, Mahmoud

2017-07-01

This study was designed to investigate the role of the liver in lowering fasting blood glucose levels (FBG) in rats native to high (HA) and low altitude (LA) areas. As compared with LA natives, besides the improved insulin and glucose tolerance, HA native rats had lower FBG, at least mediated by inhibition of hepatic gluconeogenesis and activation of glycogen synthesis. An effect that is mediated by the enhancement of hepatic insulin signaling mediated by the decreased phosphorylation of TSC induced inhibition of mTOR function. Such effect was independent of activation of AMPK nor stabilization of HIF1α, but most probably due to oxidative stress induced REDD1 expression. However, under insulin stimulation, and in spite of the less activated mTOR function in HA native rats, LA native rats had higher glycogen content and reduced levels of gluconeogenic enzymes with a more enhanced insulin signaling, mainly due to higher levels of p-IRS1 (tyr612).

Vitamin C and E chronic supplementation differentially affect hepatic insulin signaling in rats.

Science.gov (United States)

Ali, Mennatallah A; Eid, Rania M H M; Hanafi, Mervat Y

2018-02-01

Vitamin C and vitamin E supplementations and their beneficial effects on type 2 diabetes mellitus (T2DM) have been subjected to countless controversial data. Hence, our aim is to investigate the hepatic molecular mechanisms of any diabetic predisposing risk of the chronic administration of different doses of vitamin E or vitamin C in rats. The rats were supplemented with different doses of vitamin C or vitamin E for eight months. Vitamin C and vitamin E increased fasting blood glucose, insulin, and homeostasis model assessment index for insulin resistance (HOMA). Vitamin C disrupted glucose tolerance by attenuating upstream hepatic insulin action through impairing the phosphorylation and activation of insulin receptor and its subsequent substrates; however, vitamin E showed its effect downstream insulin receptor in the insulin signaling pathway, reducing hepatic glucose transporter-2 (GLUT2) and phosphorylated protein kinase (p-Akt). Moreover, both vitamins showed their antioxidant capabilities [nuclear factor-erythroid-2-related factor 2 (Nrf2), total and reduced glutathione] and their negative effect on Wnt pathway [phosphorylated glycogen synthase kinase-3β (p-GSK-3β)], by altering the previously mentioned parameters, inevitably leading to severe reduction of reactive oxygen species (ROS) below the physiological levels. In conclusion, a detrimental effect of chronic antioxidant vitamins supplementation was detected; leading to insulin resistance and impaired glucose tolerance obviously through different mechanisms. Overall, these findings indicate that the conventional view that vitamins promote health benefits and delay chronic illnesses and aging should be modified or applied with caution. Copyright © 2017. Published by Elsevier Inc.

Short-term hepatic effects of depleted uranium on xenobiotic and bile acid metabolizing cytochrome P450 enzymes in the rat

International Nuclear Information System (INIS)

Gueguen, Y.; Souidi, M.; Baudelin, C.; Dudoignon, N.; Grison, S.; Dublineau, I.; Marquette, C.; Voisin, P.; Gourmelon, P.; Aigueperse, J.

2006-01-01

The toxicity of uranium has been demonstrated in different organs, including the kidneys, skeleton, central nervous system, and liver. However, few works have investigated the biological effects of uranium contamination on important metabolic function in the liver. In vivo studies were conducted to evaluate its effects on cytochrome P450 (CYP) enzymes involved in the metabolism of cholesterol and xenobiotics in the rat liver. The effects of depleted uranium (DU) contamination on Sprague-Dawley were measured at 1 and 3 days after exposure. Biochemical indicators characterizing liver and kidney functions were measured in the plasma. The DU affected bile acid CYP activity: 7α-hydroxycholesterol plasma level decreased by 52% at day 3 whereas microsomal CYP7A1 activity in the liver did not change significantly and mitochondrial CYP27A1 activity quintupled at day 1. Gene expression of the nuclear receptors related to lipid metabolism (FXR and LXR) also changed, while PPARα mRNA levels did not. The increased mRNA levels of the xenobiotic-metabolizing CYP3A enzyme at day 3 may be caused by feedback up-regulation due to the decreased CYP3A activity at day 1. CAR mRNA levels, which tripled on day 1, may be involved in this up-regulation, while mRNA levels of PXR did not change. These results indicate that high levels of depleted uranium, acting through modulation of the CYP enzymes and some of their nuclear receptors, affect the hepatic metabolism of bile acids and xenobiotics. (orig.)

Bisphenol A induces oxidative stress and DNA damage in hepatic tissue of female rat offspring

Directory of Open Access Journals (Sweden)

Jehane I. Eid

2015-08-01

Full Text Available Bisphenol A (BPA is an endocrine disrupting compound widely spread in our living environment. It is a contaminant with increasing exposure to it and exerts both toxic and estrogenic effects on mammalian cells. Due to the limited information concerning the effect of BPA on the liver, the present study was designed to assess hepatic tissue injury induced by early life exposure to BPA in female rat offspring. Rat dams (n = 9 were gavaged with 0.5 and 50 mg of BPA/kg b.w./day throughout lactation until weaning. The sham group received olive oil for the same duration while the control group did not receive any injection. The liver tissue was collected from female pups at different pubertal periods (PND50, 90 and 110 to evaluate oxidative stress biomarkers, extent of DNA damage and histopathological changes. Our results indicated that early life exposure to BPA significantly increased oxidative/nitrosative stress, decreased antioxidant enzyme activities, induced DNA damage and chronic severe inflammation in the hepatic tissue in a time dependent manner. These data suggested that BPA causes long-term adverse effects on the liver, which leads to deleterious effects in the liver of female rat offspring.

Autoimmune hepatitis.

Science.gov (United States)

Vergani, D; Mieli-Vergani, G

2004-06-01

Autoimmune hepatitis (AIH) is characterised histologically by interface hepatitis, and serologically by the presence of non-organ and liver specific autoantibodies and increased levels of immunoglobulin G. Its onset is often ill-defined, frequently mimicing acute hepatitis. AIH usually responds to immunosuppressive treatment, which should be instituted as soon as diagnosis is made. Two types of AIH are recognized according to seropositivity for smooth muscle and/or antinuclear antibody (SMA/ANA, type 1 AIH) or liver kidney microsomal type 1 antibody (LKM1, type 2 AIH). There is a female predominance in both. LKM1 positive patients tend to present more acutely, at a younger age and commonly have immunoglobulin A deficiency, while duration of symptoms before diagnosis, clinical signs, family history of autoimmunity, presence of associated autoimmune disorders, response to treatment and long-term prognosis are similar in the 2 groups. Susceptibility to AIH type 1 is conferred by possession of HLA DR3 and DR4, while to AIH type 2 by possession of HLA DR7. Liver damage is likely to derive from an immune reaction to liver cell antigens, possibly triggered by a mechanism of molecular mimicry, where immune responses to external pathogens, e.g. viruses, become directed towards structurally similar self-components. In AIH this process would be perpetuated by impairment in immune regulation.

