Phosphatidylcholine synthesis in the rat: The substrate for methylation and regulation by choline
- National Institute of Mental Health, Bethesda, MD (USA)
Two lines of evidence led us to reexamine the possibility that methylation of phosphoethanolamine and its partially methylated derivatives, in addition to methylation of the corresponding phosphatidyl derivatives, plays a role in mammalian phosphatidylcholine biosynthesis: (a) Results obtained by Salerno and Beeler with rat appear to strongly support such a role for methylation of phosphobases; (b) Such reactions have recently been shown to play major roles in phosphatidylcholine synthesis by higher plants. We found that, following continuous labeling of rat liver with L-(methyl-3H)methionine for 10.4 min (intraperitoneal administration) or for 0.75 min (intraportal administration), virtually no 3H was detected in methylated derivatives of phosphoethanolamine, but readily detectable amounts of 3H were present in the base moiety of each methylated derivative of phosphatidylethanolamine. Thus, there was no indication that phospho-base methylation makes a significant contribution. Studies of cultured rat hepatoma cells showed definitively for the first time in a mammalian system that choline deprivation up-regulates the rate of flow of methyl groups originating in methionine into phosphatidylethanolamine and derivatives. Even under these conditions, methylation of phosphoethanolamine bases appeared to play a negligible role.
- OSTI ID:
- 6775014
- Journal Information:
- Lipids; (USA), Vol. 25:3; ISSN 0024-4201
- Country of Publication:
- United States
- Language:
- English
Similar Records
Synthesis of acetylcholine from choline derived from phosphatidylcholine in a human neuronal cell line
Phosphatidylcholine synthesis in castor bean endosperm. I. Metabolism of L-serine. [Ricinus communis]
Related Subjects
AMINES
BIOLOGICAL FUNCTIONS
PHOSPHOLIPIDS
BIOSYNTHESIS
CHOLINE
EXPERIMENTAL NEOPLASMS
LIVER
METHIONINE
METHYLATION
RATS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
TUMOR CELLS
ALCOHOLS
AMINO ACIDS
AMMONIUM COMPOUNDS
ANIMAL CELLS
ANIMALS
BODY
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
DIGESTIVE SYSTEM
DRUGS
ESTERS
FUNCTIONS
GLANDS
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
ISOTOPE APPLICATIONS
LIPIDS
LIPOTROPIC FACTORS
MAMMALS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
ORGANIC SULFUR COMPOUNDS
ORGANS
QUATERNARY COMPOUNDS
RODENTS
SYNTHESIS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques