Abstract
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.
Citations
Jun 9, 1995·The Journal of Biological Chemistry·A H MerrillD E Vance
Aug 26, 1998·Arteriosclerosis, Thrombosis, and Vascular Biology·R A MemonK R Feingold
Sep 30, 2011·Rapid Communications in Mass Spectrometry : RCM·Yue YuXiao-Hui Chen
Oct 6, 1997·The Journal of Biological Chemistry·C MichelA H Merrill
Nov 24, 1999·The Journal of Biological Chemistry·L A WardenA H Merrill
Mar 1, 1991·The British Journal of Nutrition·C DemignéC Rémésy
Sep 18, 2002·Journal of Lipid Research·Grant M HatchDavid A Bernlohr
Mar 8, 2012·Pflügers Archiv : European journal of physiology·Li LiZhiming Zhu
Aug 9, 2016·Scientific Reports·Haijun HuangLanjuan Li
Aug 11, 1995·The Journal of Biological Chemistry·E R Smith, A H Merrill
Jun 21, 2013·Journal of Neuroinflammation·Ryusuke TakechiJohn C Mamo
Dec 6, 2011·Lipids·Hélène EzannoVincent Rioux
Apr 13, 2000·Biochimica Et Biophysica Acta·N D Ridgway
May 1, 1990·Biochimica Et Biophysica Acta·A H Merrill, D D Jones
Jun 5, 2003·Biochimica Et Biophysica Acta·Kentaro Hanada
Feb 10, 2011·BMC Systems Biology·Shakti GuptaShankar Subramaniam
Jun 22, 2010·Biochimie·Gergana M Deevska, Mariana N Nikolova-Karakashian