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Ability of insulin to modulate hepatic glucose production in aging rats is impaired by fat accumulation.

https://arctichealth.org/en/permalink/ahliterature61796
Source
Am J Physiol Endocrinol Metab. 2000 Jun;278(6):E985-91
Publication Type
Article
Date
Jun-2000
Author
G. Gupta
J A Cases
L. She
X H Ma
X M Yang
M. Hu
J. Wu
L. Rossetti
N. Barzilai
Author Affiliation
Department of Medicine, and the Diabetes Research and Training Center, Albert Einstein College of Medicine, New York, New York 10461, USA.
Source
Am J Physiol Endocrinol Metab. 2000 Jun;278(6):E985-91
Date
Jun-2000
Language
English
Publication Type
Article
Keywords
Adipose Tissue
Aging
Animals
Body Composition
Energy intake
Gluconeogenesis
Glucose - biosynthesis
Glycogen - metabolism
Insulin - pharmacology
Leptin - metabolism
Liver - drug effects - metabolism
Male
Rats
Rats, Inbred BN
Rats, Inbred F344
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, P.H.S.
Abstract
Increased total fat mass (FM) and visceral fat (VF) may account in part for age-associated decrease in hepatic insulin action. This study determined whether preventing the changes in body fat distribution abolished this defect throughout aging. We studied the F(1) hybrid of Brown Norway-Fischer 344 rats (n = 29), which we assigned to caloric restriction (CR) or fed ad libitum (AL). CR (55% of the calories consumed by AL) was initiated and used at 2 mo to prevent age-dependent increases in FM and VF. AL rats were studied at 2, 8, and 20 mo; CR rats were studied at 8 and 20 mo. VF and FM remained unchanged throughout aging in CR rats. AL-fed rats at 8 and 20 mo had over fourfold higher FM and VF compared with both CR groups. Insulin clamp studies (3 mU. kg(-1). min(-1) with somatostatin) were performed to assess hepatic insulin sensitivity. Prevention of fat accretion resulted in a marked improvement in insulin action in the suppression of hepatic glucose production (HGP) (6.3 +/- 0.3 and 7.2 +/- 1.2 mg. kg(-1). min(-1) in 8- and 20-mo CR rats vs. 8.3 +/- 0.5 and 10.8 +/- 0.9 mg. kg(-1). min(-1) in 8- and 20-mo AL rats, respectively). The rate of gluconeogenesis (by enrichment of hepatic uridine diphosphate glucose and phosphoenolpyruvate pools by [(14)C]lactate) was unchanged in all groups. The improvement in hepatic insulin action in the CR group was mostly due to effective suppression of glycogenolysis (4.4 +/- 0.3 and 4.9 +/- 0.3 mg. kg(-1). min(-1) in 8- and 20-mo CR rats vs. 5.8 +/- 0.6 and 8.2 +/- 1.0 mg. kg(-1). min(-1) in 8- and 20-mo AL rats, respectively). The results demonstrated the preservation of hepatic insulin action in aging CR rats. Therefore, body fat and its distribution are major determinants of age-associated hepatic insulin resistance.
PubMed ID
10826999 View in PubMed
Less detail

[A comparative evaluation of the effect of different types of sapropel on dynamic liver function in intact rats and in the modelling of toxic hepatitis]

https://arctichealth.org/en/permalink/ahliterature56727
Source
Vopr Kurortol Fizioter Lech Fiz Kult. 1998 Mar-Apr;(2):37-8
Publication Type
Article
Author
D I Kuz'menko
G N Sidorenko
E F Levitskii
B I Laptev
E I Dzhuraeva
Source
Vopr Kurortol Fizioter Lech Fiz Kult. 1998 Mar-Apr;(2):37-8
Language
Russian
Publication Type
Article
Keywords
Animals
Benzopyrans - pharmacology - therapeutic use
Carbon Tetrachloride Poisoning - metabolism - rehabilitation
Comparative Study
Disease Models, Animal
English Abstract
Hepatitis, Toxic - metabolism - rehabilitation
Humic Substances - pharmacology - therapeutic use
Lipid Peroxidation - drug effects
Liver - drug effects - metabolism
Mud Therapy
Rats
Rats, Wistar
Reference Values
Seasons
Siberia
Abstract
A course of silicic sapropel applications compared to calcareous sapropel induced a reversible fall of total lipid concentration in blood serum of intact rats. Sapropels of different kinds and of the same kind but obtained from different depths of the same deposit varied by their ability to correct hepatic function in rats with toxic hepatitis. The highest benefit was registered in application of carbonate sapropels taken from the depth of 1.5-2.5 m.
PubMed ID
9643147 View in PubMed
Less detail