Virgin coconut oil reverses hepatic steatosis by restoring redox homeostasis and lipid metabolism in male Wistar rats.

Science.gov (United States)

Narayanankutty, Arunaksharan; Palliyil, Devika Mukundan; Kuruvilla, Kezia; Raghavamenon, Achuthan C

2018-03-01

Hepatosteatosis, a form of nonalcoholic fatty liver disease (NAFLD), is being increasingly recognized as a major health burden worldwide. Insulin resistance, dyslipidemia and imbalances in adipokine/cytokine interplay are reported to be involved in the onset and progression of this disease. Use of dietary nutraceuticals in prevention and treatment of NAFLD is emerging. Virgin coconut oil (VCO), a fermented product of fresh coconut kernel, has been shown to impede the development of hepatosteatosis in rats. This study analyzes the potential of VCO to reverse the already developed hepatosteatosis condition. Hyperglycemia, reduced glucose tolerance, dyslipidemia, and hepatic macrovesicles in high-fructose-diet-fed rats (4 weeks) confirmed the development of hepatosteatosis. Natural reversion in these parameters was observed upon shifting to normal diet in untreated control animals. Administration of VCO, however, increased this natural reversion by improving high-density lipoprotein cholesterol level (53.5%) and reducing hepatic and serum triacylglycerols (78.0 and 51.7%). Increased hepatic glutathione level (P < 0.01), antioxidant enzyme activities (P < 0.05) and reduced lipid peroxidation were also noticed in these animals. These observations were in concordance with reduced liver enzyme activities (P < 0.01) and restoration of altered hepatic architecture. The study indicates that VCO can be used as a nutraceutical against hepatosteatosis. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Daily fluctuation of hepatic P450 monooxygenase activities in male rats is controlled by the suprachiasmatic nucleus but remains unaffected by adrenal hormones.

Science.gov (United States)

Furukawa, T; Manabe, S; Watanabe, T; Sehata, S; Sharyo, S; Okada, T; Mori, Y

1999-09-01

Hepatic P450 monooxygenase activities, which strongly influence the efficacy and/or toxicity of drugs, are known to fluctuate daily. We also know that the P450 activities assessed by measurement of 7-alkoxycoumarin O-dealkylase (ACD) activities fluctuate daily, with apparently high values during the dark period in male rats. However, there is little knowledge about the factors that regulate daily fluctuation of P450 monooxygenase activities. In the present study using rats, we induced lesions in the suprachiasmatic nucleus (SCN) of the brain, the known site of the body's internal clock, and examined the effects on the daily fluctuation of the ACD activities to clarify the relationship between the SCN and the daily fluctuation of P450 monooxygenase activities. In addition, adrenalectomy was performed to re-evaluate the influence of adrenal hormones on the P450 activities. Our results indicated that daily fluctuations of the hepatic ACD activities were completely eliminated in the SCN-lesioned rats. However, the ACD activities in the adrenalectomized rats showed apparent daily fluctuations with high values during the dark period and low values during the light period. Therefore, this study demonstrated that the daily fluctuation of the hepatic P450 monooxygenase activities in male rats is controlled by the SCN but remains unaffected by the adrenal hormones.

Halofuginone ameliorates inflammation in severe acute hepatitis B virus (HBV-infected SD rats through AMPK activation

Directory of Open Access Journals (Sweden)

Zhan WL

2017-10-01

Full Text Available Weili Zhan, Yanhong Kang, Ning Chen, Chongshan Mao, Yi Kang, Jia Shang Department of Infectious Diseases, Henan Provincial People’s Hospital, Zhengzhou, Henan, China Abstract: The hepatitis B virus (HBV has caused acute and chronic liver diseases in ~350 million infected people worldwide. Halofuginone (HF is a plant alkaloid which has been demonstrated to play a crucial role in immune regulation. Our present study explored the function of HF in the immune response of HBV-infected Sprague Dawley (SD rats. Plasmid containing pCDNA3.1-HBV1.3 was injected in SD rats for the construction of an acute HBV-infected animal model. Our data showed that HF reduced the high concentrations of serum hepatitis B e-antigen, hepatitis B surface antigen, and HBV DNA induced by HBV infection. HF also reduced the number of T helper (Th17 cells and the expression of interleukin (IL-17 compared with the pCDNA3.1-HBV1.3 group. Moreover, pro-inflammatory cytokine levels (IL-17, IL-23, interferon-γ, and IL-2 were downregulated and anti-inflammatory cytokine levels (IL-4 and IL-13 were upregulated by HF. Through further research we found that the expression of AMP-activated protein kinase (AMPK and IKBA which suppressed NF-κB activation was increased while the expression of p-NF-κB P65 was decreased in pCDNA3.1-HBV1.3+HF group compared with pCDNA3.1-HBV1.3 group, indicating that HF may work through the activation of AMPK. Finally, our conjecture was further verified by using the AMPK inhibitor compound C, which counteracted the anti-inflammation effect of HF, resulting in the decreased expression of AMPK, IKBA and increased expression of p-NF-κB P65 and reduced number of Th17 cells. In our present study, HF was considered as an anti-inflammatory factor in acute HBV-infected SD rats and worked through AMPK-mediated NF-κB p65 inactivation. This study implicated HF as a potential therapeutic strategy for hepatitis B. Keywords: halofuginone, hepatitis B virus

Cytochrome P-450 complex formation in rat liver by the antibiotic tiamulin.

