Dibutyryl Cytidine and Adenosine 3':5'-Cyclic Monophosphates Inhibit A23187-Stimulated Rat Peritoneal Macrophage Leukotriene B4 Synthesis

1988 ◽  
Vol 1 (2) ◽  
pp. 109-114
Author(s):  
G. R. Elliott ◽  
A. P. M. Lauwen ◽  
I. L. Bonta
Keyword(s):  
Peritoneal Macrophage ◽  
Calcium Ionophore ◽  
Peritoneal Macrophages ◽  
Leukotriene B4 ◽  
Calcium Ionophore A23187 ◽  
Intracellular Camp ◽  
Ionophore A23187 ◽  
Eicosanoid Release ◽  
Stable Product

Dibutyryl cytidine and adenosine 3':5'-cyclic monophosphates (db-cCMP and db-cAMP respectively) inhibited the synthesis of thromboxane (TX) B2, the stable product of TXA2, and leukotriene (LT) B4 by 4-day carrageenin-elicited rat peritoneal macrophages stimulated by the calcium ionophore A23187. Incubation of macrophages with dbcAMP, at concentrations inhibiting eicosanoid release, was associated with an increase in intracellular cAMP concentrations. No such increase was seen when db-cCMP was used.

scholarly journals Platelet-activating factor both stimulates and "primes" human polymorphonuclear leukocyte actin filament assembly

Blood ◽  
1987 ◽  
Vol 70 (6) ◽  
pp. 1921-1927 ◽  
Author(s):  
M Shalit ◽  
GA Dabiri ◽  
FS Southwick
Keyword(s):  
Actin Filament ◽  
Polymorphonuclear Leukocyte ◽  
Actin Polymerization ◽  
Platelet Activating Factor ◽  
Calcium Ionophore ◽  
Leukotriene B4 ◽  
Calcium Ionophore A23187 ◽  
Optimal Concentration ◽  
Ionophore A23187 ◽  
Filament Assembly

Abstract The phospholipid inflammatory mediator, platelet-activating factor (PAF), can stimulate polymorphonuclear leukocyte (PMN) chemotaxis. Conversion of cytoplasmic actin from monomers to filaments is associated with PMN motile functions. Using the fluorescent actin filament stain nitrobenzodiaxole phallicidin, we have investigated PAF's effects on human PMN actin polymerization. Concentrations of PAF between 1 x 10(-11) to 1 x 10(-6) mol/L induced actin filament (F- actin) assembly. An optimal concentration of PAF (1–5 x 10(-8) mol/L) induced a significantly lower rise in relative F-actin content (1.72 +/- 0.07 SEM) than an optimal concentration (5 x 10(-7) mol/L) of the chemotactic peptide FMLP (2.21 +/- 0.06). Unlike FMLP (F-actin content: 1.25 +/- 0.04 at five seconds), PAF stimulation was associated with a delay of more than five seconds (1.04 +/- 0.01 at five seconds) before an increase in F-actin could be detected. F-actin concentration reached maximum levels by 30 to 60 seconds. Prolonged stimulation (20 minutes) with PAF was associated with two phases of polymerization and depolymerization. Like FMLP, the initiation of actin filament assembly by PAF required receptor occupancy, this reaction being totally blocked by the PAF receptor inhibitor, SKI 63–441. As evidenced by the lack of inhibition by nordihydroguaiaretic acid (5 to 20 mumol/L), the production of leukotriene B4 was not required for the PAF-induced changes in F-actin. Like FMLP, PAF's ability to stimulate PMN actin polymerization was inhibited by pertussis toxin (.05 to 2.5 micrograms/mL) but not impaired by the addition of EGTA and/or the calcium ionophore A23187. Preincubation with 1 x 10(-11) to 1 x 10(-8) mol/L PAF for 2 to 60 minutes enhanced the rise in F-actin content induced by low concentrations of FMLP (5 x 10(-12) to 1 x 10(-10) mol/L) indicating that this phospholipid was capable of “priming” the PMN actin polymerization response.

scholarly journals Tulathromycin Exerts Proresolving Effects in Bovine Neutrophils by Inhibiting Phospholipases and Altering Leukotriene B4, Prostaglandin E2, and Lipoxin A4Production

2014 ◽  
Vol 58 (8) ◽  
pp. 4298-4307 ◽  
Author(s):  
Carrie D. Fischer ◽  
Stephanie C. Duquette ◽  
Bernard S. Renaux ◽  
Troy D. Feener ◽  
Douglas W. Morck ◽  
...  
Keyword(s):  
Calcium Ionophore ◽  
Leukotriene B4 ◽  
Calcium Ionophore A23187 ◽  
Lipid Signaling ◽  
Prostaglandin E ◽  
Ionophore A23187 ◽  
Proinflammatory Mediators ◽  
Bovine Neutrophils

