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lördag 9 december 2017

(2015) Astma, 15-HETE ja eoxiinit . Eoxiini C4, EXC4

Allergisessa astmassa  eräs  vaikuttaja 15-HETE ja eoxiini C4, EXC4

https://www.sciencedirect.com/science/article/pii/S1098882315000520

Pe  8.12. 2017 sain kirjastosta tämän  Karoliinisen instituutin  artikkelin  vuodelta 2015 kokonaisuudessaan:
Siinä on kuvattu molekyyli  EXC4, eoxiini C4.

Original Research Article
On the biosynthesis of 15-HETE and eoxin C4 by human airway epithelial cells
Author
Åsa Brunnström
YlvaTryselius
StinaFeltenmark
Erik Andersson
Helene Leksell
AnnaJames
Bengt Mannervik
Barbro Dahléne
Hans-Erik Claessona

https://doi.org/10.1016/j.prostaglandins.2015.04.010
Highlights

• Primary human airway epithelial cells have high expression of 15-LO-1.
• Primary human airway epithelial cells can produce EXC4.
• Airway epithelial cells produce increased amounts of 15-HETE after bacterial infection.
• Conversion of EXA4 to EXC4 is catalyzed by soluble GSTs in epithelial cells.
• Bronchial biopsies demonstrated co-expression of 15-LO-1 and GST P1-1.
Abstract

Several lines of evidence indicate that 15-lipoxygenase type 1 (15-LO-1) plays
a pathophysiological role in asthma.

The aim for this study was to investigate the 15-LO-1 expression and activity
in primary human airway epithelial cells cultivated on micro-porous filters at
air–liquid interface. Incubation of human airway epithelial cells with arachidonic acid led to the formation of
15(S)-hydroxy-eicosatetraenoic acid (15-HETE) and
 exposing the cells to
 bacteria or physical injury markedly increased their production of 15-HETE.

 The cells were also found to convert arachidonic acid to eoxin C4 (EXC4).
Subcellular fractionation revealed that the conversion of EXA4 to EXC4 was
 catalyzed by a soluble glutathione transferase (GST). The GST P1-1 enzyme
was found to possess the highest activity of the investigated soluble GSTs.

 Following IL-4 treatment of airway epithelial cells, microarray analysis
confirmed high expression of 15-LO-1 and GST P1-1, and immunohistochemical
staining of bronchial biopsies revealed co-localization of 15-LO-1 and GST
P1-1 in airway epithelial cells.

These results indicate that respiratory
infection and cell injury may activate the 15-LO pathway
 in airway epithelial cells. Furthermore, we also demonstrate that airway
epithelial cells have the capacity to produce EXC4.

torsdag 7 december 2017

Miten LTE4 eliminoituu kehosta? Leukotrieenit

LTE elimination

    Format: Abstract

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J Biol Chem. 1990 Dec 15;265(35):21771-8.
Leukotriene E4 elimination and metabolism in normal human subjects.
Sala A1, Voelkel N, Maclouf J, Murphy RC.
Author information
Abstract

Radiolabeled leukotriene (LT) E4 was infused into three healthy subjects in order to assess
 the production and elimination of sulfidopeptide leukotriene metabolites in urine.
 Three different radiolabeled tracers were employed,
[14,15-3H]LTE4,
[35S]LTE4,
 and [14C] LTE4

in five separate infusion studies.

 There was a rapid disappearance of
radioactivity from the vascular compartment in an apparent two-phase process.
 The first elimination phase had an apparent half-life of approximately 7 min.
Radioactivity quickly appeared in the urine with 10-16% eliminated during the
first 2 h following intravenous infusion; 7%,
 2-5 h; 4%,
5-8 h; 4%,
8-15 h;
and 1.5%, 15-24 h from the [14C] LTE4 experiments.
Unmetabolized LTE4 was the major radioactive component in the first urine collection,
but at later times two more polar compounds predominated.
After extensive purification by normal phase-solid phase extraction and reverse-phase
 high performance liquid chromatography, these compounds were characterized by UV spectroscopy,
 co-elution with synthetic standards, negative ion electron capture gas chromatography/mass spectrometry,
and tandem mass spectrometry. The two major urinary metabolites were structurally determined
to be 14-carboxy-hexanor-LTE3 and
the conjugated tetraene, 16-carboxy-delta 13-tetranor-LTE4.
 Three other minor metabolites were detectable in the first urine collection
 only and were characterized by co-elution with synthetic standards as
16-carboxy-tetranor-LTE3,
 18-carboxy-dinor-LTE4, and
20-carboxy-LTE4. 

omega-Oxidation and subsequent beta-oxidation from the methyl terminus appeared to be the major metabolic
fate for sulfidopeptide leukotrienes in man.