[Age-dependent effects of flavonoids on secretory function of the rat liver]

https://arctichealth.org/en/permalink/ahliterature83213
Source
Fiziol Zh. 2005;51(4):65-9
Publication Type
Article
Date
2005
Author
Babenko N O
Shakhova O H
Source
Fiziol Zh. 2005;51(4):65-9
Date
2005
Language
Ukrainian
Publication Type
Article
Keywords
Aging - drug effects - metabolism
Animals
Bile - chemistry - secretion
Bile Acids and Salts - secretion
Cholesterol - secretion
Dose-Response Relationship, Drug
Flavonoids - isolation & purification - pharmacology
Liver - drug effects - metabolism
Male
Matricaria - chemistry
Rats
Abstract
The effects of the chamomilla recutita (1) flavonoids (chamiloflan) on bilegenesis of the adult and old white rats were investigated. Chamiloflan (20, 40 and 80 mg/kg) induced a dose-dependent increase in the bile flow and bile acid secretion in rats of both age groups. Cholesterol concentration in the liver and bile cholesterol secretion were not changed in the treated adult rats. Chamiloflan increased cholesterol bile secretion and reduced lipid content in the liver of the old rats.
PubMed ID
16201153 View in PubMed
Less detail

[Antioxidant properties of novel preparations--bioflavonoid derivatives and tannins]

https://arctichealth.org/en/permalink/ahliterature56645
Source
Eksp Klin Farmakol. 2001 Mar-Apr;64(2):55-9
Publication Type
Article
Author
L V Iakovleva
O A Gerasimova
I V Karbusheva
A K Ivakhnenko
N D Buniatian
T S Sakharova
Author Affiliation
Central Research Laboratory, Ukrainian Pharmaceutical Academy, ul. Pushkinskaya 53, Kharkov, 310002 Ukraine.
Source
Eksp Klin Farmakol. 2001 Mar-Apr;64(2):55-9
Language
Russian
Publication Type
Article
Keywords
Animals
Antioxidants - pharmacology
Carbon Tetrachloride Poisoning - metabolism
Cell Membrane
Ellagic Acid - pharmacology
English Abstract
Female
Flavonoids - pharmacology
Hepatitis, Toxic - metabolism
Hepatocytes - drug effects - ultrastructure
Lipid Peroxidation - drug effects
Liver - drug effects - metabolism - ultrastructure
Male
Mice
Rats
Tannins - pharmacology
Abstract
New medicinal plant preparations of polyphenol nature, representing the derivatives of bioflavonoids (piflamin) and ellagotannins (altan and ellagic acid) were experimentally studied. The drugs exhibited antioxidant properties, which were manifested by inhibition of a pathological lipid peroxidation, restoration of the functional activity of the antioxidant system components, and stabilization of the hepatocyte membranes.
PubMed ID
11548450 View in PubMed
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Antioxidative stress proteins and their gene expression in brown trout (Salmo trutta) from three rivers with different heavy metal levels.

https://arctichealth.org/en/permalink/ahliterature82460
Source
Comp Biochem Physiol C Toxicol Pharmacol. 2006 Jul;143(3):263-74
Publication Type
Article
Date
Jul-2006
Author
Hansen B H
Rømma S.
Garmo Ø A
Olsvik P A
Andersen R A
Author Affiliation
Norwegian University of Science and Technology (NTNU), Department of Biology, Høgskoleringen 5, N-7491 Trondheim, Norway. bjorn.henrik.hansen@bio.ntnu.no
Source
Comp Biochem Physiol C Toxicol Pharmacol. 2006 Jul;143(3):263-74
Date
Jul-2006
Language
English
Publication Type
Article
Keywords
Animals
Antioxidants - metabolism
Cadmium - analysis - toxicity
Catalase - genetics - metabolism
Copper - analysis - toxicity
Environmental monitoring
Female
Gene Expression
Gills - chemistry - drug effects - metabolism
Glutathione Peroxidase - genetics - metabolism
Kidney - drug effects - metabolism
Liver - drug effects - metabolism
Male
Metallothionein - genetics - metabolism
Norway
Oxidative Stress
RNA, Messenger - metabolism
Rivers
Superoxide Dismutase - genetics - metabolism
Trout - metabolism
Water Pollutants, Chemical - analysis - toxicity
Zinc - analysis - toxicity
Abstract
Three populations of brown trout (Salmo trutta) exposed to different metal levels in their natural environments, were studied with respect to antioxidants metallothionein (MT), superoxide dismutase (SOD) and catalase (CAT) as well as for corresponding mRNA levels. In addition, mRNA levels were studied for glutathione peroxidase (GPx) and glutathione reductase (GR). The Cd/Zn-exposed trout (Naustebekken River) had higher accumulated levels of Cd, Cu and Zn in gills, and higher levels of MT (both protein and mRNA) in liver and kidney as well as in gills compared to the Cu-exposed trout (Rugla River) and trout from an uncontaminated reference river (Stribekken River). Less MT found in the Cu-exposed trout may increase susceptibility to oxidative stress, but no higher levels of antioxidant mRNAs were found in gills of these trouts. The data indicated that chronic exposures of brown trout to Cd, Zn and/or Cu did not involve maintenance of high activities of SOD and CAT enzymes in gills, although SOD mRNA levels were higher in the Cd/Zn-exposed trout. In livers, mRNA levels of SOD, CAT and GPx were higher in the metal-exposed trout, but in the case of GR this was only seen in kidneys of Cd/Zn-exposed trout. However, both metal-exposed groups had higher activities of SOD enzyme in liver compared to the unexposed reference trout, and CAT activity was found to be higher in kidneys of Cu-exposed trout. The Cu-exposed trout did not seem to rely on MT production to avoid Cu toxicity in gills, but rather by keeping the Cu uptake at a low level. A coordinated expression of different stress genes may also be important in chronic metal exposure. It may be concluded that the observed metal effects relies on acclimation rather than on genetic adaptation in the metal exposed populations.
PubMed ID
16616685 View in PubMed
Less detail

Application of a yeast estrogen screen in non-biomarker species Varicorhinus barbatulus fish with two estrogen receptor subtypes to assess xenoestrogens.

https://arctichealth.org/en/permalink/ahliterature165448
Source
Toxicol In Vitro. 2007 Jun;21(4):604-12
Publication Type
Article
Date
Jun-2007
Author
Keng-Yen Fu
Chung-Yuan Chen
Whei-Meih Chang
Author Affiliation
Institute of Environmental Engineering, National Chiao Tung University, Hsinchu 300, Taiwan, ROC.
Source
Toxicol In Vitro. 2007 Jun;21(4):604-12
Date
Jun-2007
Language
English
Publication Type
Article
Keywords
Animals
Cloning, Molecular
Cyprinidae - physiology
Environmental Pollutants - toxicity
Estrogen Receptor alpha - drug effects - genetics - metabolism
Estrogen Receptor beta - drug effects - genetics - metabolism
Estrogens, Non-Steroidal - toxicity
Female
Humans
Ligands
Liver - drug effects - metabolism
Oncorhynchus mykiss
Receptors, Estrogen - drug effects - genetics - metabolism
Transcriptional Activation - genetics
Xenobiotics - toxicity
Yeasts - genetics - metabolism
Abstract
Xenoestrogens can interfere with normal estrogen signaling by competitively binding to the estrogen receptor (ER) and activating transcription of target genes. In this study, we cloned the estrogen receptor alpha (vbERalpha) and beta 2 (vbERbeta2) genes from liver of the indigenous Taiwanese cyprinid fish Varicorhinus barbatulus and tested the direct impact of several xenoestrogens on these ERs. Transcriptional activity of xenoestrogens was measured by the enzymatic activity of estrogen responsive element (ERE)-containing beta-galactosidase in a yeast reporter system. The xenoestrogens tested were phenol derivatives, DDT-related substances, phthalic acid esters, and polychlorinated biphenyls, with 17beta-estradiol (E2) as a subjective standard. The phenol derivatives [4-nonylphenol (4-NP), 4-t-octylphenol (4-t-OP) and bisphenol A (BPA)] exhibited significant dose-dependent responses in both ligand potency and ligand efficiency. Consistent with yeast assays using human or rainbow trout ERs, we observed a general subtype preference in that vbERalpha displayed higher relative potencies and efficiencies than vbERbeta2, although our assays induced a stronger response for xenoestrogens than did human or trout ERs. Whereas 4-NP and 4-t-OP have similar EC50 values relative to E2 for both ER subtypes, the strong estrogenic response of BPA markedly differentiates vbERalpha from vbERbeta2, suggesting possible species-specific BPA sensitivity. We report that the ameliorative yeast tool is readily applicable for indigenous wildlife studies of the bio-toxic influence of xenoestrogens with wildlife-specific estrogen receptors.
PubMed ID
17258427 View in PubMed
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Arctic berry extracts target the gut-liver axis to alleviate metabolic endotoxaemia, insulin resistance and hepatic steatosis in diet-induced obese mice.

