Cytoplasmic lipid bodies of human eosinophils. Subcellular isolation and analysis of arachidonate incorporation.
Lipid bodies are non-membrane-bound cytoplasmic inclusions that are prominent in leukocytes engaged in inflammatory responses. As demonstrated by electron microscopic autoradiography, lipid bodies can serve as intracellular sites of 3H-arachidonic acid localization in eosinophils and other cells. To evaluate the role of lipid bodies as stores of esterified arachidonate, subcellular fractionation of lipid-body-rich human eosinophils was used to isolate lipid bodies free of other organelles. In lipid bodies isolated from 3H-arachidonate-labeled eosinophils, 3H-arachidonate was esterified almost totally in glycerolipids, predominantly in classes of phospholipids, including phosphatidyl-inositol and phosphatidylcholine. Lipid bodies, especially in leukocytes participating in inflammation, could represent intracellular sources of esterified arachidonate available for eicosanoid formation.
Weller
P F
PF
Department of Medicine, Harvard Medical School, Boston, Massachusetts.
Monahan-Earley
R A
RA
Dvorak
H F
HF
Dvorak
A M
AM
D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism / Q000648:ultrastructure*; D004804:Eosinophils / Q000378:metabolism / Q000648:ultrastructure*; D006801:Humans; D002479:Inclusion Bodies / Q000378:metabolism / Q000648:ultrastructure*; D050356:Lipid Metabolism; D008854:Microscopy, Electron; D008856:Microscopy, Fluorescence; D013347:Subcellular Fractions / Q000378:metabolism
D001095:Arachidonic Acids; D016718:Arachidonic Acid