Effects of a fish oil diet on the metabolism of endogenous (n-6) and (n-3) fatty acids in rat neutrophils.
The present study was carried out to define more precisely how dietary (n-3) fatty acids mediate leukotriene and phospholipid metabolism in neutrophils. Neutrophils from chow-fed rats did not synthesize detectable levels of LTB5 or 5-hydroxyeicosapentanenoic acid. The ratio of esterified 20:4(n-6)/20:5(n-3) in the phospholipids of neutrophils from rats fed a corn oil/fish oil diet was 4.6. The ratio of LTB4/LTB5 made by these cells was 2.6, thus suggesting that 20:5(n-3) release and/or subsequent metabolism was somewhat more efficient than for 20:4(n-6). When tritiated lyso-platelet activating factor was added to neutrophils from chow-fed rats, it was deactivated primarily by acylation with arachidonic acid. With the fish oil-fed animals both arachidonic acid and 20:5(n-3) were transferred to deactivate lyso-platelet activating factor. Molecular species analysis of the resulting radioactive 1-O-alkyl-2-acyl-sn-glycerol-3-phosphocholine showed that 20:5(n-3) pairs with the same 1-O-alkyl groups and in approximately the same ratio as does arachidonate. Collectively, these studies show that once 20:5(n-3) is incorporated into neutrophil lipids it is metabolized in a similar way as is arachidonate.
Careaga-Houck
M
M
Department of Physiological Chemistry, College of Medicine, Ohio State University, Columbus 43210.
Sprecher
H
H
D000215:Acylation; D000818:Animals; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage / Q000494:pharmacology*; D015118:Eicosapentaenoic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism*; D005395:Fish Oils / Q000008:administration & dosage / Q000494:pharmacology*; D006893:Hydroxyeicosatetraenoic Acids / Q000378:metabolism; D007975:Leukotriene B4 / Q000378:metabolism; D008297:Male; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism*; D010743:Phospholipids / Q000378:metabolism; D010972:Platelet Activating Factor / Q000031:analogs & derivatives / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
D001095:Arachidonic Acids; D004042:Dietary Fats, Unsaturated; D005227:Fatty Acids; D005395:Fish Oils; D006893:Hydroxyeicosatetraenoic Acids; C029271:O-deacetyl platelet activating factor; D010743:Phospholipids; D010972:Platelet Activating Factor; D007975:Leukotriene B4; D016718:Arachidonic Acid; C022022:5-hydroxy-6,8,11,14-eicosatetraenoic acid; C058722:5-hydroxy-6,8,11,14,17-eicosapentaenoic acid; D015118:Eicosapentaenoic Acid