Science.gov (United States)

Witkamp, R F; Nijmeijer, S M; van Miert, A S

1996-01-01

Tiamulin is a semisynthetic diterpene antibiotic frequently used in farm animals. The drug has been shown to produce clinically important--often lethal--interactions with other compounds. It has been suggested that this is caused by a selective inhibition of oxidative drug metabolism via the formation of a cytochrome P-450 metabolic intermediate complex. In the present study, rats were treated orally for 6 days with tiamulin at two different doses: 40 and 226 mg/kg of body weight. For comparison, another group received 300 mg of triacetyloleandomycin (TAO) per kg, which is equivalent to the 226-mg/kg tiamulin group. Subsequently, microsomal P-450 contents, P-450 enzyme activities, metabolic intermediate complex spectra, and P-450 apoprotein concentrations were assessed. In addition, effects on individual microsomal P-450 activities were studied in control microsomes at different tiamulin and substrate concentrations. In the rats treated with tiamulin, a dose-dependent complex formation as evidenced by its absorption spectrum and an increase in cytochrome P-4503A1/2 contents as assessed by Western blotting (immunoblotting) were found. The effects were comparable to those of TAO. Tiamulin induced microsomal P-450 content, testosterone 6 beta-hydroxylation rate, erythromycin N-demethylation rate, and the ethoxyresorufin O-deethylation activity. Other activities were not affected or decreased. When tiamulin was added to microsomes of control rats, the testosterone 6 beta-hydroxylation rate and the erythromycin N-demethylation were strongly inhibited. It is concluded that tiamulin is a potent and selective inducer-inhibitor of cytochrome P-450. Though not belonging to the macrolides, the compound produces an effect on P-450 similar to those of TAO and related compounds.

Overexpression of Catalase Enhances Benzo(a)pyrene Detoxification in Endothelial Microsomes.

Science.gov (United States)

Yang, Fang; Yang, Hong; Ramesh, Aramandla; Goodwin, J Shawn; Okoro, Emmanuel U; Guo, ZhongMao

2016-01-01

We previously reported that overexpression of catalase upregulated xenobiotic- metabolizing enzyme (XME) expression and diminished benzo(a)pyrene (BaP) intermediate accumulation in mouse aortic endothelial cells (MAECs). Endoplasmic reticulum (ER) is the most active organelle involved in BaP metabolism. To examine the involvement of ER in catalase-induced BaP detoxification, we compared the level and distribution of XMEs, and the profile of BaP intermediates in the microsomes of wild-type and catalase transgenic endothelial cells. Our data showed that endothelial microsomes were enriched in cytochrome P450 (CYP) 1A1, CYP1B1 and epoxide hydrolase 1 (EH1), and contained considerable levels of quinone oxidoreductase-1 (NQO1) and glutathione S-transferase-pi (GSTP). Treatment of wild-type MAECs with 1μM BaP for 2 h increased the expression of microsomal CYP1A1, 1B1 and NQO1 by ~300, 64 and 116%, respectively. However, the same treatment did not significantly alter the expression of EH1 and GSTP. Overexpression of catalase did not significantly increase EH1, but upregulated BaP-induced expression of microsomal CYP1A1, 1B1, NQO1 and GSTP in the following order: 1A1>NQO1>GSTP>1B1. Overexpression of catalase did not alter the distribution of each of these enzymes in the microsomes. In contrast to our previous report showing lower level of BaP phenols versus BaP diols/diones in the whole-cell, this report demonstrated that the sum of microsomal BaP phenolic metabolites were ~60% greater than that of the BaP diols/diones after exposure of microsomes to BaP. Overexpression of catalase reduced the concentrations of microsomal BaP phenols and diols/diones by ~45 and 95%, respectively. This process enhanced the ratio of BaP phenol versus diol/dione metabolites in a potent manner. Taken together, upregulation of phase II XMEs and CYP1 proteins, but not EH1 in the ER might be the mechanism by which overexpression of catalase reduces the levels of all the BaP metabolites, and

Expression of classical mediators in hearts of rats with hepatic dysfunction.

Science.gov (United States)

Jarkovska, Dagmar; Bludovska, Monika; Mistrova, Eliska; Krizkova, Vera; Kotyzova, Dana; Kubikova, Tereza; Slavikova, Jana; Erek, Sumeyye Nur; Djordjevic, Aleksandar; Chottova Dvorakova, Magdalena

2017-11-01

Liver cirrhosis is associated with impairment of cardiovascular function including alterations of the heart innervation, humoral and nervous dysregulation, changes in systemic circulation and electrophysiological abnormalities. Choline acetyltransferase (ChAT), enzyme forming acetylcholine, tyrosine hydroxylase (TH), and dopamine-β-hydroxylase (DBH), enzymes participating in noradrenaline synthesis, are responsible for the production of classical neurotransmitters, and atrial natriuretic peptide (ANP) is produced by cardiomyocytes. The aim of this study was to evaluate the influence of experimentally induced hepatic dysfunction on the expression of proANP, ChAT, TH, and DBH in the heart. Hepatic dysfunction was induced by application of thioacetamide (TAA) or by ligation of bile duct. Biochemical parameters of hepatic injury and levels of peroxidation in the liver and heart were measured. Liver enzymes measured in the plasma were significantly elevated. Cardiac level of peroxidation was increased in operated but not TAA group animals. In the left atrium of operated rats, the expression of TH and DBH was lower, while expression of ChAT remained unchanged. In TAA group, no significant differences in the expression of the genes compared to controls were observed. Liver injury induced by ligation leads to an imbalance in the intracardiac innervation, which might impair nervous control of the heart.

Protective effect of thymoquinone against lead-induced hepatic toxicity in rats.

Science.gov (United States)

Mabrouk, Aymen; Bel Hadj Salah, Imen; Chaieb, Wafa; Ben Cheikh, Hassen

2016-06-01

Lead (Pb) intoxication is a worldwide health problem which frequently affects the liver. This study was carried out to investigate the potential protective effect of thymoquinone (TQ), the major active ingredient of volatile oil of Nigella sativa seeds, against Pb-induced liver damage. Adult male rats were randomized into four groups: Control group received no treatment, Pb group was exposed to 2000 ppm Pb acetate in drinking water, Pb-TQ group was cotreated with Pb plus TQ (5 mg/kg/day, per orally), and TQ group receiving only TQ. All treatments were applied for 5 weeks. Results indicated that Pb exposure increased hepatic Pb content, damaged hepatic histological structure (necrotic foci, hepatic strands disorganization, hypertrophied hepatocytes, cytoplasmic vacuolization, cytoplasmic loss, chromatin condensation, mononuclear cell infiltration, congestion, centrilobular swelling), and changed liver function investigated by plasma biochemical parameters (AST, ALT, ALP, γ-GT, LDH). Pb treatment also decreased total antioxidant status level and increased lipid peroxidation in the liver. Supplementation with TQ remarkably improved the Pb-induced adverse effects without significantly reducing the metal accumulation in the liver. In conclusion, our results indicate, for the first time, a protective effect of TQ against Pb-induced hepatotoxicity and suggest that this component might be clinically useful in Pb intoxication.