ABSTRACTThe accumulation of neutrophils and proinflammatory mediators, such as leukotriene B4(LTB4), is a classic marker of inflammatory disease. The clearance of apoptotic neutrophils, inhibition of proinflammatory signaling, and production of proresolving lipids (including lipoxins, such as lipoxin A4[LXA4]) are imperative for resolving inflammation. Tulathromycin (TUL), a macrolide used to treat bovine respiratory disease, confers immunomodulatory benefits via mechanisms that remain unclear. We recently reported the anti-inflammatory properties of TUL in bovine phagocytesin vitroand inMannheimia haemolytica-challenged calves. The findings demonstrated that this system offers a powerful model for investigating novel mechanisms of pharmacological immunomodulation. In the present study, we examined the effects of TUL in a nonbacterial model of pulmonary inflammationin vivoand characterized its effects on lipid signaling. In bronchoalveolar lavage (BAL) fluid samples from calves challenged with zymosan particles (50 mg), treatment with TUL (2.5 mg/kg of body weight) significantly reduced pulmonary levels of LTB4and prostaglandin E2(PGE2). In calcium ionophore (A23187)-stimulated bovine neutrophils, TUL inhibited phospholipase D (PLD), cytosolic phospholipase A2(PLA2) activity, and the release of LTB4. In contrast, TUL promoted the secretion of LXA4in resting and A23187-stimulated neutrophils, while levels of its precursor, 15(S)-hydroxyeicosatetraenoic acid [15(S)-HETE], were significantly lower. These findings indicate that TUL directly modulates lipid signaling by inhibiting the production of proinflammatory eicosanoids and promoting the production of proresolving lipoxins.

scholarly journals The inhibition of neutrophil granule enzyme secretion and chemotaxis by pertussis toxin.

1985 ◽  
Vol 100 (5) ◽  
pp. 1641-1646 ◽  
Author(s):  
E L Becker ◽  
J C Kermode ◽  
P H Naccache ◽  
R Yassin ◽  
M L Marsh ◽  
...  
Keyword(s):  
Pertussis Toxin ◽  
Regulatory Protein ◽  
Calcium Ionophore ◽  
Leukotriene B4 ◽  
Calcium Ionophore A23187 ◽  
Chemotactic Factor ◽  
Target Protein ◽  
Enzyme Secretion ◽  
Ionophore A23187 ◽  
Dependent Inhibition

Pertussis toxin treatment of rabbit peritoneal neutrophils causes a concentration-dependent inhibition of granule enzyme secretion induced by formylmethionyl-leucyl-phenylalanine, C5a, and leukotriene B4. It also inhibits chemotaxis induced by formylmethionyl-leucyl-phenylalanine. The same toxin treatment, however, has no effect on granule enzyme secretion induced by the calcium ionophore A23187 or phorbol 12-myristate 13-acetate. Moreover, pertussis toxin treatment does not affect either the number or affinity of the formylpeptide receptors on the neutrophil nor does it have any effect on the unstimulated levels of cyclic AMP (cAMP) or the transient rise in cAMP induced by chemotactic factor stimulation in these cells. We hypothesize that pertussis toxin, as in other cells, interacts with a GTP binding regulatory protein identical with or analogous to either Ni or transducin which mediates the receptor-induced inhibition or activation of a target protein or proteins required in neutrophil activation. The nature of the target protein is unknown, but it is not the catalytic unit of adenylate cyclase. The target protein acts after binding of chemotactic factor to its receptor in the sequence that leads to the receptor-induced rise in intracellular Ca2+. It does not affect the responses elicited by the direct introduction of calcium into the cells or the activity of protein kinase C.

Development of secretory mechanisms in rat pancreas.

1979 ◽  
Vol 236 (4) ◽  
pp. E446
Author(s):  
S L Werlin ◽  
R J Grand
Keyword(s):  
Calcium Ionophore ◽  
Fetal Tissue ◽  
Calcium Ionophore A23187 ◽  
Intracellular Camp ◽  
Amylase Secretion ◽  
Ionophore A23187 ◽  
Experimental Conditions ◽  
Amylase Release ◽  
Rat Pancreas

Mechanisms and development of secretory function were studied in rat pancreas in vitro. Amylase release from term fetal pancreas was refractory to stimulation by carbamylcholine chloride (carbachol) and cholecystokinin-octapeptide (CCK-OP), but was significantly augmented by calcium ionophore (A23187), DBcAMP, 8-Br-cGMP, and theophylline. The latter agent when combined with either cyclic nucleotide analogue further increased secretory responses. At 1 day and 8 days postnatally, responsiveness to carbachol and CCK-OP had been acquired because amylase secretion stimulated by these agents was brisk and at a level comparable to that found in mature tissue. Increasing extracellular calcium concentrations from 1.23 to 5.28 mM had no effect on basal amylase release in either the fetal or 8-day pancreas. No changes in intracellular cAMP concentrations were found at any age under experimental conditions used. Similarily, in fetal tissue, no changes in cGMP concentrations were found in response to carbachol or A23187. However, at 8 days of age, both agents produced two- to four-fold increases in tissue cGMP levels at 1, 2, and 5 min of incubation. These studies confirm that responsiveness to carbachol and CCK-OP is a maturational process in the pancreas that lags behind the development of intracellular processes involved in stimulus-secretion coupling.

scholarly journals Leukotriene generation by eosinophils.

1982 ◽  
Vol 155 (2) ◽  
pp. 390-402 ◽  
Author(s):  
A Jörg ◽  
W R Henderson ◽  
R C Murphy ◽  
S J Klebanoff
Keyword(s):  
Arachidonic Acid ◽  
Calcium Ionophore ◽  
Leukotriene B4 ◽  
Arachidonic Acid Metabolism ◽  
Calcium Ionophore A23187 ◽  
Eicosatetraenoic Acid ◽  
Gas Chromatography Mass Spectrometry ◽  
Ionophore A23187 ◽  
Lipoxygenase Pathway ◽  
Leukotriene D4

Horse eosinophils purified to greater than 98% generated slow reacting substance (SRS) when incubated with the calcium ionophore A23187. On a per cell basis, eosinophils generated four to five times the SRS produced by similarly treated horse neutrophils. Eosinophil SRS production was inhibited by 5,8,11,14-eicosatetraynoic acid and augmented by indomethacin and arachidonic acid, suggesting that it was a product(s) of the lipoxygenase pathway of arachidonic acid metabolism. Compounds with SRS activity were purified by high-pressure liquid chromatography (HPLC) and identified by ultraviolet spectra, spectral shift on treatment with lipoxygenase, incorporation of [14C]arachidonic acid, gas chromatography-mass spectrometry, and comparison of retention times on HPLC to authentic standards. The eosinophil products characterized were 5-(S), 12-(R)-dihydroxy-6-cis-8, 10-trans-14-cis-eicosatetraenoic acid (leukotriene B4) and its 5-(S), 12-(R)-6-trans and 5-(S), 12-(S)-6-trans isomers, 5-(S)-hydroxy-6-(R)-S-glutathionyl-7,9-trans-11, 14-cis-eicosatetraenoic acid (leukotriene C4) and its 11-trans isomer, and 5-(S)-hydroxy-6-(R)-S-cysteinylglycine-7,9-trans-11,14-cis-eicosatetraenoic acid (leukotriene D4).

Leukotriene B4 production in healthy subjects carrying variants of the arachidonate 5-lipoxygenase-activating protein gene associated with a risk of myocardial infarction

2007 ◽  
Vol 112 (7) ◽  
pp. 411-416 ◽  
Author(s):  
Annette Maznyczka ◽  
Massimo Mangino ◽  
Andrew Whittaker ◽  
Peter Braund ◽  
Tom Palmer ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Healthy Subjects ◽  
Calcium Ionophore ◽  
Population Based ◽  
Leukotriene B4 ◽  
Calcium Ionophore A23187 ◽  
Ionophore A23187 ◽  
Blood Neutrophils ◽  
Ltb4 Production ◽  
Main Regulator

Leukotrienes are implicated in the pathogenesis of coronary artery disease. Recently two haplotypes (HapA and HapB) in the gene encoding ALOX5AP (arachidonate 5-lipoxygenase-activating protein), the main regulator of 5-lipoxygenase, have been associated with a doubling of the risk of myocardial infarction. Studies have also shown that treatment with a leukotriene inhibitor reduces biomarkers of coronary risk in patients carrying HapA, raising the possibility of developing genotype-specific therapy. In the present study, we examined whether carriage of HapA or HapB is associated with increased LTB4 (leukotriene B4) production in healthy subjects. Age- and gender-matched healthy HapA carriers (n=21), HapB carriers (n=20) and non-A/non-B carriers (n=18), with no reported history of cardiovascular disease, were recruited following DNA screening of 1268 subjects from a population-based study. Blood neutrophils were isolated, and LTB4 production was measured in response to stimulation with 1 μmol/l of the calcium ionophore A23187. There was no difference in the mean level for LTB4 production in the three groups (non-A/non-B, 24.9±8.3 ng/106 cells; HapA, 22.2±11.9 ng/106 cells; HapB, 19.8±4.8 ng/106; P=0.14). The findings indicate that if either the HapA or the HapB haplotype of ALOX5AP indeed increases cardiovascular risk, then the mechanism is not simply due to a systematically observable effect of the haplotype on LTB4 production in response to stimulation. The results suggest that knowledge of a patient's haplotype may not provide useful information on the probable clinical response to ALOX5AP inhibitors.