The accumulation of the 14-COOH-LTE3 and 16-COOH-delta 13-LTE4
may reflect a rate-limiting step in further oxidation of these compounds which places a conjugated triene or conjugated tetraene, respectively,
two carbons removed from the CoA ester moiety.

 Also in the first urine collection there was another minor metabolite identified as N-acetyl-LTE4,
however, no subsequent beta-oxidation of this metabolite was observed.

The major metabolites of LTE4 might be useful in assessing in vivo production of sulfidopeptide leukotrienes in humans.

PMID:
    2174886

    [Indexed for MEDLINE]

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(Jossain huomasin myös maininnan siitä, että terve maksa ja munuainen on edellytys LTE-;n hyvään eliminaatioon).
Lieneekö sekin niiät kehon luonnollisen immunologisen puolustuksen molekyylejä joita on tietty olevainen määrä  valmiina näihin äkkireaktioihin, joisa tarkoitus on tietysti ensisijassa   kynnystasossa puolustuksellinen, vaikka  ylivoimakkaana reaktiona  ilmeneekin astma-anafylaksia ja  siihen  ei mene  yli 10 minuuttia.
Jos LTE  minimimäärässä olisi fysiologinen sillä olisi jokin  normaali pitoisuus.   Tosin se on  aggressiivisena vaikuttajana  nopeasti kehkeytettävissä  järjestelmänsä lopputuotteena  (AA-  LTA4 linja LTC4,LTDF4-LTE4).
Toisaalta  LTE4:n  nopea katoaminen voisi  merkitä sitäkin, että sillä on tietty jatkuva muodostuminen  ja jos ei ole  reagoimisen  tarvetta niin se nopeasti katoaakin ja poistuu kehosta -  kuten IgA-virta  on jatkuvaa ja  erittyy sitten limakalvoilta pois kehostaa.
Entä jos LTE4 ei pystyisi muodostumaan ollenkaan? Otan yhden sitaatin netistä:


Lancet. 1998 Nov 7;352(9139):1514-7.

Leukotriene C4-synthesis deficiency: a new inborn error of metabolism linked to a fatal developmental syndrome.

Abstract

BACKGROUND:

Cysteinyl leukotrienes (LTC4, LTD4, LTE4) are potent lipid mediators derived from arachidonic acid in the 5-lipoxygenase pathway that exert profound biological effects. We investigated synthesis and metabolism of leukotrienes in an infant who presented with muscular hypotonia, psychomotor retardation, failure to thrive, and microcephaly. The course of the disease was rapidly progressive and the infant died aged 6 months.

METHODS:

Cysteinyl leukotrienes and LTB4 were analysed in cerebrospinal fluid, plasma, urine, and stimulated monocytes by EIA. We measured [3H]-LTC4 formation from [3H]-LTA4 in monocytes and platelets by radio-high-pressure liquid chromatography.

FINDINGS:

Concentrations of LTC4 and its metabolites were below the detection limit in the cerebrospinal fluid, plasma and urine. LTC4 could not be generated in stimulated monocytes, whereas LTB4 synthesis was increased. [3H]-LTC4 could not be made from [3H]-LTA4 in the patient's monocytes or platelets.

INTERPRETATION:

In this patient, inability to synthesise LTC4 suggests a deficiency of LTC4 synthase. This defect is a new inborn error of human eicosanoid metabolism and may be associated with the clinical disorder. Leukotriene analysis should be done in all patients with neurological symptoms who are candidates for metabolic diseases.