Betaine reduces hepatic lipidosis induced by carbon tetrachloride in Sprague-Dawley rats.

Science.gov (United States)

Junnila, M; Barak, A J; Beckenhauer, H C; Rahko, T

1998-10-01

Carbon tetrachloride-injected rats were given liquid diets with and without betaine for 7 d. Hepatic lipidosis was induced by 4 daily injections of carbon tetrachloride (CCl4). Animals were killed and their livers and blood taken for analysis of betaine, S-adenosylmethionine (SAM), betaine homocysteine methyltransferase (BHMT), triglyceride, alanine aminotransferase and aspartate aminotransferase. Liver samples were also processed and stained for histological examination. Supplemental betaine reduced triglyceride in the liver and centrilobular hepatic lipidosis induced by the CCl4 injections. In both the control and experimental groups receiving betaine, liver betaine, BHMT and SAM were significantly higher than in their respective groups not receiving betaine. This study provides evidence that betaine protects the liver against CCl4-induced lipidosis and may be a useful therapeutic and prophylactic agent in ameliorating the harmful effects of CCl4.

Experimental study of CT perfusion in hepatitis, hepatic fibrosis and early stage of cirrhosis

International Nuclear Information System (INIS)

Guan Sheng; Zhao Weidong; Zhou Kangrong; Peng Weijun; Mao Jian; Tang Feng; Wang Yong; Cao Guang; Sun Fei

2005-01-01

Objective: To investigate the value of CT perfusion in the early diagnosis of hepatic diffuse disease. Methods: Fourteen male Wistar rats of control group and 14 of test group at stages of hepatitis, hepatic fibrosis, hepatic cirrhosis which were induced with diethylnitrosamine (DEN), were studied with CT perfusion respectively. CT perfusion data of different stages were compared and pathologic analysis were performed. Results: Density-time curves of CT perfusion were satisfactory and all perfusion data could be obtained. During the period of hepatitis developing into early stage of hepatic cirrhosis, hepatic artery flow (HAF) trended to increase in test group, mean transmit time (MTT) prolonged obviously, blood flow (BF) and volume (BV) declined. While in control group, HAF declined slightly, MTT, BV and BF increased. Statistic analysis showed the differences of HAF and MTT at different stages between control and test groups were significant (P<0.05 ); the differences of BV and BF between hepatitis and hepatic cirrhosis, hepatic fibrosis and early stage of hepatic cirrhosis in test group were significant (P<0.05), but no significant difference between hepatitis and hepatic fibrosis. The corresponding pathologic changes at stage of hepatitis was swelling of hepatic cells; sinusoids cap illarization and deposition of collagen in the extravascular Disse's spaces were the main changes relating to hepatic blood perfusion at stage of fibrosis and early stage of cirrhosis. Conclusion: The method of CT scan can reflect some changes of hepatic blood perfusion in rats with hepatitis, hepatic fibrosis and early stage of cirrhosis. The data of CT perfusion, especially the changes should be valuable for clinical early diagnosis, treatment and follow-up. (authors)

Beneficial Effects of Phyllanthus amarus Against High Fructose Diet Induced Insulin Resistance and Hepatic Oxidative Stress in Male Wistar Rats.

Science.gov (United States)

Putakala, Mallaiah; Gujjala, Sudhakara; Nukala, Srinivasulu; Desireddy, Saralakumari

2017-11-01

Insulin resistance (IR) is a characteristic feature of obesity, type 2 diabetes mellitus, and cardiovascular diseases. Emerging evidence suggests that the high-fructose consumption is a potential and important factor responsible for the rising incidence of IR. The present study investigates the beneficial effects of aqueous extract of Phyllanthus amarus (PAAE) on IR and oxidative stress in high-fructose (HF) fed male Wistar rats. HF diet (66% of fructose) and PAAE (200 mg/kg body weight/day) were given concurrently to the rats for a period of 60 days. Fructose-fed rats showed weight gain, hyperglycemia, hyperinsulinemia, impaired glucose tolerance, impaired insulin sensitivity, dyslipidemia, hyperleptinemia, and hypoadiponectinemia (P diet significantly ameliorated all these alterations. Regarding hepatic antioxidant status, higher lipid peroxidation and protein oxidation, lower reduced glutathione levels and lower activities of enzymatic antioxidants, and the histopathological changes like mild to severe distortion of the normal architecture as well as the prominence and widening of the liver sinusoids observed in the HF diet-fed rats were significantly prevented by PAAE treatment. These findings indicate that PAAE is beneficial in improving insulin sensitivity and attenuating metabolic syndrome and hepatic oxidative stress in fructose-fed rats.

Biliary excretion of ouabain in isolated perfused rat liver after treatment with microsomal enzyme inducers

International Nuclear Information System (INIS)

Nevasaari, K.; Alakare, B.; Kaerki, N.T.

1976-01-01

The effect of pretreatment with spironolactone, phenobarbital and 3,4-benzpyrene on biliary excretion of ouabain was studied in isolated perfused rat liver system after a single dose of 3 H-ouabain. Spironolactone pretreatment (100 mg/kg intraperitoneally for 4 days) changed the time course of the excretion, thus accelerating the transport of ouabain into the bile. Phenobarbital pretreatment (75 mg/kg intraperitoneally for 4 days) enhanced bile flow and increased biliary excretion of ouabain only after 15 min. At longer time periods the increase in bile flow diluted the bile level of ouabain there being no difference in the amounts excreted into the bile between the treated and untreated groups. 3,4-benzpyrene pretreatment (20 mg/kg intraperitoneally for 4 days) was without efffect on biliary excretion of ouabain. The results suggest that spironolactone differs from phenobarbital in its enhancing effect on biliary excretion of ouabain, possibly through a specific effect on an unknown hepatic transport mechanism. (author)

Characterization of in vitro glucuronidation clearance of a range of drugs in human kidney microsomes: comparison with liver and intestinal glucuronidation and impact of albumin.