https://arctichealth.org/en/permalink/ahliterature297424
Source
Diabetologia. 2018 04; 61(4):919-931
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Date
04-2018
Author
Fernando F Anhê
Thibault V Varin
Mélanie Le Barz
Geneviève Pilon
Stéphanie Dudonné
Jocelyn Trottier
Philippe St-Pierre
Cory S Harris
Michel Lucas
Mélanie Lemire
Éric Dewailly
Olivier Barbier
Yves Desjardins
Denis Roy
André Marette
Author Affiliation
Department of Medicine, Faculty of Medicine, Cardiology Axis of the Québec Heart and Lung Institute, Laval University, Bureau Y4340, Québec City, QC, G1V 4G5, Canada.
Source
Diabetologia. 2018 04; 61(4):919-931
Date
04-2018
Language
English
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Keywords
Animals
C-Peptide - blood
Diet, High-Fat
Endotoxemia - metabolism
Fatty Liver - drug therapy - metabolism
Fruit - chemistry
Glucose - metabolism
Homeostasis
Insulin - blood - metabolism
Insulin Resistance
Intestines - drug effects
Liver - drug effects - metabolism
Male
Mice
Mice, Inbred C57BL
Mice, Obese
Obesity - metabolism
Plant Extracts - pharmacology
RNA, Ribosomal, 16S - genetics
Time Factors
Abstract
There is growing evidence that fruit polyphenols exert beneficial effects on the metabolic syndrome, but the underlying mechanisms remain poorly understood. In the present study, we aimed to analyse the effects of polyphenolic extracts from five types of Arctic berries in a model of diet-induced obesity.
Male C57BL/6 J mice were fed a high-fat/high-sucrose (HFHS) diet and orally treated with extracts of bog blueberry (BBE), cloudberry (CLE), crowberry (CRE), alpine bearberry (ABE), lingonberry (LGE) or vehicle (HFHS) for 8 weeks. An additional group of standard-chow-fed, vehicle-treated mice was included as a reference control for diet-induced obesity. OGTTs and insulin tolerance tests were conducted, and both plasma insulin and C-peptide were assessed throughout the OGTT. Quantitative PCR, western blot analysis and ELISAs were used to assess enterohepatic immunometabolic features. Faecal DNA was extracted and 16S rRNA gene-based analysis was used to profile the gut microbiota.
Treatment with CLE, ABE and LGE, but not with BBE or CRE, prevented both fasting hyperinsulinaemia (mean ± SEM [pmol/l]: chow 67.2?±?12.3, HFHS 153.9?±?19.3, BBE 114.4?±?14.3, CLE 82.5?±?13.0, CRE 152.3?±?24.4, ABE 90.6?±?18.0, LGE 95.4?±?10.5) and postprandial hyperinsulinaemia (mean ± SEM AUC [pmol/l?×?min]: chow 14.3?±?1.4, HFHS 31.4?±?3.1, BBE 27.2?±?4.0, CLE 17.7?±?2.2, CRE 32.6?±?6.3, ABE 22.7?±?18.0, LGE 23.9?±?2.5). None of the berry extracts affected C-peptide levels or body weight gain. Levels of hepatic serine phosphorylated Akt were 1.6-, 1.5- and 1.2-fold higher with CLE, ABE and LGE treatment, respectively, and hepatic carcinoembryonic antigen-related cell adhesion molecule (CEACAM)-1 tyrosine phosphorylation was 0.6-, 0.7- and 0.9-fold increased in these mice vs vehicle-treated, HFHS-fed mice. These changes were associated with reduced liver triacylglycerol deposition, lower circulating endotoxins, alleviated hepatic and intestinal inflammation, and major gut microbial alterations (e.g. bloom of Akkermansia muciniphila, Turicibacter and Oscillibacter) in CLE-, ABE- and LGE-treated mice.
Our findings reveal novel mechanisms by which polyphenolic extracts from ABE, LGE and especially CLE target the gut-liver axis to protect diet-induced obese mice against metabolic endotoxaemia, insulin resistance and hepatic steatosis, which importantly improves hepatic insulin clearance. These results support the potential benefits of these Arctic berries and their integration into health programmes to help attenuate obesity-related chronic inflammation and metabolic disorders.
All raw sequences have been deposited in the public European Nucleotide Archive server under accession number PRJEB19783 ( https://www.ebi.ac.uk/ena/data/view/PRJEB19783 ).
PubMed ID
29270816 View in PubMed
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Arctic marine fish 'biotransformation toxicity' model for ecological risk assessment.

