Reduced inflammatory response in rats fed fat-rich diets: role of leukotrienes.
The effect of fat-rich diets on the acute inflammatory response was examined. Male Wistar rats aged 21 days were fed, for 6 weeks, with a control diet (4% fat content), or a control diet supplemented with coconut or soybean oils (15% fat content). Carrageenan-induced paw oedema and pleurisy were evaluated. Prostaglandin (PG) E2 and leukotriene (LT) C4/D4 concentrations were determined in the pleural exudate (ELISA). Pleural samples were tested for their effect on cutaneous vascular permeability of control rats and the effect of a LTD4 receptor antagonist (L660-711; 10 mg/kg; i.v.) examined. Relative to controls, rats fed both fat-rich diets presented a significant reduction in protein leakage and oedema formation without affecting the number of migrating leukocytes. Production of LTC4/D4 in pleural exudate was significantly increased from 1.8 +/- 0.2 ng/ml in controls to 2.8 +/- 0.2 and 3.0 +/- 0.3 ng/ml in animals fed coconut and soybean oil enriched diets, respectively, without changes in PGE2 production. The activity of these samples on cutaneous vascular permeability was 50% reduced, returning to control values after treatment of testing animals with a LTD4 receptor antagonist. Rats fed fat-rich diets presented a reduced inflammatory response due, at least in part, to the LTC4/D4 mediated vasoconstrictor effect.
Lopes
L R
LR
Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, Brazil.
Jancar
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S
Curi
R
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Sannomiya
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D000210:Acute-Phase Reaction / Q000139:chemically induced / Q000178:diet therapy* / Q000378:metabolism; D000818:Animals; D002199:Capillary Permeability / Q000187:drug effects; D002351:Carrageenan; D000074263:Coconut Oil; D004041:Dietary Fats / Q000008:administration & dosage*; D015232:Dinoprostone / Q000378:metabolism; D004487:Edema / Q000139:chemically induced / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005122:Exudates and Transudates / Q000378:metabolism; D006614:Hindlimb / Q000187:drug effects; D020024:Leukotriene Antagonists / Q000494:pharmacology; D017997:Leukotriene C4 / Q000378:metabolism*; D017998:Leukotriene D4 / Q000378:metabolism*; D008297:Male; D010938:Plant Oils / Q000008:administration & dosage; D010996:Pleural Effusion / Q000378:metabolism; D010998:Pleurisy / Q000139:chemically induced / Q000378:metabolism; D011422:Propionates / Q000494:pharmacology; D011804:Quinolines / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D012867:Skin / Q000098:blood supply / Q000187:drug effects; D013024:Soybean Oil / Q000008:administration & dosage
D004041:Dietary Fats; D020024:Leukotriene Antagonists; D010938:Plant Oils; D011422:Propionates; D011804:Quinolines; D017997:Leukotriene C4; C059141:verlukast; D017998:Leukotriene D4; D013024:Soybean Oil; D002351:Carrageenan; D015232:Dinoprostone; D000074263:Coconut Oil