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Dietary fish oil dose‐response effects on ileal phospholipid fatty acids and contractility
Author(s) -
Patten Glen S.,
Adams Michael J.,
Dallimore A.,
Abeywardena Mahinda Y.
Publication year - 2005
Publication title -
lipids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.601
H-Index - 120
eISSN - 1558-9307
pISSN - 0024-4201
DOI - 10.1007/s11745-005-1453-6
Subject(s) - contractility , polyunsaturated fatty acid , endocrinology , medicine , docosapentaenoic acid , fish oil , phospholipid , linoleic acid , prostaglandin , biology , arachidonic acid , chemistry , fatty acid , biochemistry , docosahexaenoic acid , membrane , fishery , fish <actinopterygii> , enzyme
We have reported that dietary fish oil (FO) leads to the incorporation of long‐chain n−3 PUFA into the gut tissue of small animal models, affecting contractility, particularly of rat ileum. This study examined the FO dose response for the incorporation of n−3 PUFA into ileal tissue and how this correlated with in vitro contractility. Groups of ten to twelve 13‐wk‐old Wistar‐Kyoto rats were fed 0, 1, 2.5, and 5% FO‐supplemented diets balanced with sunflower seed oil for 4 wk, after which ileal total phospholipid FA were determined and in vitro contractility assessed. For the total phospholipid fraction, increasing the dietary FO levels led to a significant increase first evident at 1% FO, with a stepwise, nonsaturating six‐fold increase in n−3 PUFA as EPA (20∶5n−3), DPA (docosapentaenoic acid, 22∶5n−3), and DHA, but mainly as DHA (22∶6n−3), replacing the n−6 PUFA linoleic acid (18∶2n−6) and arachidonic acid (20∶4n−6) over the dosage range. There was no difference in KCl‐induced depolarization‐driven contractility. However, a significant increase in receptor‐dependent maximal contractility occurred at 1% FO for carbachol and at 2.5% FO for prostaglandin E 2 , with a concomitant increase in sensitivity for prostaglandin E 2 at 2.5 and 5% FO. These results demonstrate that significant increases in ileal membrane n−3 PUFA occurred at relatively low doses of dietary FO, with differential receptor‐dependent increases in contractility observed for muscarinic and prostanoid agonists.