title: Unique phospholipid metabolism in mouse heart in response to dietary docosahexaenoic or alpha-linolenic acids.
abstract: Diet and fatty acid metabolism interact in yet unknown ways to modulate membrane fatty acid composition and certain cellular functions. For example, dietary precursors or metabolic products of n-3 fatty acid metabolism differ in their ability to modify specific membrane components. In the present study, the effect of dietary 22:6n-3 or its metabolic precursor, 18:3n-3, on the selective accumulation of 22:6n-3 by heart was investigated. The mass and fatty acid compositions of individual phospholipids (PL) in heart and liver were quantified in mice fed either 22:6n-3 (from crocodile oil) or 18:3n-3 (from soybean oil) for 13 wk. This study was conducted to determine if the selective accumulation of 22:6n-3 in heart was due to the incorporation of 22:6n-3 into cardiolipin (CL), a PL most prevalent in heart and known to accumulate 22:6n-3. Although heart was significantly enriched with 22:6n-3 relative to liver, the accumulation of 22:6n-3 by CL in heart could not quantitatively account for this difference. CL from heart did accumulate 22:6n-3, but only in mice fed preformed 22:6n-3. Diets rich in non-22:6n-3 fatty acids result in a fatty acid composition of phosphatidylcholine (PC) in heart that is unusually enriched with 22:6n-3. In this study, the mass of PC in heart was positively correlated with the enrichment of 22:6n-3 into PC. The increased mass of PC was coincident with a decrease in the mass of phosphatidylethanolamine, suggesting that 22:6n-3 induced PC synthesis by increasing phosphatidylethanolamine-N-methyltransferase activity in the heart.
authors.affiliation: Department of Food Science and Technology, 1 Shields Ave., University of California at Davis, Davis, CA 95616, USA. smwatkins@ucdavis.edu
authors.forename: S M
authors.initials: SM
authors.lastname: Watkins
authors.forename: T Y
authors.initials: TY
authors.lastname: Lin
authors.forename: R M
authors.initials: RM
authors.lastname: Davis
authors.forename: J R
authors.initials: JR
authors.lastname: Ching
authors.forename: E J
authors.initials: EJ
authors.lastname: DePeters
authors.forename: G M
authors.initials: GM
authors.lastname: Halpern
authors.forename: R L
authors.initials: RL
authors.lastname: Walzem
authors.forename: J B
authors.initials: JB
authors.lastname: German
mesh_terms: D000489:Alligators and Crocodiles; D000818:Animals; D002308:Cardiolipins / Q000378:metabolism; D004042:Dietary Fats, Unsaturated / Q000494:pharmacology*; D004281:Docosahexaenoic Acids / Q000494:pharmacology*; D005227:Fatty Acids / Q000032:analysis; D008055:Lipids / Q000032:analysis; D008099:Liver / Q000737:chemistry / Q000378:metabolism; D051379:Mice; D009206:Myocardium / Q000737:chemistry / Q000378:metabolism*; D010713:Phosphatidylcholines / Q000032:analysis; D010714:Phosphatidylethanolamines / Q000032:analysis; D010743:Phospholipids / Q000032:analysis / Q000378:metabolism*; D013024:Soybean Oil / Q000494:pharmacology; D017962:alpha-Linolenic Acid / Q000494:pharmacology*
chemical_list: D002308:Cardiolipins; D004042:Dietary Fats, Unsaturated; D005227:Fatty Acids; D008055:Lipids; D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; D010743:Phospholipids; D017962:alpha-Linolenic Acid; D004281:Docosahexaenoic Acids; D013024:Soybean Oil