scholarly journals The effect of acute feeding of carnitine, acetyl carnitine and propionyl carnitine on basal and A23187-stimulated eicosanoid release from rat carrageenan-elicited peritoneal macrophages

1990 ◽  
Vol 64 (2) ◽  
pp. 497-503 ◽  
Author(s):  
G. R. Elliott ◽  
A. P. M. Lauwen ◽  
I. L. Bonta
Keyword(s):  
Calcium Ionophore ◽  
Acute Effect ◽  
Peritoneal Macrophages ◽  
Calcium Ionophore A23187 ◽  
Prostaglandin E ◽  
Ionophore A23187 ◽  
Cell Functions ◽  
Prostaglandin F ◽  
Propionyl Carnitine

Little is known about the ability of carnitine to modulate cell functions. As carnitine plays an important role in lipid metabolism we investigated the acute effect of L-carnitine, L-acetyl carnitine and L-propionyl carnitine (300 mg/kg per d; 4 d) on the basal and calcium-ionophore (A23187)-stimulated release of arachidonic acid metabolites from rat carrageenan-elicited peritoneal macrophages. A decrease in the number of peritoneal carrageenan-elicited macrophages was observed after feeding all three compounds. The basal release of prostaglandin E2, 6 keto-prostaglandin F1α and leukotriene B4 was stimulated by all treatments. In contrast, thromboxane B2 production was diminished by feeding carnitine and acetyl carnitine. A23187-stimulated synthesis of 6 keto-prostaglandin F1α and leukotriene B4 was further enhanced by all three compounds. Acetyl carnitine and propionyl carnitine also enhanced thromboxane B2 synthesis. However, no effects on prostaglandin E2 formation were detected. The 6 keto-prostaglandin F1α: thromboxane B2 ratio, calculated from the basal and A23187-stimulated values, was increased by carnitine treatment. In the presence of A23187 there was also an increase in the 6 keto-prostaglandin F1α: leukotriene B4 ratio. We conclude that carnitine, and possibly some of its derivatives, could modify the macrophage component of an inflammation in vivo.

scholarly journals Selective inhibition of human neutrophil functional responsiveness by erbstatin, an inhibitor of tyrosine protein kinase

Blood ◽  
1990 ◽  
Vol 76 (10) ◽  
pp. 2098-2104 ◽  
Author(s):  
PH Naccache ◽  
C Gilbert ◽  
AC Caon ◽  
M Gaudry ◽  
CK Huang ◽  
...  
Keyword(s):  
Platelet Activating Factor ◽  
Calcium Ionophore ◽  
Leukotriene B4 ◽  
Calcium Ionophore A23187 ◽  
Human Neutrophils ◽  
Free Calcium ◽  
Ionophore A23187 ◽  
Functional Responses ◽  
Chemotactic Factors ◽  
Cytoplasmic Free Calcium

Abstract The role of tyrosine kinases in the responses of human neutrophils to chemotactic factors was examined using the recently described inhibitor erbstatin. Pre-incubation with erbstatin decreased the amount of tyrosine phosphorylation induced by the formylated oligopeptide formyl- methionyl-leucyl-phenylalanine (fMet-Leu-Phe) without effecting the binding of [3H]-fMet-Leu-Phe. Erbstatin also dose-dependently inhibited the production of superoxide anion induced by fMet-Leu-Phe and platelet- activating factor, but did not affect the oxidative burst induced by either the calcium ionophore A23187 or the phorbol ester phorbol 12- myristate 13-acetate. Furthermore, erbstatin diminished the cytosolic acidification elicited by fMet-Leu-Phe, platelet-activating factor, and leukotriene B4. In contrast, erbstatin was without effect on the increase in the levels of cytoplasmic free calcium and polymerized actin elicited by fMet-Leu-Phe, C5a, leukotriene B4 and platelet- activating factor, whereas the increase in cytoplasmic free calcium elicited by platelet-derived growth factor was inhibited by erbstatin. In addition, erbstatin affected neither the release of elastase stimulated by these agonists nor the release of beta-glucosaminidase, lysozyme or vitamin B12-binding protein induced by fMet-Leu-Phe. These results indicate that tyrosine protein kinases are involved in the signaling pathways employed by chemotactic factors in the stimulation of selective functional responses (and superoxide production in particular) in human neutrophils.

Sign in / Sign up

Export Citation Format

Share Document