Science.gov (United States)

Gill, Katherine L; Houston, J Brian; Galetin, Aleksandra

2012-04-01

Previous studies have shown the importance of the addition of albumin for characterization of hepatic glucuronidation in vitro; however, no reports exist on the effects of albumin on renal or intestinal microsomal glucuronidation assays. This study characterized glucuronidation clearance (CL(int, UGT)) in human kidney, liver, and intestinal microsomes in the presence and absence of bovine serum albumin (BSA) for seven drugs with differential UDP-glucuronosyltransferase (UGT) 1A9 and UGT2B7 specificity, namely, diclofenac, ezetimibe, gemfibrozil, mycophenolic acid, naloxone, propofol, and telmisartan. The impact of renal CL(int, UGT) on accuracy of in vitro-in vivo extrapolation (IVIVE) of glucuronidation clearance was investigated. Inclusion of 1% BSA for acidic drugs and 2% for bases/neutral drugs in incubations was found to be suitable for characterization of CL(int, UGT) in different tissues. Although BSA increased CL(int, UGT) in all tissues, the extent was tissue- and drug-dependent. Scaled CL(int, UGT) in the presence of BSA ranged from 2.22 to 207, 0.439 to 24.4, and 0.292 to 23.8 ml · min(-1) · g tissue(-1) in liver, kidney, and intestinal microsomes. Renal CL(int, UGT) (per gram of tissue) was up to 2-fold higher in comparison with that for liver for UGT1A9 substrates; in contrast, CL(int, UGT) for UGT2B7 substrates represented approximately one-third of hepatic estimates. Scaled renal CL(int, UGT) (in the presence of BSA) was up to 30-fold higher than intestinal glucuronidation for the drugs investigated. Use of in vitro data obtained in the presence of BSA and inclusion of renal clearance improved the IVIVE of glucuronidation clearance, with 50% of drugs predicted within 2-fold of observed values. Characterization and consideration of kidney CL(int, UGT) is particularly important for UGT1A9 substrates.

Açai (Euterpe oleracea Mart. Upregulates Paraoxonase 1 Gene Expression and Activity with Concomitant Reduction of Hepatic Steatosis in High-Fat Diet-Fed Rats

Directory of Open Access Journals (Sweden)

Renata Rebeca Pereira

2016-01-01

Full Text Available Açai (Euterpe oleracea Mart., a fruit from the Amazon region, has emerged as a promising source of polyphenols. Açai consumption has been increasing owing to ascribed health benefits and antioxidant properties; however, its effects on hepatic injury are limited. In this study, we evaluated the antioxidant effect of filtered açai pulp on the expression of paraoxonase (PON isoforms and PON1 activity in rats with nonalcoholic fatty liver disease (NAFLD. The rats were fed a standard AIN-93M (control diet or a high-fat (HF diet containing 25% soy oil and 1% cholesterol with or without açai pulp (2 g/day for 6 weeks. Our results show that açai pulp prevented low-density lipoprotein (LDL oxidation, increased serum and hepatic PON1 activity, and upregulated the expression of PON1 and ApoA-I in the liver. In HF diet-fed rats, treatment with açai pulp attenuated liver damage, reducing fat infiltration and triglyceride (TG content. In rats receiving açai, increased serum PON1 activity was correlated with a reduction in hepatic steatosis and hepatic injury. These findings suggest the use of açai as a potential therapy for liver injuries, supporting the idea that dietary antioxidants are a promising approach to enhance the defensive systems against oxidative stress.

Da-Chaihu-Tang alters the pharmacokinetics of nifedipine in rats and a treatment regimen to avoid this.

Science.gov (United States)

He, Ju-Xiu; Ohno, Kenji; Tang, Jun; Hattori, Masao; Tani, Tadato; Akao, Teruaki

2014-11-01

To investigate the influence of co-administrated Da-Chaihu-Tang (DCT; a traditional Chinese formulation) on the pharmacokinetics of nifedipine, as well as the safe optimal dosing interval to avoid the adverse interactions. A single dose of DCT was administered with nifedipine simultaneously, 2 h before, 30 min before or 30 min after nifedipine administration. Pharmacokinetics of nifedipine with or without DCT were compared. The influences of DCT on nifedipine intestinal mucosal and hepatic metabolism were studied by using rat in-vitro everted jejunal sac model and hepatic microsomes. A simultaneous co-administration of DCT significantly increased the area under concentration-time curve from time zero to infinity (AUC0-inf ) of nifedipine. In-vitro mechanism investigations revealed that DCT inhibited both the intestinal and the hepatic metabolism of nifedipine. Further study on the optimal dosing interval for nifedipine and DCT revealed that administration of DCT 30 min before or after nifedipine did not significantly change the AUC of nifedipine. The bioavailability of nifedipine is significantly increased by a simultaneous oral co-administration of DCT. This increase is caused by the inhibitory effect of DCT on both the intestinal mucosal and the hepatic metabolism of nifedipine. The dose interval between DCT and nifedipine needs to be set for over 30 min to avoid such drug-drug interactions. © 2014 Royal Pharmaceutical Society.

HEPATOPROTECTIVE ACTION OF THYMALINUM AND SUSPENSION OF RED BONE MARROW IN TREATING EXPERIMENTAL TOXIC HEPATITIS OF RATS

Directory of Open Access Journals (Sweden)

E. F. Kulbekov

2014-01-01

Full Text Available Hepatic decompensation problems make it timely to search for the methods of its treatment. Stem cells usage in attempt to restore structures of organs and tissues is a promising direction of researches. However the problem of possible blast-cell transformation slows down studies in this direction. Attempt of thymalinum use as an antitumoral immune system's modulator may be successful and may widen the possibilities of stem cells use in hepatology. On the basis of toxical affection of rats' lever by tetrachloromethane and paracetamol we have studied hepatoprotective activity of thymalinum and suspension of rats' red bone marrow (RBM and a thymalinum + suspension of RBM complex. Hepatoprotective action was estimated by the volume of discharged bile of control group rats which received paracetamol comparing with intact animals. This confirms the absence of reliable hepatotoxical action of paracetamol following the methodology applied. Significant reduction of discharged bile volume of control group rats which received tetrachloromethane comparing with intact animals confirms the successfulness of the formation method of hepatitis model in animals which received tetrachloromethane. The animals which were given tetrachloromethane and thymalinum + suspension of RBM combination had bigger volume of bile discharged than control group animals. Hepatoprotective action tendency of thymalinum + suspension of RBM combination shown before on mice is also true for rats. 

