Cytochalasin B augments diacylglycerol levels in stimulated neutrophils

Journal Article · Tue Mar 04 23:00:00 EST 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:6917146

Honeycutt, P J; Niedel, J

Diacylglycerol (DG) has gained wide acceptance as an important second messenger and intracellular activator of protein kinase C, but few studies have directly measured DG levels in cells or tissues. The authors measured the mass of DG in lipid extracts from normal human neutrophils by quantitative conversion of DG to (/sup 32/P) phosphatidic acid using E. coli DG kinase. The chemotactic peptide N-formyl-Met-Leu-Phe (fMLP) stimulated a transient 30% rise in DG that was maximal at 30 to 45 sec and returned to the basal level of 150 picomoles/10/sup 7/ cells by one min. This initial peak was followed by a slower, more prolonged 30% increase in DG that was maximal at 20 min. Cytochalasin B (CB) augments many biological responses of neutrophils to fMLP, including superoxide production and lysosomal enzyme release. CB alone caused no change in basal DG levels, but in the presence of CB, fMLP stimulated a rapid, large, and persistent DG response. DG levels increased to 290% of basal at 5 min with a t1/2 = 45 sec. The DG response to fMLP was maximal at 5 to 10 ..mu..m CB and 1 ..mu..M fMLP. The DG response to optimal fMLP and CB concentrations was decreased 40% by an fMLP antagonist, and no response was elicited by an inactive fMLP analog and CB. Protein kinase C has been implicated in fMLP-stimulated superoxide production and lysosomal enzyme release. These data are consistent with the hypothesis that CB may effect augmentation of biological responses by increasing DG levels.

• Research Organization: Duke Univ. Medical Center, Durham, NC
• OSTI ID: 6917146
• Report Number(s): CONF-8604222-
• Journal Information: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Vol. 45:4; ISSN FEPRA
• Country of Publication: United States
• Language: English

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550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALCOHOLS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
DAYS LIVING RADIOISOTOPES
ENZYMES
FUNGI
GLYCEROL
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
INORGANIC ACIDS
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LEUKOCYTES
LIGHT NUCLEI
MATERIALS
METABOLITES
NEUTROPHILS
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
PEPTIDES
PHOSPHORIC ACID
PHOSPHORUS 32
PHOSPHORUS ISOTOPES
PHOSPHORUS-GROUP TRANSFERASES
PHOSPHOTRANSFERASES
PLANTS
PROTEINS
RADICALS
RADIOISOTOPES
REACTION KINETICS
RESPONSE MODIFYING FACTORS
SECRETION
SUPEROXIDE RADICALS
TRACER TECHNIQUES
TRANSFERASES