125 research outputs found

    Dietary moderately oxidized oil induces expression of fibroblast growth factor 21 in the liver of pigs

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    BACKGROUND: Fibroblast growth factor 21 (FGF21), whose expression is induced by peroxisome proliferator-activated receptor alpha (PPARalpha), has been recently identified as a novel metabolic regulator which plays a crucial role in glucose homeostasis, lipid metabolism, insulin sensitivity and obesity. Previous studies have shown that administration of oxidized fats leads to an activation of PPARalpha in the liver. Therefore, the present study investigated the hypothesis that feeding of oxidized fats causes an induction of FGF21 in the liver. METHODS: Twenty four crossbred pigs were allocated to two groups of 12 pigs each and fed nutritionally adequate diets with either fresh rapeseed oil or oxidized rapeseed oil prepared by heating at a temperature of 175 degrees C for 72 h. RESULTS: In pigs fed the oxidized fat mRNA abundance and protein concentrations of FGF21 in liver were significantly increased (P < 0.05), and the protein concentrations of FGF21 in plasma tended to be increased (P < 0.1) in comparison to control pigs. Moreover, pigs fed the oxidized fat had increased transcript levels of the PPARalpha target genes acyl-CoA oxidase, carnitine palmitoyltransferase-1 and novel organic cation transporter 2 in the liver (P < 0.05), indicative of PPARalpha activation. CONCLUSION: The present study shows for the first time that administration of an oxidized fat induces the expression of FGF21 in the liver, probably mediated by activation of PPARalpha. Induction of FGF21 could be involved in several effects observed in animals administered an oxidized fat

    Asuntos ambientales en la frontera México-Estados Unidos: temas y acciones

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    Dietary moderately oxidized oil activates the Nrf2 signaling pathway in the liver of pigs

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    <p>Abstract</p> <p>Background</p> <p>Previous studies have shown that administration of oxidized oils increases gene expression and activities of various enzymes involved in xenobiotic metabolism and stress response in the liver of rats and guinea pigs. As these genes are controlled by nuclear factor erythroid-derived 2-like 2 (Nrf2), we investigated the hypothesis that feeding of oxidized fats causes an activation of that transcription factor in the liver which in turn activates the expression of antioxidant, cytoprotective and detoxifying genes.</p> <p>Methods</p> <p>Twenty four crossbred pigs were allocated to two groups of 12 pigs each and fed nutritionally adequate diets with either fresh rapeseed oil (fresh fat group) or oxidized rapeseed oil prepared by heating at a temperature of 175°C for 72 h (oxidized fat group).</p> <p>Results</p> <p>After 29 days of feeding, pigs of the oxidized fat group had a markedly increased nuclear concentration of the transcription factor Nrf2 and a higher activity of cellular superoxide dismutase and T4-UDP glucuronosyltransferase in liver than the fresh fat group (<it>P </it>< 0.05). In addition, transcript levels of antioxidant and phase II genes in liver, like superoxide dismutase 1, heme oxygenase 1, glutathione peroxidase 1, thioredoxin reductase 1, microsomal glutathione-S-transferase 1, UDP glucuronosyltransferase 1A1 and NAD(P)H:quinone oxidoreductase 1 in the liver were higher in the oxidized fat group than in the fresh fat group (<it>P </it>< 0.05). Moreover, pigs of the oxidized fat group had an increased hepatic nuclear concentration of the transcription factor NF-κB which is also an important transcription factor mediating cellular stress response.</p> <p>Conclusion</p> <p>The present study shows for the first time that administration of an oxidized fat activates the Nrf2 in the liver of pigs which likely reflects an adaptive mechanism to prevent cellular oxidative damage. Activation of the NF-κB pathway might also contribute to this effect of oxidized fat.</p

    Towards characterizing the adaptive capacity of farmer-managed irrigation systems : learnings from Nepal

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    This work was carried out by the Himalayan Adaptation, Water and Resilience (HI-AWARE) consortium under the Collaborative Adaptation Research Initiative in Africa and Asia (CARIAA) with financial support from the UK Government’s Department for International Development and the International Development Research Centre, Ottawa, Canada. This work was also partially supported by core funds of ICIMOD contributed by the governments of Afghanistan, Australia, Austria, Bangladesh, Bhutan, China, India, Myanmar, Nepal, Norway, Pakistan, Switzerland, and the United Kingdom.Small-scale irrigation systems managed by farmers are facing multiple challenges including competing water demand, climatic variability and change, and socioeconomic transformation. Though the relevant institutions for irrigation management have developed coping and adaptation mechanisms, the intensity and frequency of the changes have weakened their institutional adaptive capacity. Using case examples mostly from Nepal, this paper studies the interconnections between seven key dimensions of adaptive capacity: the five capitals (human, financial, natural, social, and physical), governance, and learning. Long-term adaptation requires harnessing the synergies and tradeoffs between generic adaptive capacity that fosters broader development goals and specific adaptive capacity that strengthens climate-risk management. Measuring and addressing the interrelations among the seven adaptive-capacity dimensions aids in strengthening the long term sustainability of farmer-managed irrigation systems

    Governing a shared hidden resource: A review of governance mechanisms for transboundary groundwater security

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    © 2017 Elsevier B.V. Globally, groundwater is by far the largest store of liquid freshwater, making it a key component of a secure water supply. However, over the past few decades the amount of usable groundwater available around the world has rapidly decreased. This depletion is caused primarily by mismanagement (e.g., overpumping, contamination, and under-regulation), but also by reduced natural recharge due to climate change and urbanization. Management of groundwater resources is particularly challenging for the nearly 600 aquifers that are transboundary, meaning that they extend across international political borders. To understand how governance mechanisms can reduce water insecurity in transboundary groundwater contexts, we review key literature from what we view as the most relevant fields: groundwater management, water security, international water law and international water governance. We then formulate a set of recommendations for improved groundwater governance that can address the specific physical nature of groundwater systems, enhance water security, and apply to transboundary groundwater settings. We argue that groundwater governance in transboundary contexts requires processes that (1) enhance context-specific and flexible international mechanisms; (2) address the perpetual need for groundwater data and information; (3) prioritize the precautionary principle and pollution prevention, in particular; (4) where appropriate, integrate governance of surface and subsurface water and land; and (5) expand institutional capacity, especially of binational or multinational actors
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