Rat Strain Differences in Susceptibility to Alcohol-Induced Chronic Liver Injury and Hepatic Insulin Resistance

Directory of Open Access Journals (Sweden)

Sarah M. DeNucci

2010-01-01

Full Text Available The finding of more severe steatohepatitis in alcohol fed Long Evans (LE compared with Sprague Dawley (SD and Fisher 344 (FS rats prompted us to determine whether host factors related to alcohol metabolism, inflammation, and insulin/IGF signaling predict proneness to alcohol-mediated liver injury. Adult FS, SD, and LE rats were fed liquid diets containing 0% or 37% (calories ethanol for 8 weeks. Among controls, LE rats had significantly higher ALT and reduced GAPDH relative to SD and FS rats. Among ethanol-fed rats, despite similar blood alcohol levels, LE rats had more pronounced steatohepatitis and fibrosis, higher levels of ALT, DNA damage, pro-inflammatory cytokines, ADH, ALDH, catalase, GFAP, desmin, and collagen expression, and reduced insulin receptor binding relative to FS rats. Ethanol-exposed SD rats had intermediate degrees of steatohepatitis, increased ALT, ADH and profibrogenesis gene expression, and suppressed insulin receptor binding and GAPDH expression, while pro-inflammatory cytokines were similarly increased as in LE rats. Ethanol feeding in FS rats only reduced IL-6, ALDH1–3, CYP2E1, and GAPDH expression in liver. In conclusion, susceptibility to chronic steatohepatitis may be driven by factors related to efficiency of ethanol metabolism and degree to which ethanol exposure causes hepatic insulin resistance and cytokine activation.

The effect of ghee (clarified butter) on serum lipid levels and microsomal lipid peroxidation.

Science.gov (United States)

Sharma, Hari; Zhang, Xiaoying; Dwivedi, Chandradhar

2010-04-01

Ghee, also known as clarified butter, has been utilized for thousands of years in Ayurveda as a therapeutic agent. In ancient India, ghee was the preferred cooking oil. In the last several decades, ghee has been implicated in the increased prevalence of coronary artery disease (CAD) in Asian Indians due to its content of saturated fatty acids and cholesterol and, in heated ghee, cholesterol oxidation products. Our previous research on Sprague-Dawley outbred rats, which serve as a model for the general population, showed no effect of 5 and 10% ghee-supplemented diets on serum cholesterol and triglycerides. However, in Fischer inbred rats, which serve as a model for genetic predisposition to diseases, results of our previous research showed an increase in serum total cholesterol and triglyceride levels when fed a 10% ghee-supplemented diet. In the present study, we investigated the effect of 10% dietary ghee on microsomal lipid peroxidation, as well as serum lipid levels in Fischer inbred rats to assess the effect of ghee on free radical mediated processes that are implicated in many chronic diseases including cardiovascular disease. Results showed that 10% dietary ghee fed for 4 weeks did not have any significant effect on levels of serum total cholesterol, but did increase triglyceride levels in Fischer inbred rats. Ghee at a level of 10% in the diet did not increase liver microsomal lipid peroxidation or liver microsomal lipid peroxide levels. Animal studies have demonstrated many beneficial effects of ghee, including dose-dependent decreases in serum total cholesterol, low density lipoprotein (LDL), very low density lipoprotein (VLDL), and triglycerides; decreased liver total cholesterol, triglycerides, and cholesterol esters; and a lower level of nonenzymatic-induced lipid peroxidation in liver homogenate. Similar results were seen with heated (oxidized) ghee which contains cholesterol oxidation products. A preliminary clinical study showed that high doses of

Characterization of hepatic DNA damage induced in rats by the pyrrolizidine alkaloid monocrotaline

Energy Technology Data Exchange (ETDEWEB)

Petry, T.W.; Bowden, G.T.; Huxtable, R.J.; Sipes, I.G.

1984-04-01

Hepatic DNA damage induced by the pyrrolizidine alkaloid monocrotaline was evaluated following i.p. administration to adult male Sprague-Dawley rats. Animals were treated with various doses ranging upward from 5 mg/kg, and hepatic nuclei were isolated 4 hr later. Hepatic nuclei were used as the DNA source in all experiments. DNA damage was characterized by the alkaline elution technique. A mixture of DNA-DNA interstrand cross-links and DNA-protein cross-links was induced. Following an injection of monocrotaline, 30 mg/kg i.p., DNA-DNA interstrand cross-linking reached a maximum within 12 hr or less and thereafter decreased over a protracted period of time. By 96 hr postadministration, the calculated cross-linking factor was no longer statistically different from zero. No evidence for the induction of DNA single-strand breaks was observed, although the presence of small numbers of DNA single-strand breaks could have been masked by the overwhelming predominance of DNA cross-links. These DNA cross-links may be related to the hepatocarcinogenic, hepatotoxic, and/or antimitotic effects of monocrotaline.

Carbon monoxide-Releasing Molecule-2 (CORM-2 attenuates acute hepatic ischemia reperfusion injury in rats

Directory of Open Access Journals (Sweden)

Zhang Weihui

2010-05-01

Full Text Available Abstract Background Hepatic ischemia-reperfusion injury (I/Ri is a serious complication occurring during liver surgery that may lead to liver failure. Hepatic I/Ri induces formation of reactive oxygen species, hepatocyte apoptosis, and release of pro-inflammatory cytokines, which together causes liver damage and organ dysfunction. A potential strategy to alleviate hepatic I/Ri is to exploit the potent anti-inflammatory and cytoprotective effects of carbon monoxide (CO by application of so-called CO-releasing molecules (CORMs. Here, we assessed whether CO released from CORM-2 protects against hepatic I/Ri in a rat model. Methods Forty male Wistar rats were randomly assigned into four groups (n = 10. Sham group underwent a sham operation and received saline. I/R group underwent hepatic I/R procedure by partial clamping of portal structures to the left and median lobes with a microvascular clip for 60 minutes, yielding ~70% hepatic ischemia and subsequently received saline. CORM-2 group underwent the same procedure and received 8 mg/kg of CORM-2 at time of reperfusion. iCORM-2 group underwent the same procedure and received iCORM-2 (8 mg/kg, which does not release CO. Therapeutic effects of CORM-2 on hepatic I/Ri was assessed by measuring serum damage markers AST and ALT, liver histology score, TUNEL-scoring of apoptotic cells, NFkB-activity in nuclear liver extracts, serum levels of pro-inflammatory cytokines TNF-α and IL-6, and hepatic neutrophil infiltration. Results A single systemic infusion with CORM-2 protected the liver from I/Ri as evidenced by a reduction in serum AST/ALT levels and an improved liver histology score. Treatment with CORM-2 also up-regulated expression of the anti-apoptotic protein Bcl-2, down-regulated caspase-3 activation, and significantly reduced the levels of apoptosis after I/Ri. Furthermore, treatment with CORM-2 significantly inhibited the activity of the pro-inflammatory transcription factor NF-κB as measured in