Comment in


(2007) EOXIINIT(EXA4, EXC4, EXD4, EXE4)

Eoxiinit MUODOSTUVAT 15-HpETE TIETÄ, MUTTA MUODOSTUKSESSA ON JOITAIN  TUNTEMATTOMIA KOHTIA
 TÄMÄN Wikiåedia-TIEDON PERUSTEELLA
Kuitenkin artikkelissa huomataan että kyse on eosinofileista ja mastsoluista
 reaktioaineitten muodostuksessa, joten  mastsolustabilaattoreita
on esim  Lomudal, Na- kromoglikat lääke.   ja  LTE4- sarjan reaktiota taas lieventää  montelukast, antileukotrieenilääke,  Singulair.

https://en.wikipedia.org/wiki/Eoxin


  1. charlotte Edenius *,
  2. Lennart Lindbom ,
  3. Magnus Björkholm , and
  4. Hans-Erik Claesson * , , **
  1. Communicated by Bengt Samuelsson, Karolinska Institutet, Stockholm, Sweden, November 2, 2007 (received for review July 27, 2007)

Abstract

Human eosinophils contain abundant amounts of 15-lipoxygenase (LO)-1. The biological role of 15-LO-1 in humans, however, is unclear. Incubation of eosinophils with arachidonic acid led to formation of a product with a UV absorbance maximum at 282 nm and shorter retention time than leukotriene (LT)C4 in reverse-phase HPLC. Analysis with positive-ion electrospray tandem MS identified this eosinophil metabolite as 14,15-LTC4. This metabolite could be metabolized to 14,15-LTD4 and 14,15-LTE4 in eosinophils. Because eosinophils are such an abundant source of these metabolites and to avoid confusion with 5-LO-derived LTs, we suggest the names eoxin (EX)C4, -D4, and -E4 instead of 14,15-LTC4, -D4, and -E4, respectively.

Cord blood-derived mast cells and surgically removed nasal polyps from allergic subjects also produced EXC4. Incubation of eosinophils with arachidonic acid favored the production of EXC4, whereas challenge with calcium ionophore led to exclusive formation of LTC4.

Eosinophils produced EXC4 after challenge with the proinflammatory agents LTC4, prostaglandin D2, and IL-5, demonstrating that EXC4 can be synthesized from the endogenous pool of arachidonic acid.

 EXs induced increased permeability of endothelial cell monolayer in vitro, indicating that EXs can modulate and enhance vascular permeability, a hallmark of inflammation. In this model system, EXs were 100 times more potent than histamine and almost as potent as LTC4 and LTD4. Taken together, this article describes the formation of proinflammatory EXs, in particular in human eosinophils but also in human mast cells and nasal polyps.

Funktioilta tuntemattomia eoxamideja olemassa

Eoxamides

The same pathways that metabolize arachidonic acid to eoxines have been shown to metabolize anandamide, N-arachidonoylethanolamine (i.e. arachidonic acid containing ethanolamine esterified to its carboxy residue) into a set of eoxamides that are identical to their eoxin counterparts except that they possess an ethanolamine ester. These metabolites have been named EXA4 ethanol amide, EXC4 ethanol amide, EXD4 ethanol amide, and EXE4 ethanol amide. These products were formed by the L1236 Reed Sternberg cell line presented with anandamide; human platelets presented with eoxamideA4 produced EXC4 ethanol amide, EXD4 ethanol amide, and EXE4 ethanol amide. The activity and function of these ethanol amide metabolites has not been reported.[4]

Dermatiitin tapahtumia rasvahapponäkökulmasta

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Br J Dermatol. 2016 Jul;175(1):163-71. doi: 10.1111/bjd.14521. Epub 2016 Apr 28.
N-Acyl ethanolamide and eicosanoid involvement in irritant dermatitis.
Kendall AC1, Pilkington SM2,3, Sassano G4, Rhodes LE2,3, Nicolaou A1.
Author information
Abstract
BACKGROUND:

Sodium lauryl sulfate (SLS) and ultraviolet radiation (UVR) are two commonly encountered cutaneous inflammatory stimuli. Differing histopathological and clinical features implicate involvement of alternative inflammatory pathways; bioactive lipid mediators (eicosanoids, endocannabinoids and sphingolipids) are likely candidates for regulation of the divergent inflammatory responses.
OBJECTIVES:

To assess comprehensively bioactive lipid involvement in SLS- and UVR-induced inflammatory responses, to provide a better understanding of bioactive lipid mediator pathways in irritant inflammation.
METHODS:

Buttock skin from 10 healthy volunteers was treated with two minimal erythema doses of UVR (275-380 nm, peak 305 nm) or an SLS dose optimized for each individual, to produce a comparable, moderate erythema. Punch biopsies were taken 24 h postchallenge and from untreated skin, and separated into dermis and epidermis. Lipids [including 15 prostanoids, 15 hydroxy fatty acids (HFAs), nine endocannabinoids and related N-acyl ethanolamides (NAE), and 21 sphingolipids] were extracted and quantified using liquid chromatography-tandem mass spectrometry.
RESULTS:

Increased epidermal NAE and HFA expression was observed in response to SLS but not UVR-induced low-level inflammation. Significant changes following SLS treatment included augmented levels of NAE, possessing proinflammatory and some reported anti-inflammatory properties, with 3·7-fold (P = 0·02) and threefold (P = 0·01) increased expression of palmitoyl and stearoyl ethanolamides, respectively, in addition to 1·9-fold (P = 0·02) increased expression of 12-hydroxyeicosatetraenoic acid (12-HETE).
CONCLUSIONS:

The differential bioactive lipid upregulation implicates their involvement in skin irritant responses, potentially reflecting roles in inflammatory cell recruitment and subsequent resolution of inflammation, giving scope for new treatment approaches to irritant dermatitis.

© 2016 British Association of Dermatologists.
Comment in

    Deciphering the lipidomic profile of irritant contact dermatitis. [Br J Dermatol. 2016]

PMID:
    26947140
DOI:
    10.1111/bjd.14521

    [Indexed for MEDLINE]

måndag 4 december 2017

Linolihappo ja suolistobakteerivaikutus

Linolihappo on ihmiselle essentielli rasvahappo  C18:2 n6 eli omega-6 -rasvahappo. Sillä on erittäin monta nimeä. Siinä on 18 hiiltä ja kaksi kaksoisidosta.  Siitä on tehty tutkimus, jossa katsotaan,mitä metaboliitteja suolistobakteeri voi siitä tehdä ja mikä edullinen vaikutus  suolen epiteeliin  voi ilmetä.

Tässä on mainittu Lactobacillus  plantarum  ja  viisi  tuotetta linolihaposta: Lyhennykset ovat  HYA, HYB, KetoA, KetoB, ketoC ja niitten vaikutuksia on tutkittu tässä työssä.
http://www.jbc.org/content/290/5/2902.full
Kuvataan  tie mitä, kautta  HYA- metaboliitilla on edullista vaikutusta suoliston epiteelin barrierifunktion kohentamiseen.

Mainitsen  yllämainittujen  metaboliittien nimet:
HYA ,   10-HYDROXY-CIS-12- OCTADECENOIC ACID
HYB, 10-HYDROXY-OCTADECANOIC ACID
KetoA, 10-OXO-cis-12- OCTADECENOIC ACID
KetoB, 10-OXO-OCTADECANOIC ACID
KetoC, 10-OXO-trans-11-OCTADECENOIC ACID

 Sekä linolihaposta C18:2 n6  että öljyhaposta C16:1 n9   voi tulla  HYB- muotoa.

KetoC- muodosta  haaroittumalla voi tulla konjugoituja linolihappoja: 9c,11t-LA ja 9t,11t-LA .

Artikkelissa esitettiin kaavakuvana, mitä tietä  linolihappometaboliitti HYA  vaikuttaa  kohenemista  suoliston epiteelibarrierissa coliitissa ja IBD  tapaisessa tilanteessa.
HYA vaikuttaa  GPR40 reseptoriin  ja MEK-ERK  välitteisesti suppressoi  TNFR2  Kun TNFR2  täten säätyy alas,  säätyy myös alavirrassa  NFkB alas ja suolistoepiteelibarrieri pääsee toipumaan.
Nimittäin  IFNgamma  stimuloi TNFR2- tietä  makrofageja ja neutrofiilejä, tulehduksellisia soluja    ja  TNF-alfa  vaikuttaa  stimuloiden NFkB:n ylössäätymistä.

TNFR2 on kandidaattimolekyyli  kehitettäessä terapiaa IBD-hoitoon.