https://arctichealth.org/en/permalink/ahliterature302956
Source
Mar Pollut Bull. 2019 May; 142:408-418
Publication Type
Journal Article
Date
May-2019
Author
Faisal Fahd
Brian Veitch
Faisal Khan
Author Affiliation
Centre for Risk, Integrity and Safety Engineering (C-RISE), Faculty of Engineering and Applied Science, Memorial University of Newfoundland, St. John's, NL A1B 3X5, Canada.
Source
Mar Pollut Bull. 2019 May; 142:408-418
Date
May-2019
Language
English
Publication Type
Journal Article
Keywords
Animals
Arctic Regions
Bayes Theorem
Biotransformation
Ecotoxicology - methods
Environmental Biomarkers
Enzymes - metabolism
Gadiformes - metabolism - physiology
Liver - drug effects - metabolism
Models, Theoretical
Petroleum Pollution - adverse effects
Polycyclic Aromatic Hydrocarbons - pharmacokinetics - toxicity
Risk assessment
Seasons
Water Pollutants, Chemical - pharmacokinetics - toxicity
Xenobiotics - pharmacokinetics - toxicity
Abstract
Oil and gas exploration and marine transport in the Arctic region have put the focus on the ecological risk of the possibly exposed organisms. In the present study, the impacts of sea ice, extreme light regime, various polar region-specific physiological characteristics in polar cod (Boreogadus saida) and their effects on xenobiotic distribution and metabolism are studied. A Bayesian belief network is used to model individual fish toxicity. The enzyme activity in the fish liver and other pertinent organs is used as a proxy for cellular damage and repair and is subsequently linked to toxicity in polar cod. Seasonal baseline variation in enzyme production is also taken into consideration. The model estimates the probability of exposure concentration to cause cytotoxicity and circumvents the need to use the traditionally obtained No Observed Effect Concentration (NOEC). Instead, it uses biotransformation enzyme activity as a basis to estimate the probability of individual cell damages.
PubMed ID
31232318 View in PubMed
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[Changes in lipid peroxidation in the liver tissue and blood serum of rats with chronic toxic hepatitis under the influence of naftusia mineral water]

https://arctichealth.org/en/permalink/ahliterature56921
Source
Vopr Kurortol Fizioter Lech Fiz Kult. 1988 Jul-Aug;(4):57-9
Publication Type
Article

84 records – page 1 of 9.