Kinetics of naphthalene metabolism in target and non-target tissues of rodents and in nasal and airway microsomes from the Rhesus monkey

Energy Technology Data Exchange (ETDEWEB)

Buckpitt, Alan, E-mail: arbuckpitt@ucdavis.edu [Department of Molecular Biosciences, School of Veterinary Medicine, UC Davis, Davis, CA 95616 (United States); Morin, Dexter [Department of Molecular Biosciences, School of Veterinary Medicine, UC Davis, Davis, CA 95616 (United States); Murphy, Shannon; Edwards, Patricia; Van Winkle, Laura [Department of Anatomy, Physiology and Cell Biology, School of Veterinary Medicine, UC Davis, Davis, CA 95616 (United States); Center for Health and the Environment, UC Davis, Davis, CA 95616 United States (United States)

2013-07-15

Naphthalene produces species and cell selective injury to respiratory tract epithelial cells of rodents. In these studies we determined the apparent K{sub m}, V{sub max}, and catalytic efficiency (V{sub max}/K{sub m}) for naphthalene metabolism in microsomal preparations from subcompartments of the respiratory tract of rodents and non-human primates. In tissues with high substrate turnover, major metabolites were derived directly from naphthalene oxide with smaller amounts from conjugates of diol epoxide, diepoxide, and 1,2- and 1,4-naphthoquinones. In some tissues, different enzymes with dissimilar K{sub m} and V{sub max} appeared to metabolize naphthalene. The rank order of V{sub max} (rat olfactory epithelium > mouse olfactory epithelium > murine airways ≫ rat airways) correlated well with tissue susceptibility to naphthalene. The V{sub max} in monkey alveolar subcompartment was 2% that in rat nasal olfactory epithelium. Rates of metabolism in nasal compartments of the monkey were low. The catalytic efficiencies of microsomes from known susceptible tissues/subcompartments are 10 and 250 fold higher than in rat airway and monkey alveolar subcompartments, respectively. Although the strong correlations between catalytic efficiencies and tissue susceptibility suggest that non-human primate tissues are unlikely to generate metabolites at a rate sufficient to produce cellular injury, other studies showing high levels of formation of protein adducts support the need for additional studies. - Highlights: • Naphthalene is metabolized with high catalytic efficiency in susceptible tissue. • Naphthalene is metabolized at low catalytic efficiency in non-susceptible tissue. • Respiratory tissues of the non human primate metabolize naphthalene slowly.

Microsomal UDP-glucuronyltransferase-catalyzed bilirubin diglucuronide formation in human liver

NARCIS (Netherlands)

Peters, W. H.; Jansen, P. L.

1986-01-01

Human liver microsomal bilirubin UDP-glucuronyltransferase catalyzes formation of bilirubin mono- and diglucuronide. KmUDPGA and Vmax of the enzyme are 0.6 mM and 1.69 nmol/mg protein X min. In vitro, bilirubin readily dissolves in the microsomal lipid phase. Taking this into account a Kmbilirubin

Knockout of the aryl hydrocarbon receptor results in distinct hepatic and renal phenotypes in rats and mice

Energy Technology Data Exchange (ETDEWEB)

Harrill, Joshua A. [The Hamner Institute for Health Sciences, Institute for Chemical Safety Sciences, RTP, NC 27709 (United States); Hukkanen, Renee R.; Lawson, Marie; Martin, Greg [The Dow Chemical Company, Midland, MI 48640 (United States); Gilger, Brian [North Carolina State University, College of Veterinary Medicine, Raleigh, NC 27606 (United States); Soldatow, Valerie [University of North Carolina, Department of Environmental Sciences and Engineering, Chapel Hill, NC 27599 (United States); LeCluyse, Edward L. [The Hamner Institute for Health Sciences, Institute for Chemical Safety Sciences, RTP, NC 27709 (United States); Budinsky, Robert A.; Rowlands, J. Craig [The Dow Chemical Company, Midland, MI 48640 (United States); Thomas, Russell S., E-mail: RThomas@thehamner.org [The Hamner Institute for Health Sciences, Institute for Chemical Safety Sciences, RTP, NC 27709 (United States)

2013-10-15

The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor which plays a role in the development of multiple tissues and is activated by a large number of ligands, including 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). In order to examine the roles of the AHR in both normal biological development and response to environmental chemicals, an AHR knockout (AHR-KO) rat model was created and compared with an existing AHR-KO mouse. AHR-KO rats harboring either 2-bp or 29-bp deletion mutation in exon 2 of the AHR were created on the Sprague–Dawley genetic background using zinc-finger nuclease (ZFN) technology. Rats harboring either mutation type lacked expression of AHR protein in the liver. AHR-KO rats were also insensitive to thymic involution, increased hepatic weight and the induction of AHR-responsive genes (Cyp1a1, Cyp1a2, Cyp1b1, Ahrr) following acute exposure to 25 μg/kg TCDD. AHR-KO rats had lower basal expression of transcripts for these genes and also accumulated ∼ 30–45-fold less TCDD in the liver at 7 days post-exposure. In untreated animals, AHR-KO mice, but not AHR-KO rats, had alterations in serum analytes indicative of compromised hepatic function, patent ductus venosus of the liver and persistent hyaloid arteries in the eye. AHR-KO rats, but not AHR-KO mice, displayed pathological alterations to the urinary tract: bilateral renal dilation (hydronephrosis), secondary medullary tubular and uroepithelial degenerative changes and bilateral ureter dilation (hydroureter). The present data indicate that the AHR may play significantly different roles in tissue development and homeostasis and toxicity across rodent species. - Highlights: • An AHR knockout rat was generated on a Sprague–Dawley outbred background. • AHR-KO rats lack expression of AHR protein. • AHR-KO rats are insensitive to TCDD-mediated effects. • Data suggests difference in the role of AHR in tissue development of rats and mice. • Abnormalities in vascular

Knockout of the aryl hydrocarbon receptor results in distinct hepatic and renal phenotypes in rats and mice

International Nuclear Information System (INIS)

Harrill, Joshua A.; Hukkanen, Renee R.; Lawson, Marie; Martin, Greg; Gilger, Brian; Soldatow, Valerie; LeCluyse, Edward L.; Budinsky, Robert A.; Rowlands, J. Craig; Thomas, Russell S.

