The effects of dietary fish oil on inflammation, fibrosis and oxidative stress associated with obstructive renal injury in rats

Authors

  • Jonathan M. Peake,

    Corresponding author
    1. The University of Queensland, School of Human Movement Studies, Brisbane, Australia
    • The University of Queensland, School of Human Movement Studies, St Lucia Qld. 4072, Australia Fax: +61-7-3365-6877
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  • Glenda C. Gobe,

    1. The University of Queensland, Kidney Disease Research Group, Discipline of Medicine, Princess Alexandra Hospital, Brisbane, Australia
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  • Robert G. Fassett,

    1. The University of Queensland, School of Human Movement Studies, Brisbane, Australia
    2. Renal Medicine, Royal Brisbane and Women's and Hospital, Herston, Australia
    3. The University of Queensland, School of Medicine, Brisbane, Australia
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  • Jeff S. Coombes

    1. The University of Queensland, School of Human Movement Studies, Brisbane, Australia
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Abstract

Scope: We examined whether dietary supplementation with fish oil modulates inflammation, fibrosis and oxidative stress following obstructive renal injury.

Methods and results: Three groups of Sprague–Dawley rats (n=16 per group) were fed for 4 wk on normal rat chow (oleic acid), chow containing fish oil (33 g eicosapentaenoic acid and 26 g docosahexaenoic acid per kg diet), or chow containing safflower oil (60 g linoleic acid per kg diet). All diets contained 7% fat. After 4 wk, the rats were further subdivided into four smaller groups (n=4 per group). Unilateral ureteral obstruction was induced in three groups (for 4, 7 and 14 days). The fourth group for each diet did not undergo surgery, and was sacrificed as controls at 14 days. When rats were sacrificed, plasma and portions of the kidneys were removed and frozen; other portions of kidney tissue were fixed and prepared for histology. Compared with normal chow and safflower oil, fish oil attenuated collagen deposition, macrophage infiltration, TGF-β expression, apoptosis, and tissue levels of arachidonic acid, MIP-1α, IL-1β, MCP-1 and leukotriene B4. Compared with normal chow, fish oil increased the expression of HO-1 protein in kidney tissue.

Conclusions: Fish oil intake reduced inflammation, fibrosis and oxidative stress following obstructive renal injury.

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