Endogenous lipids of the earthworm Lumbricus terrestris.
Earthworms (Lumbricus terrestris) were given [1-14C]-labeled palmitic acid by gavage on days 0 and 3, and sacrificed on day 7. The distribution of label among lipid classes indicated that glycerides, sterol esters, cerebrosides, sulfatides, phosphatidylethanolamine, phosphatidylserine and (or) phosphatidylinositol, phosphatidylcholine, and sphingomyelin turn over in, or are synthesized by, the earthworm. Free fatty acids still had the highest specific radioactivity of any lipid class at the end of the experiment. Incorporation of label into sterol and hydrocarbon fractions was insignificant and there was no detectable label incorporated into gangliosides. Phosphatidylethanolamine apparently turned over quite slowly compared with other lipid classes, while the cerebroside fraction became highly labeled. Elongation of palmitic acid to stearate and oxidation to CO2 occurred extensively, but there was no evidence for desaturation.
Laboratory of Molecular Biophysics, National Institute of Environmental Health Sciences, Research Triangle Park, N.C. 27709.
P W
PW
Albro
J T
JT
Corbett
J L
JL
Schroeder
D000818:Animals; D004750:Enteral Nutrition; D050356:Lipid Metabolism; D008055:Lipids / Q000737:chemistry*; D009835:Oligochaeta / Q000737:chemistry* / Q000378:metabolism; D019308:Palmitic Acid; D010169:Palmitic Acids / Q000032:analysis* / Q000378:metabolism
D008055:Lipids; D010169:Palmitic Acids; D019308:Palmitic Acid