Unique phospholipid metabolism in mouse heart in response to dietary docosahexaenoic or alpha-linolenic acids.
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.
Watkins
S M
SM
Department of Food Science and Technology, 1 Shields Ave., University of California at Davis, Davis, CA 95616, USA. smwatkins@ucdavis.edu
Lin
T Y
TY
Davis
R M
RM
Ching
J R
JR
DePeters
E J
EJ
Halpern
G M
GM
Walzem
R L
RL
German
J B
JB
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*
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