Sphingolipid biosynthesis by rat liver cells: effects of serine, fatty acids and lipoproteins.

Journal Article

The effects of circulating factors that might influence de novo sphingolipid biosynthesis were examined with rat liver cells by following the incorporation of [14C]serine into sphingosine and sphinganine, the predominant long-chain base backbones of hepatic sphingolipids. The rate of long-chain base formation depended on the concentration of [14C]serine in the medium and exhibited saturation kinetics. Long-chain base formation was stimulated by another precursor, palmitic acid, but stearic, oleic, linoleic and linolenic acids were inhibitory. This kinetic behavior indicates that long-chain base formation in liver is affected by the availability of the substrates of the initial enzyme of this pathway, serine palmitoyltransferase. Since liver is also exposed to sphingolipids associated with circulating lipoproteins, the effects of various lipoprotein fractions were determined and each appeared to decrease long-chain base formation. These results suggest that hepatic long-chain base biosynthesis can be stimulated by increases in the circulating levels of the precursors serine and palmitic acid whereas some other fatty acids and lipoproteins decrease the flux through this pathway.

Full Text

Duke Authors

Cited Authors

  • Messmer, TO; Wang, E; Stevens, VL; Merrill, AH

Published Date

  • April 1989

Published In

Volume / Issue

  • 119 / 4

Start / End Page

  • 534 - 538

PubMed ID

  • 2495341

International Standard Serial Number (ISSN)

  • 0022-3166

Language

  • eng

Conference Location

  • United States