Linoleic acid and arachidonic acid metabolism in human peripheral blood leucocytes: comparison with the rat.
Peripheral blood leucocytes from human male volunteers and from male rats were incubated in vitro in the presence of 14C-labelled linoleic acid [( 14C]LA) or 3H-labelled arachidonic acid [( 3H]AA). The time-course of [14C]LA and [3H]AA incorporation into human leucocyte total lipids was maximal at 80-90% of the initial dose within 20-30 min of dosing the cells. Compared with mixed leucocytes, isolated polymorphonuclear leucocytes were only marginally different in the differential incorporation of [14C]LA and [3H]AA into total lipids. In human leucocytes, [14C]LA was incorporated initially into triglycerides but predominantly into phosphatidylcholine thereafter. In the rat, [14C]LA remained as the free acid (63%), with lesser amounts entering the phospholipids (9%), monoglycerides-diglycerides (12%) and triglycerides (less than 1%). Utilization of [14C]LA by the delta 6-desaturase was only a minor route of its metabolism in both human and rat leucocytes. 3H-labelled prostaglandins E2 and F2 alpha accounted for up to 30% of the radioactivity released into the incubation medium from human leucocytes incubated with [3H]AA for 60 min. Stimulation of phagocytosis in the human leucocytes with latex beads or with unopsonized zymosan did not alter the differential incorporation of [14C]LA or [3H]AA into the leucocyte lipid fractions.
D000328:Adult; D000818:Animals; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000097:blood*; D015237:Dinoprost; D015232:Dinoprostone; D044943:Fatty Acid Desaturases / Q000097:blood; D006801:Humans; D066298:In Vitro Techniques; D007962:Leukocytes / Q000378:metabolism*; D019787:Linoleic Acid; D008041:Linoleic Acids / Q000097:blood*; D050602:Linoleoyl-CoA Desaturase; D050356:Lipid Metabolism; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000378:metabolism; D011458:Prostaglandins E / Q000097:blood; D011460:Prostaglandins F / Q000097:blood; D051381:Rats; D011919:Rats, Inbred Strains
D001095:Arachidonic Acids; D008041:Linoleic Acids; D011458:Prostaglandins E; D011460:Prostaglandins F; D016718:Arachidonic Acid; D019787:Linoleic Acid; D015237:Dinoprost; D044943:Fatty Acid Desaturases; D050602:Linoleoyl-CoA Desaturase; D015232:Dinoprostone