Formation of diacyl and alkylacyl glycerophosphocholine in rabbit alveolar macrophages

Journal Article · Sat Aug 01 04:00:00 EDT 1987 · Lipids; (United States)

DOI:https://doi.org/10.1007/BF02537286· OSTI ID:5856820

Sugiura, T; Sekiguchi, N; Nakagawa, Y; Waku, K

The incorporation of various labeled precursors into alkenylacyl, alkylacyl and diacyl phospholipids in rabbit alveolar macrophages was studied. The incorporation rates of the individual precursors were shown to be quite different among the three subclasses of phospholipids. (/sup 3/H)Glycerol, (/sup 14/C)16:0, (/sup 14/C)18:1, (/sup 14/C)18:2 and (/sup 32/P)-orthophosphate were preferentially incorporated into choline glycerophospholipids (CGP), especially into diacyl glycerophosphocholine (GPC), indicating that the de novo synthesis of diacyl GPC is extremely high. Considerable portions of the radioactivities of (/sup 14/C)16:0, (/sup 14/C)18:1, (/sup 14/C)18:2 and (/sup 32/P)orthophosphate were also found in alkylacyl GPC, the incorporation being higher than or comparable to that in the case of diacyl glycerophosphoethanolamine (GPE). We then examined the activities of cholinephosphotransferase and ethanol-aminephosphotransferase, and found that the activity of cholinephosphotransferase was remarkably high in macrophage microsomes compared with that in microsomes from several other tissues. This suggests that diradylglycerols were preferentially utilized by choline-phosphotransferase, which is consistent with the results obtained for intact cells. We confirmed that a considerably higher amount of diacyl GPC as well as alkylacyl GPC was formed through this enzyme reaction with macrophage microsomes than with brain microsomes. The high formation of alkylacyl GPC could be responsible, at least in part, for the accumulation of this unique ether phospholipid, a stored precursor form of platelet-activating factor in macrophages.

• Research Organization: Teikyo Univ., Kanagawa, Japan
• OSTI ID: 5856820
• Journal Information: Lipids; (United States), Journal Name: Lipids; (United States) Vol. 22:8; ISSN LPDSA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMAL CELLS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOSYNTHESIS
BODY
BRAIN
CARBON 14 COMPOUNDS
CELL CONSTITUENTS
CENTRAL NERVOUS SYSTEM
CONNECTIVE TISSUE CELLS
DAYS LIVING RADIOISOTOPES
ENZYME ACTIVITY
ENZYMES
ESTERS
IN VITRO
ISOTOPE APPLICATIONS
ISOTOPES
LABELLED COMPOUNDS
LIGHT NUCLEI
LIPIDS
MACROPHAGES
MAMMALS
MICROSOMES
NERVOUS SYSTEM
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
ORGANOIDS
ORGANS
PHAGOCYTES
PHOSPHOLIPIDS
PHOSPHORUS 32
PHOSPHORUS ISOTOPES
PHOSPHORUS-GROUP TRANSFERASES
PHOSPHOTRANSFERASES
PRECURSOR
RABBITS
RADIOISOTOPES
SOMATIC CELLS
SYNTHESIS
TRACER TECHNIQUES
TRANSFERASES
TRITIUM COMPOUNDS
VERTEBRATES