Inositol phosphate formation in chemotactic peptide-activated neutrophils obtained from normal and schizophrenic subjects

1989 ◽  
Vol 17 (4) ◽  
pp. 709-710 ◽  
Author(s):  
INDRAJIT DAS ◽  
JACQUELINE DE BELLEROCHE ◽  
ANTHONY G. JOLLEY ◽  
MOHAMMED A. ESSALI ◽  
STEVEN R. HIRSCH
Keyword(s):  
Inositol Phosphate ◽  
Chemotactic Peptide ◽  
Activated Neutrophils

scholarly journals Inositol phosphate formation in fMet-Leu-Phe-stimulated human neutrophils does not require an increase in the cytosolic free Ca2+ concentration

1985 ◽  
Vol 229 (2) ◽  
pp. 361-367 ◽  
Author(s):  
F Di Virgilio ◽  
L M Vicentini ◽  
S Treves ◽  
G Riz ◽  
T Pozzan
Keyword(s):  
Time Course ◽  
Inositol Phosphates ◽  
Inositol Phosphate ◽  
Inositol Trisphosphate ◽  
Human Neutrophils ◽  
Chemotactic Peptide

The accumulation of inositol phosphates in myo-[3H]inositol-labelled human neutrophils stimulated with the chemotactic peptide fMet-Leu-Phe was measured. The challenge with the chemotactic peptide caused the generation of inositol monophosphate (InsP), inositol bisphosphate (InsP2) and inositol trisphosphate (InsP3). The formation of the three inositol phosphates followed a differential time course: InsP3 accumulated very rapidly and transiently, whereas InsP increased steadily for more than 2 min. Inositol phosphate formation was only partially decreased by procedures which prevented the fMet-Leu-Phe-dependent increase of cytosolic free Ca2+ concentration.

Resting and stimulated cytosolic free calcium levels in neutrophils from patients with Bartter's syndrome

1987 ◽  
Vol 72 (4) ◽  
pp. 483-488 ◽  
Author(s):  
Francesco Di Virgilio ◽  
Lorenzo Calò ◽  
Salvatore Cantaro ◽  
Silvana Favaro ◽  
Antonio Piccoli ◽  
...  
Keyword(s):  
Free Calcium ◽  
Healthy Controls ◽  
Bartter’S Syndrome ◽  
Bartter's Syndrome ◽  
Chemotactic Peptide ◽  
Cytosolic Free Calcium ◽  
Fluorescent Indicator ◽  
Activated Neutrophils ◽  
Normal Controls

1. Cytosolic free calcium concentrations ([a2+]i) were measured in resting and chemotactic peptide-activated neutrophils from eight patients with Bartter's syndrome and compared with levels determined in neutrophils isolated from healthy controls. 2. [Ca2+]i was measured with the intracellular trappable fluorescent indicator Quin2. The synthetic tripeptide formylmethionyl-leucyl-phenylalanine (fMet-Leu-Phe) was used as a stimulant. 3. No difference was found in resting [Ca2+]i between neutrophils from normal controls and those from patients with Bartter's syndrome. 4. On the contrary increases in [Ca2+]i stimulated by fMet-Leu-Phe concentrations higher than 10−8 mol/l were significantly less in neutrophils from patients with Bartter's syndrome. 5. It is suggested that neutrophils from patients affected by Bartter's syndrome exhibit an intrinsic anomaly in the mechanism responsible for intracellular Ca2+ mobilization.

Anaphylatoxin and chemotactic peptide

2006 ◽  
pp. S15-S16
Author(s):  
S P H Alexander ◽  
A Mathie ◽  
J A Peters
Keyword(s):  
Chemotactic Peptide

Localization of Abscess with an Iodinated Synthetic Chemotactic Peptide

1982 ◽  
Vol 21 (03) ◽  
pp. 110-113 ◽  
Author(s):  
M.-S. Jiang ◽  
E. G. Corley ◽  
H. N. Wagner ◽  
M.-F. Tsan
Keyword(s):  
Chemotactic Peptide ◽  
Hatte Eine