2013-01-01

The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor which plays a role in the development of multiple tissues and is activated by a large number of ligands, including 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). In order to examine the roles of the AHR in both normal biological development and response to environmental chemicals, an AHR knockout (AHR-KO) rat model was created and compared with an existing AHR-KO mouse. AHR-KO rats harboring either 2-bp or 29-bp deletion mutation in exon 2 of the AHR were created on the Sprague–Dawley genetic background using zinc-finger nuclease (ZFN) technology. Rats harboring either mutation type lacked expression of AHR protein in the liver. AHR-KO rats were also insensitive to thymic involution, increased hepatic weight and the induction of AHR-responsive genes (Cyp1a1, Cyp1a2, Cyp1b1, Ahrr) following acute exposure to 25 μg/kg TCDD. AHR-KO rats had lower basal expression of transcripts for these genes and also accumulated ∼ 30–45-fold less TCDD in the liver at 7 days post-exposure. In untreated animals, AHR-KO mice, but not AHR-KO rats, had alterations in serum analytes indicative of compromised hepatic function, patent ductus venosus of the liver and persistent hyaloid arteries in the eye. AHR-KO rats, but not AHR-KO mice, displayed pathological alterations to the urinary tract: bilateral renal dilation (hydronephrosis), secondary medullary tubular and uroepithelial degenerative changes and bilateral ureter dilation (hydroureter). The present data indicate that the AHR may play significantly different roles in tissue development and homeostasis and toxicity across rodent species. - Highlights: • An AHR knockout rat was generated on a Sprague–Dawley outbred background. • AHR-KO rats lack expression of AHR protein. • AHR-KO rats are insensitive to TCDD-mediated effects. • Data suggests difference in the role of AHR in tissue development of rats and mice. • Abnormalities in vascular

Pathophysiological appraisal of a rat model of total hepatic ischemia with an extracorporeal portosystemic shunt.

Science.gov (United States)

Suzuki, S; Nakamura, S; Sakaguchi, T; Mitsuoka, H; Tsuchiya, Y; Kojima, Y; Konno, H; Baba, S

1998-11-01

Animal models of total hepatic ischemia (THI) and reperfusion injury are restricted by concomitant splanchnic congestion. This study was performed to determine the requirement suitable for an extracorporeal portosystemic shunt (PSS) to maintain the intestinal integrity in a rat model of THI. Using a polyethylene tube (0.86 or 1 mm i.d.), PSS was placed between the mesenteric and jugular veins. Comparison was done between THI models with or without PSS and a partial ischemia model with hepatectomy of the nonischemic lobes. Well-tolerated hepatic ischemic period, portal pressure after 10 min of hepatic ischemia, portal endotoxin levels at 1 h after reperfusion, histological features of the small bowel just before reperfusion, and local jejunal and ileal blood hemoglobin oxygen saturation index (ISO2) were compared among the models. Animals without PSS poorly tolerated 30 min of THI. Animals receiving THI with PSS or partial hepatic ischemia tolerated a longer ischemic period (60 min) with a significantly higher small bowel ISO2, lower portal pressure and endotoxin levels (P tube as well as partial hepatic ischemia were significantly lower than those after THI with PSS using a 0.86-mm i.d. tube. THI with PSS using a 1-mm i.d. tube was strikingly similar to partial hepatic ischemia in the pathophysiological profile during hepatic ischemia. PSS with a tube 1 mm or more in inner diameter offers pathophysiological advantages in experiments on THI and reperfusion. Copyright 1998 Academic Press.

Differential effects of low-fat and high-fat diets on fed-state hepatic triacylglycerol secretion, hepatic fatty acid profiles, and DGAT-1 protein expression in obese-prone Sprague–Dawley rats

Science.gov (United States)

Heden, Timothy D.; Morris, E. Matthew; Kearney, Monica L.; Liu, Tzu-Wen; Park, Young-min; Kanaley, Jill A.; Thyfault, John P.

2015-01-01

The purpose of this study was to compare the effects of short-term low-fat (LF) and high-fat (HF) diets on fed-state hepatic triacylglycerol (TAG) secretion, the content of proteins involved in TAG assembly and secretion, fatty acid oxidation (FAO), and the fatty acid profile of stored TAG. Using selectively bred obese-prone Sprague–Dawley rats, we directly measured fed-state hepatic TAG secretion, using Tyloxapol (a lipoprotein lipase inhibitor) and a standardized oral mixed meal (45% carbohydrate, 40% fat, 15% protein) bolus in animals fed a HF or LF diet for 2 weeks, after which the rats were maintained on their respective diet for 1 week (washout) prior to the liver being excised to measure protein content, FAO, and TAG fatty acid profiles. Hepatic DGAT-1 protein expression was ~27% lower in HF- than in LF-fed animals (p < 0.05); the protein expression of all other molecules was similar in the 2 diets. The fed-state hepatic TAG secretion rate was ~39% lower (p < 0.05) in HF- (4.62 ± 0.18 mmol·h−1) than in LF- (7.60 ± 0.57 mmol·h−1) fed animals. Hepatic TAG content was ~2-fold higher (p < 0.05) in HF- (1.07 ± 0.15 nmol·g−1 tissue) than in LF- (0.50 ± 0.16 nmol·g−1 tissue) fed animals. In addition, the fatty acid profile of liver TAG in HF-fed animals closely resembled the diet, whereas in LF-fed animals, the fatty acid profile consisted of mostly de novo synthesized fatty acids. FAO was not altered by diet. LF and HF diets differentially alter fed-state hepatic TAG secretion, hepatic fatty acid profiles, and DGAT-1 protein expression. PMID:24669989