Early Stimulation of Phosphatidylcholine Biosynthesis During Wallerian Degeneration of Rat Sciatic Nerve

V. Natarajan, Jeffrey K. Yao, Peter J. Dyck, Harald H.O. Schmid

Research output: Contribution to journalArticle

18 Scopus citations

Abstract

Abstract: Phospholipid metabolism was studied in rat sciatic nerve during Wallerian degeneration induced by crush injury. Portions of crushed sciatic nerve, incubated with labeled substrates, showed significantly higher phosphatidylcholine synthesis than normal nerve, prior to any measurable alterations of phospholipid composition. Maximum synthesis occurred 3 days after crush injury, at which time the metabolism of other phospholipids was unchanged. After a rapid decrease in biosynthetic activity, a second phase of enhanced phosphatidylcholine synthesis occurred, beginning 6 days after crush injury. Increased incorporation of [33P]phosphate, [2‐3H]glycerol, and [Me‐14C]‐ choline indicated stimulation of de novo synthesis of phosphatidylcholine 3 days after injury. Neither base exchange reactions nor sequential methylation of ethanolamine phospholipids contributed significantly to phosphatidylcholine synthesis. Assay of certain key enzymes under optimal conditions in subcellular fractions of sciatic nerve revealed higher activities of cholinephosphate cytidyltransferase, choline phosphotransferase, and acyl‐CoA:lysophosphatidylcholine acyltransferase in injured nerve, while choline kinase activity remained unchanged. This indicates that stimulation of phosphatidylcholine synthesis occurs via the cytidine nucleotide pathway, as well as by increased acylation of lysophosphatidylcholine. Although the cause of stimulated phosphatidylcholine synthesis remains unexplained, it is possible that trace amounts of lysophospholipids or other metabolites produced by injury‐enhanced phospholipase activity may be responsible.

Original languageEnglish (US)
Pages (from-to)1419-1428
Number of pages10
JournalJournal of neurochemistry
Volume38
Issue number5
DOIs
StatePublished - May 1982

Keywords

  • Enzymes of phosphatidylcholine synthesis
  • Rat sciatic nerve
  • Subcellular preparations of endoneurium
  • Wallerian degeneration

ASJC Scopus subject areas

  • Biochemistry
  • Cellular and Molecular Neuroscience

Fingerprint Dive into the research topics of 'Early Stimulation of Phosphatidylcholine Biosynthesis During Wallerian Degeneration of Rat Sciatic Nerve'. Together they form a unique fingerprint.

  • Cite this