Oma kommentti:
 Essentiellin  rasvahapon   edullista vaikutusta suolistoedulliseen suuntaan  ilmeisesti tukee normaali  mikroflora suolessa ja sen ylläpitämisessä on tärkeää kuituravinto.  Mikrofloralla on kyky tehdä paljon metaboliitteja  ravinnon tuomista molekyyleistä.
Jo kymmeniä vuosia sitten pidettiin linolihappoa esim  mahan limakalvon lääkkeen kaltaisena 10 ml - 15 ml annoksena.  Linolihapo sinänsä ei varmaan ole se vaikuttava  lääke, vaan siitä johtuvat  aineenvaihdunnalliset tuotteet, kuten  eikosanoidit.  Kutienkin kasvisöljyn käytössä pitää pidättäytyä ilmeisesti kohtuulliseen käyttöön, sillä niiden jouduttua   ylimäärissä aineenvaihduntaan  tulee uusia onglemia tuntemattomista osista niiden aineenvaihdunnan karttaa.  Nykyään tunnetaan enemmän niitä katabolisia teitä.  Mainttakoon 4 -HNE,  , yhdeksän hiilen  metaboliitti  4-hydroperoksinonenaali  4-HPNE ja  4-hydroxynonenaali 4-HPE joita tuottuu  PUFA- rasvahappojen aineenvaihdunnan lopputuotteina myös linolihaposta.  Noiden tuotteiden rinnalla suoliston  bakteerien muokkaamat tuotteet ovat vaarattomampia  soluille.

Muistiin  4.12. 2017 


torsdag 19 oktober 2017

Lipoxiini LXA4 ja aspiriini

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2196289/

J Exp Med. 1997 May 5; 185(9): 1693–1704.
PMCID: PMC2196289
Articles

Aspirin-triggered 15-Epi-Lipoxin A4 (LXA4) and LXA4 Stable Analogues Are Potent Inhibitors of Acute Inflammation: Evidence for Anti-inflammatory Receptors

