Source of the arachidonic acid released on stimulation of rat basophilic leukemia cells
Triggering of rat basophilic leukemia cells for histamine secretion is accompanied by arachidonic acid release. The source of this arachidonic acid released after IgE or calcium ionophore A23187 stimulation was studied. The 48-hr culture of the cells with (/sup 14/C)arachidonic acid resulted in labeling of the phospholipids to constant specific activity. After IgE stimulation, 8.8% of the cellular (/sup 14/C)arachidonate was released; this was predominantly from phosphatidylinositol (PI)/phosphatidylserine (PS) (66.3%), less from phosphatidylethanolamine (PE) (25.9%), and minimally from phosphatidylcholine (PC). In contrast, after ionophore stimulation the cells released 16.4% of cellular (/sup 14/C)arachidonate, most of this was from PE (55.4%) followed by about equal amounts from PS/PI and PC (24% and 20%, respectively). Therefore, the source of the released arachidonic acid depends on the stimulus. In contrast, the results are different when the cells are cultured for only 2 hr with (/sup 14/C)arachidonic acid. The label in phospholipids was in PC (44%), PE (38%), and PI/PS (20%); the stimulation of the cells with IgE or ionophore resulted in the release of the (/sup 14/C)arachidonate from PC (81% and 96%, respectively). This suggests the presence of several pools of phospholipids that are labeled at different rates and have variable proximity and/or accessibility to the phospholipase(s) enzyme(s) activated during cell secretion.
- Research Organization:
- National Institutes of Health, Bethesda, MD
- OSTI ID:
- 5009188
- Journal Information:
- J. Immunol.; (United States), Vol. 136:10
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ARACHIDONIC ACID
BIOCHEMICAL REACTION KINETICS
TUMOR CELLS
STIMULATION
BIOLOGICAL PATHWAYS
CARBON 14 COMPOUNDS
CELL CULTURES
ENZYME ACTIVITY
IMMUNOGLOBULINS
LEUKEMIA
MAST CELLS
PHOSPHOLIPIDS
RATS
TRACER TECHNIQUES
ANIMAL CELLS
ANIMALS
CARBOXYLIC ACIDS
CONNECTIVE TISSUE CELLS
DISEASES
ESTERS
GLOBULINS
HEMIC DISEASES
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
LIPIDS
MAMMALS
MONOCARBOXYLIC ACIDS
NEOPLASMS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
PROTEINS
REACTION KINETICS
RODENTS
SOMATIC CELLS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques