Dietary n-3 and n-6 polyunsaturated oils and airway contractility.
Recent reports suggest modulation of chronic obstructive pulmonary disease by dietary polyunsaturated fatty acids. In the present study, we re-examined this possibility by using an established animal model of pulmonary sensitisation. Adult guinea pigs were fed diets supplemented (10% w/w) with either olive, canola or safflower oil for 4 weeks before sensitising with ovalbumin and continuing on various diets for a further 6 week period. Neither the contraction following ovalbumin challenge, nor the responses to histamine, carbachol and various eicosanoid mediators - prostaglandin F(2 alpha), leukotriene C(4), thromboxane mimetic U44619 - of isolated segments of airway tissue were altered (P>0.05, ANOVA) by the dietary lipid treatment. Lipid analysis showed changes in membrane linoleic acid (18:2n-6) and alpha -linolenic acids (alpha 18:3n-3) in lung phospholipids consistent with dietary intakes. However, no significant further desaturation/elongation of these dietary precursors was evident. Ovalbumin induced contraction was fully reversed by the lipoxygenase inhibitor esculetin whilst indomethacin resulted in a slight increase possibly due to the inhibition of bronchodilator prostanoids. Results confirm that under the conditions employed airway function was not influenced by the variable dietary intakes of n-3 and n-6 PUFA.
Abeywardena
M Y
MY
Health Sciences and Nutrition, CSIRO, Kintore Avenue, Adelaide, SA, 5000, Australia. mahinda.abeywardena@hsn.csiro.au
Jablonskis
L T
LT
Head
R J
RJ
D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid / Q000494:pharmacology; D000704:Analysis of Variance; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D001980:Bronchi / Q000187:drug effects*; D002217:Carbachol / Q000494:pharmacology; D002317:Cardiovascular Agents / Q000494:pharmacology; D019587:Dietary Supplements; D015237:Dinoprost / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005227:Fatty Acids / Q000378:metabolism; D005229:Fatty Acids, Monounsaturated / Q000494:pharmacology; D006168:Guinea Pigs; D006632:Histamine / Q000494:pharmacology; D007213:Indomethacin / Q000494:pharmacology; D017997:Leukotriene C4 / Q000494:pharmacology; D019787:Linoleic Acid / Q000494:pharmacology; D050356:Lipid Metabolism; D008168:Lung / Q000378:metabolism; D008297:Male; D000069463:Olive Oil; D010047:Ovalbumin / Q000378:metabolism / Q000494:pharmacology; D010938:Plant Oils / Q000494:pharmacology; D000074262:Rapeseed Oil; D012450:Safflower Oil / Q000494:pharmacology; D013931:Thromboxanes / Q000494:pharmacology; D014468:Umbelliferones / Q000494:pharmacology; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D017962:alpha-Linolenic Acid / Q000494:pharmacology
D000975:Antioxidants; D002317:Cardiovascular Agents; D005227:Fatty Acids; D005229:Fatty Acids, Monounsaturated; D000069463:Olive Oil; D010938:Plant Oils; D000074262:Rapeseed Oil; D013931:Thromboxanes; D014468:Umbelliferones; D014662:Vasoconstrictor Agents; D017962:alpha-Linolenic Acid; D017997:Leukotriene C4; D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; D012450:Safflower Oil; D006632:Histamine; D002217:Carbachol; D010047:Ovalbumin; D019787:Linoleic Acid; D015237:Dinoprost; C007628:esculetin; D007213:Indomethacin