Abstract

Lipoxins are bioactive eicosanoids that are immunomodulators. In human myeloid cells, lipoxin (LX) A4 actions are mediated by interaction with a G protein–coupled receptor. To explore functions of LXA4 and aspirin-triggered 5(S),6(R),15(R)-trihydroxy-7,9,13-trans-11-cis–eicosatetraenoic acid (15-epi-LXA4) in vivo, we cloned and characterized a mouse LXA4 receptor (LXA4R). When expressed in Chinese hamster ovary cells, the mouse LXA4R showed specific binding to [3H]LXA4 (Kd ≈ 1.5 nM), and with LXA4 activated GTP hydrolysis. Mouse LXA4R mRNA was most abundant in neutrophils. In addition to LXA4 and 15-epi-LXA4, bioactive LX stable analogues competed with both [3H]LXA4 and [3H]leukotriene D4 (LTD4)– specific binding in vitro to neutrophils and endothelial cells, respectively. Topical application of LXA4 analogues and novel aspirin-triggered 15-epi-LXA4 stable analogues to mouse ears markedly inhibited neutrophil infiltration in vivo as assessed by both light microscopy and reduced myeloperoxidase activity in skin biopsies. The 15(R)-16-phenoxy-17,18, 19,20-tetranorLXA4 methyl ester (15-epi-16-phenoxy-LXA4), an analogue of aspirin triggered 15-epi-LXA4, and 15(S)-16-phenoxy-17,18,19,20-tetranor-LXA4 methyl ester (16-phenoxy-LXA4) were each as potent as equimolar applications of the anti-inflammatory, dexamethasone. Thus, we identified murine LXA4R, which is highly expressed on murine neutrophils, and showed that both LXA4 and 15-epi-LXA4 stable analogues inhibit neutrophil infiltration in the mouse ear model of inflammation. These findings provide direct in vivo evidence for an anti-inflammatory action for both aspirin-triggered LXA4 and LXA4 stable analogues and their site of action in vivo.
Lipoxins are trihydroxytetraene-containing eicosanoids that are generated within vascular lumen by plateletleukocyte interactions and transcellular biosynthetic pathways during multicellular responses such as inflammation, atherosclerosis, and thrombosis (as reviewed in reference 1). This branch of the eicosanoid cascade generates specific tetraenecontaining products that appear to function as stop signals. In this regard, lipoxins display selective actions on human leukocytes in vitro that include inhibition of (a) FMLP and leukotriene B4 (LTB4)1-induced neutrophil chemotaxis (2), (b) FMLP-induced neutrophil transmigration through epithelial cells (3), and (c) neutrophil adhesion and transmigration with endothelial cells (4). We have recently shown that these actions of lipoxin (LX) A4; 5(S),6(R),15(S)-trihydroxy7,9,13-trans-11-cis-eicosatetraenoic acid are mediated via signal transduction events initiated by engagement of highaffinity G protein–coupled receptors in human cells (46). This includes LXA4-induced downregulation of CD11b/ CD18 in human neutrophils (5), an adhesion molecule that plays an important role in endothelial–leukocyte interactions (7). Although lipoxins do not directly inhibit the generation of reactive oxygen species by activated neutrophils (reviewed in reference 8), the ability of LX to block endothelial cell–leukocyte interactions (4) can also prevent injury initiated by leukocyte-derived reactive oxidants (9, 10). Taken together, these results suggest that lipoxins play important regulatory roles in leukocyte trafficking and inflammation.
The biosynthesis of lipoxins is initiated through cell–cell and lipoxygenase (LO) interactions that are regulated by specific cytokines (1). One major pathway is mounted during PMN–platelet interaction and involves both the 5-LO and 12-LO, and the other involves interactions between the 5-LO and 15-LO (recently reviewed in reference 8) that are controlled by the cytokines IL-4 and IL-13 (11). Given the wide use of aspirin, the mechanism of aspirin's beneficial actions in inflammation remains a topic of intense interest. Aspirin has no direct impact on the lipoxygenases (8). In this regard, a third major pathway for lipoxin biosynthesis was recently uncovered, which involves prostaglandin H synthase-II (PGHS-II) in endothelial cells and 5-LO in leukocytes that generate novel 15-epi-lipoxins when PGHS-II is acetylated after treatment with aspirin (12). The aspirin-triggered lipoxins, for example, 5(S),6(R),15(R)- trihydroxy-7,9,13-trans-11-cis-eicosatetraenoic acid (15-epiLXA4), carries its C-15 alcohol in the R configuration, instead of S as in native LXA4, and has potent inhibitory actions in neutrophil adhesion, and 15-epi-LXB4 blocks cell proliferation in vitro (12, 13). This pathway that leads to 15-epiLXA4 may mediate, in part, some of the beneficial actions of aspirin.
Lipoxins are also generated in vivo in humans and in experimental animals (reviewed in reference 8). LXA4 and LXB4 are both formed in ischemic rat brain (14), and LXA4 is generated in mouse kidneys with glomerulonephritis in a P-selectin–dependent fashion predominantly via interactions between platelets and neutrophils (15). In rats, the infiltration of neutrophils to glomerulonephritic kidneys is markedly inhibited by prior exposure of neutrophils to LXA4 (16). Also, LXA4 has recently been found to regulate LTB4mediated delayed hypersensitive reactions in guinea pig (17). The actions of LXA4 are not mediated by competition at the LTB4 receptor (18), but LXA4 is reported to antagonize the formation of intracellular signals such as IP3 (19). In addition to its selective actions with leukocytes, LXA4 also modulates the vasoconstrictor actions of leukotriene D4 (LTD4) in renal hemodynamics and is vasodilatory (20). These actions of LXA4 are mediated by a receptor distinct from that of the myeloid LXA4R and are consistent with LXA4 acting on a subtype of the peptido-leukotriene receptors, competing for LTC4 and LTD4 high-affinity sites that are present on both mesangial (20) and endothelial cells (21). Interest in the actions of LXA4 is also heightened by findings with human subjects that indicate that LXA4 administration via inhalation significantly blocks airway constriction in asthmatic subjects (22).
To explore biological functions of both lipoxins and the recently identified aspirin-triggered lipoxins in vivo, it is essential to identify the molecular basis of their response in experimental animals. To this end, we report here isolation of the mouse lipoxin A4 receptor (LXA4R) and that stable analogues of LXA4 and the aspirin-triggered 15-epi-LXA4 that specifically compete at this site are potent inhibitors of acute neutrophil infiltration in vivo.