N-Formyl Nle-Leu-Phe-Nle-Tyr-Lys ist ein wirksames synthetisches chemotaktisches Peptid (CP), welches sich mit hoher Affinität an chemotaktische Rezeptoren von neutrophilen Leukozyten bindet. Da das Peptid einen Tyrosin-Anteil enthält, kann es leicht mit radioaktivem Jod markiert werden. In dieser Arbeit haben wir die Möglichkeit der Abszeß-Lokalisierung durch intravenöse Gabe von radioaktivem CP untersucht. Das Peptid wurde nach der Chloramin-T-Methode mit 125J markiert und mittels Bio-Gel-P-2-Chromatographie gereinigt. Die endgültige Lösung hatte eine Reinheit von 88.5 ± 3.8% (n = 6) und eine spezifische Aktivität von 600-800 Ci/mM. Das jodierte CP zeigte eine spezifische Bindung an neutrophile Leukozyten des Kaninchens; die Anlagerung konnte durch nicht-markiertes CP verhindert werden. Nach Injektion von 4-6 ng 125J-CP/kg Körpergewicht in Kaninchen mit experimentellen Abszessen fand eine vorübergehende Neutropenie statt, gefolgt von einer Rebound-Neutrophilie. Das Verhältnis Abszeß zu Muskel (A/M) war 11.6 ± 1.1 nach 6 Std. und 11.0 ± 4.7 nach 24 Std., während das Verhältnis Abszeß zu Blut (A/B) 0.9 ± 0.2 nach 6 Std. und 3.7 ± 0.6, 24 Std. nach der Injektion war. Kontrolltiere, injiziert mit 125J, wiesen ein A/M-Verhältnis von 2.9 ± 0.2 und A/B-Verhältnis von 0.9 ± 0.3, 6 Std. nach der Injektion auf. Die Analyse der Radioaktivität im Blut nach 125J-CP-Gabe zeigte, daß der überwiegende Anteil (> 87%) als 125J-CP in der Plasmafraktion vorhanden war. Unsere Resultate geben Anlaß zur Vermutung, daß Radiojod-markiertes, synthetisches CP ein geeignetes Agens zur Abszeßlokalisierung sein kann. Allerdings ist eine weitere Verfeinerung der Methode notwendig.

Eicosapentaenoic Acid Interferes with U46619-Stimulated Formation of Inositol Phosphates in Washed Rabbit Platelets

1989 ◽  
Vol 62 (04) ◽  
pp. 1116-1120 ◽  
Author(s):  
N Chetty ◽  
J D Vickers ◽  
R L Kinlough-Rathbone ◽  
M A Packham ◽  
J F Mustard
Keyword(s):  
Signal Transduction ◽  
Fatty Acid Composition ◽  
Eicosapentaenoic Acid ◽  
Inositol Phosphates ◽  
Inositol Phosphate ◽  
Dense Granule ◽  
Detectable Change ◽  
Membrane Phospholipids ◽  
Rabbit Platelets ◽  
Stimulation Of

SummaryEicosapentaenoic acid (EPA) inhibits platelet responsiveness to aggregating agents. To investigate the reactions that are affected by EPA, we examined the effect of preincubating aspirintreated rabbit platelets with EPA on stimulation of inositol phosphate formation in response to the TXA2 analogue U46619. Stimulation of platelets with U46619 (0.5 μM) caused aggregation and slight release of dense granule contents; aggregation and release were inhibited by preincubation of the platelets with EPA (50 μM) for 1 h followed by washing to remove unincorporated EPA. Incubation with EPA (50 μM) for 1 h did not cause a detectable increase in the amount of EPA in the platelet phospholipids. When platelets were prelabelled with [3H]inositol stimulation with U46619 of control platelets that had not been incubated with EPA significantly increased the labelling of mos1tol phosphates. The increases in inositol phosphate labelling due to U46619 at 10 and 60 s were partially inhibited by premcubat10n of the platelets with 50 μM EPA. Since the activity of cyclo-oxygenase was blocked with aspirin, inhibition of inositol phosphate labelling in response to U46619 indicates either that there may be inhibition of signal transduction without a detectable change in the amount of EPA in platelet phospholipids, that changes in signal transduction require only minute changes in the fatty acid composition of membrane phospholipids, or that after a 1 h incubation with EPA, activation of phospholipase C is affected by a mechanism that is not directly related to incorporation of EPA.

Trimucytin: A Collagen-Like Aggregating Inducer Isolated from Trimeresurus mucrosquamatus Snake Venom

1993 ◽  
Vol 69 (03) ◽  
pp. 286-292 ◽  
Author(s):  
Che-Ming Teng ◽  
Feng-Nien Ko ◽  
Inn-Ho Tsai ◽  
Man-Ling Hung ◽  
Tur-Fu Huang
Keyword(s):  
Platelet Aggregation ◽  
Snake Venom ◽  
Inositol Phosphate ◽  
Shape Change ◽  
Platelet Activating Factor ◽  
Atp Release ◽  
Platelet Membrane ◽  
Thromboxane B2 ◽  
Dependent Manner ◽  
Concentration Dependent Manner

SummaryTrimucytin is a potent platelet aggregation inducer isolated from Trimeresurus mucrosquamatus snake venom. Similar to collagen, trimucytin has a run of (Gly-Pro-X) repeats at the N-terminal amino acids sequence. It induced platelet aggregation, ATP release and thromboxane formation in rabbit platelets in a concentration-dependent manner. The aggregation was not due to released ADP since it was not suppressed by creatine phosphate/creatine phosphokinase. It was not either due to thromboxane A2 formation because indomethacin and BW755C did not have any effect on the aggregation even thromboxane B2 formation was completely abolished by indomethacin. Platelet-activating factor (PAF) was not involved in the aggregation since a PAF antagonist, kadsurenone, did not affect. However, RGD-containing peptide triflavin inhibited the aggregation, but not the release of ATP, of platelets induced by trimucytin. Indomethacin, mepacrine, prostaglandin E1 and tetracaine inhibited the thromboxane B2 formation of platelets caused by collagen and trimucytin. Forskolin and sodium nitroprusside inhibited both platelet aggregation and ATP release, but not the shape change induced by trimucytin. In quin-2 loaded platelets, the rise of intracellular calcium concentration caused by trimucytin was decreased by 12-O-tetradecanoyl phorbol-13 acetate, imipramine, TMB-8 and indomethacin. In the absence of extracellular calcium, both collagen and trimucytin caused no thromboxane B2 formation, but still induced ATP release which was completely blocked by R 59022. Inositol phosphate formation in platelets was markedly enhanced by trimucytin and collagen. MAB1988, an antibody against platelet membrane glycoprotein Ia, inhibited trimucytinand collagen-induced platelet aggregation and ATP release. However, trimucytin did not replace the binding of 125I-labeled MAB1988 to platelets. Platelets pre-exposed to trimucytin were resistant to the second challenge with trimucytin itself or collagen. It is concluded that trimucytin may activate collagen receptors on platelet membrane, and cause aggregation and release mainly through phospholipase C-phosphoinositide pathway.

Neutrophil Derived Cathepsin G Induces Potentially Thrombogenic Changes in Human Endothelial Cells: a Scanning Electron Microscopy Study in Static and Dynamic Conditions

1994 ◽  
Vol 72 (01) ◽  
pp. 140-145 ◽  
Author(s):  
Valeri Kolpakov ◽  
Maria Cristina D'Adamo ◽  
Lorena Salvatore ◽  
Concetta Amore ◽  
Alexander Mironov ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Extracellular Matrix ◽  
Endothelial Cells ◽  
Thrombus Formation ◽  
Cathepsin G ◽  
Arterial Segment ◽  
Dynamic Conditions ◽  
Activated Neutrophils ◽  
Scanning Electron

SummaryActivated neutrophils may promote thrombus formation by releasing proteases which may activate platelets, impair the fibrinolytic balance and injure the endothelial monolayer.We have investigated the morphological correlates of damage induced by activated neutrophils on the vascular wall, in particular the vascular injury induced by released cathepsin G in both static and dynamic conditions.Human umbilical vein endothelial cells were studied both in a cell culture system and in a model of perfused umbilical veins. At scanning electron microscopy, progressive alterations of the cell monolayer resulted in cell contraction, disruption of the intercellular contacts, formation of gaps and cell detachment.Contraction was associated with shape change of the endothelial cells, that appeared star-like, while the underlying extracellular matrix, a potentially thrombogenic surface, was exposed. Comparable cellular response was observed in an “in vivo” model of perfused rat arterial segment. Interestingly, cathepsin G was active at lower concentrations in perfused vessels than in culture systems. Restoration of blood flow in the arterial segment previously damaged by cathepsin G caused adhesion and spreading of platelets on the surface of the exposed extracellular matrix. The subsequent deposition of a fibrin network among adherent platelets, could be at least partially ascribed to the inhibition by cathepsin G of the vascular fibrinolytic potential.This study supports the suggestion that the release of cathepsin G by activated neutrophils, f.i. during inflammation, may contribute to thrombus formation by inducing extensive vascular damage.

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