Release of platelet-activating factor and the metabolism of leukotriene B4 by the human neutrophil when studied in a cell superfusion model

Journal Article · Fri Dec 01 04:00:00 EST 1989 · Journal of Immunology; (USA)

OSTI ID:5031620

Cluzel, M; Undem, B J; Chilton, F H ^[1]

---

1. Johns Hopkins Univ. School of Medicine, Baltimore, MD (USA)

Stimulated human neutrophils are known to synthesize large quantities of 1-0-alkyl-2-acetyl-sn-glycero-3-phosphocholine (PAF) and 5,12-dihydroxy-6,14-cis-8,10-trans-transeicosatetraenoic acid (LTB4). However, in an isolated cell suspension the majority of synthesized PAF appears to remain cell associated. In addition, LTB4 is rapidly metabolized to an omega-oxidation product. Experiments were designed to test the hypothesis that the degree of association of PAF with the neutrophils and the metabolism of LTB4 by the neutrophils is a result of the in vitro condition used during cell activation. Here we have compared in paired experiments ionophore A23187-induced production of PAF and LTB4 by human neutrophils in a concentrated cell suspension, a diluted cell suspension and in a system in which the cells are placed on a matrix and superfused with buffer at a constant flow rate (dynamic system). There was little difference in the amount of PAF synthesized in the concentrated cell suspension and the dynamic system. However, less PAF was produced by neutrophils in the dilution system. The percent of PAF released was consistently greater in the dynamic and dilution systems than in the concentrated cell suspension. For example, more than 40% of PAF measured by incorporation of (3H)acetate or gas chromatography/mass spectrometry was released in the dynamic system and dilution systems. In contrast, less than 15% of the PAF synthesized was released from the cells in the concentrated cell suspension. 1-0-Hexadecyl-2-acetyl-3-GPC was primarily released from the neutrophils. By contrast both 1-0-hexadecyl and 1-0-octadecyl linked species of PAF were found within the cells. Exogenous PAF added to neutrophils in the dynamic or dilution systems was taken up and metabolized at a significantly lower rate than that added to cells in the concentrated cell suspensions.

• OSTI ID: 5031620
• Journal Information: Journal of Immunology; (USA), Journal Name: Journal of Immunology; (USA) Vol. 143:11; ISSN JOIMA; ISSN 0022-1767
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ACETATES
ANIMALS
BIOLOGICAL MATERIALS
BIOLOGICAL MODELS
BLOOD
BLOOD CELLS
BLOOD COAGULATION FACTORS
BODY FLUIDS
CARBOXYLIC ACID SALTS
CHROMATOGRAPHY
COAGULANTS
DISPERSIONS
DRUGS
GAS CHROMATOGRAPHY
HEMATOLOGIC AGENTS
HYDROGEN COMPOUNDS
ISOTOPE APPLICATIONS
LEUKOCYTES
MAMMALS
MAN
MASS SPECTROSCOPY
MATERIALS
METABOLISM
NEUTROPHILS
ORGANIC COMPOUNDS
PRIMATES
PROSTAGLANDINS
PROTEINS
SECRETION
SEPARATION PROCESSES
SPECTROSCOPY
SUSPENSIONS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES