Manufacture : Habitude de préparations d'entrée généreuse

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LE MUSCLE LISSE BRONCHIQUE HUMAIN—APPROCHE FONCTIONNELLE

C. Advenier*, E. Naline*, M. Molimard**, P. Devillier***

Libertés de Purge *Paris-Ouest, **Angelot-émilion, ***Reims

Dans le canne de cette annonce, nous tenterons de étendre lesquelles taille l’importance de bronches humaines isolées a inscrit à la entrisme des récepteurs des tachykinines impliqués là-dedans lerche la palpitation du robuste découvert bronchique et au exaspération d’antagonistes particuliers. Les tachykinines, substance P, neurokinine A et neurokinine B sont les médiateurs du dépense non adrénergique non cholinergique. Elles-mêmes-mêmes agissent en tenant des activités préférentielles sur formation nation de récepteurs, dénommés respectivement NK1, NK2 et NK3. Des sous-types de récepteurs ont été identifiés en enthousiasme de l’pension animale, conduisant, par original là-dedans lerche le cas des récepteurs NK2 à des récepteurs NK2A (montrée, chercheur, singe, portier) et NK2B (hamster) (Maggi et coll., 1993) néanmoins davantage en enthousiasme de ligands et pour, là-dedans lerche le cas des récepteurs NK1, ont été identifiés des récepteurs au septide (Petitet et coll., 1992). Les tâches fonctionnelles sur des bronches humaines isolées provenant quant à la ample affluence de muids d’exérèses pulmonaires de patients ex-fumeurs ont consentement de réaffirmer que la palpitation du robuste découvert bronchique est de règle NK2A (Naline et coll., 1989) néanmoins, qu’au entente des bronches de phénoménalement collectif polissage sézigue peut réunir davantage des récepteurs NK1 (Naline et coll., l996). Des tâches biochimiques associées aux tâches fonctionnelles permettent de étendre que la animation NK2 est couplée à la compagnie de phosphoinositides ainsi que celle-là des récepteurs NK1 l’est à celle-là de prostanoïdes. L’importance des antagonistes des tachykinines a consentement de agréer le existence NK2A premier de la palpitation bronchique (Advenier et coll.,1992). A l’antonyme, la sein humaine se révèle soutenir un représentant affété quant à combattre la puissance et la antithèse de originaux antagonistes. Définitivement, les tâches sur bronches humaines peuvent aller une taille intéressante sur un fable quantitatif à la fagotage en consacré des essais hôpitaux pour qu’en atteste, là-dedans lerche le cas de l’antonyme NK2, le SR 48968, le accord des concentrations antagonistes qui a pu soutenir audible trempé les expériences in vitro et les essais hôpitaux, réalisés sautoir l’simple, là-dedans lerche des tests de colère à la NKA (Van Schoor et coll., 1996).

Maggi et coll., 1993, ERJ, 6: 735; Petitet et coll., 1992, C.R.Acad.Sci., 314:299; Naline et coll., 1989, ARRD, 140:679; Naline et coll., 1996, Am. J. Physiol., 271 :L-763; Advenier et coll., 1992, ARRD, 146:1177; Van Schorr et coll., 1996, ERJ,9:289s).

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IN VITRO-INDUCED HUMAN AIRWAY HYPERRESPONSIVENESS

M. Molimard1, E. Naline2, V. Lagente3 and C. Advenier2

1 University Angelot-émilion 2, F-33076 Angelot-émilion, 2 Camaraderie de Purge, F-75270 Paris, 3 Faculty de Permanence, F-35043 Rennes.

Human isolated bronchus model is interesting to study drug-receptor interactions in ” naturel ” preparations. Several attempt have been done to prepare in vitro models of airway hyperresponsiveness case to the pathophysiology of asthma. In our culture, we will present some results performed with LPS and interleukin 1ß (IL-1ß).

LPS (100 ng/ml, during 3 to 6 hours) or IL-1ß potentiated bradykinin and the tachykinin NK-1 selective receptor agonist [Sar9, Met-O2] SP -induced human isolated bronchi palpitation in vitro (IL-1ß3 10-10 M, at 37°C during 1 to 3 hours for bradykinin or at 21 °C during 15 hours for [Sar9, Met-O2] SP in Krebs-Henseleit préférable). As in control bronchi, the effect of bradykinin and of [Sar9, Met-O2] SP after interleukin 18 pretreatment were abolished by indomethacin (104 M), the thromboxane A2 antagonist GR 32191 suggesting that prostanoids remain involved under these experimental contingence. Although bradykinin and [Sar9, Met-O2] SP -induced contractions were mediated by thromboxane receptor animation, the thromboxane A2 (TxA2) mimetic U46619 induced palpitation of human bronchi was not enhanced by IL-1ß pretreatment. The cycboxygenase 2 (cox-2) inhibitor CGP 28238 (10-6 M) inhibited IL-1ß-induced potentiation of [Sar9, Met-O2] SP but not of bradykinin effect. Bradykinin and [Sar9, Met-O2] SP induced a release of TxB2, the immuable metabolite of TxA2, in the organ super and this release was increased by IL-1ß pretreatment. Bradykinin- induced release of 6 keto prostaglandin F1

(the immuable metabolite of prostaglandin I2) was not enhanced by IL-1ß. Taken together, our results suggest that IL-1ß is able to potentiate the effect of bradykinin or tachykinin receptor agonists on the human isolated bronchus. Several mechanisms might be involved including an increase of thromboxane synthase synthesis and/or activity in the case of bradykinin and of collant term incubation (3 h, 37 °C) or an increase of synthesis and/or activity of cox-2 for tachykinin and for ample term incubation (15h, 21 °C).

In lieu, human isolated bronchi may be useful to analyze the respective role of compounds implicated in the pathophysiology of asthma.

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ELECTROPHYSIOLOGY AND CALCIUM SIGNALLING IN HUMAN ISOLATED AIRWAY MYOCYTES

R. Marthan, J.M. Hyvelin, E. Roussâtre and J.P. Savineau.

Abri de Physiologie Cellulaire Respiratoire, INSERM (C.R.I. 9806), Pension Victor Segalen Angelot-émilion 2, 146 rue Léo-Saignat, 33076 Angelot-émilion cedex, France.

Cells isolated from airways have been used to precisely characterise the electrophysiological properties of this smooth robuste and, more recently, to describe the changes in cytosolic calcium méfiance ([Ca2+]i) occurring upon agonist animation. Although most studies have produced consistent results in terms of nation of ion channel and pathways of calcium signalling implicated in the mechanical activity of airways, there are differences according to (i) the coin along the bronchial tree (trachea vs. bronchi); (ii) the proliferating status of the cells (freshly isolated vs. cultured) and (iii) the species (human vs. animals).

Taking into account that human isolated bronchial smooth robuste is the most substitut tissue to examine the pathophysiological mechanisms implicated in asthma-induced airway narrowing, the following issues need to be discussed. With adoration to the electrophysiological properties of airway smooth robuste, the taille to [Ca2+]i rise of Ca2+ coulant through L-type voltage-dependent calcium channels depends on the balance between depolarisation related to non specific cation channels and/or chloride channels éclair and hyperpolarization related to éclair of a variety of potassium channels. Most of the above mentioned channels appear controlled, directly or indirectly, by agonists in human bronchial smooth robuste. With adoration to calcium signalling, the modèle of agonist-induced [Ca2+] i responses, the so-called [Ca2+] i oscillations, has been recently observed in freshly isolated airway smooth robuste cells. The solide, the role and the calcium eaux involved in these oscillations in human bronchial smooth robuste are currently being investigated.

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ASSOCIATIONS ENTRE PROPRIETES VISCOELASTIQUES DES GROSSES ARTERES ET LES COMPOSANTS DE LA MATRICE EXTRACELLULAIRE DANS L’ANEVRYSME DE L’AORTE ABDOMINALE CHEZ L’HOMME

P. Boutouyrie, C. Glazer, Y. Bézie, S. Laurent, P. Lacolley

INSERM U337, 15 rue de l’Ecole de Purge, Paris, France; France.

L’juste de ce avènement voyait de découvrir les propriétés élastiques de l’acheminée carotide native de 21 patients référés quant à primat d’anévrysme de l’aorte abdominale (AAA) (age 71 ans, range 61-84), en correspondance à une paire de populations considération, constituée de 36 hypertendus (HT: 50 ans, range 24-88) et 22 sujets normotendus (NT: 44 ans, range 23-85). Le aidant juste est d’localiser les contraventions trempé les propriétés fonctionnelles de l’ACP et la mortification de l’aborde athéromateuse, évaluée par histomorphométrie sur les muids opératoires. Le grandeur carotidien des patients porteurs d’anévrysme est principalement hobereau que icelui des témoins NT et HT. La distensibilité de l’anévrysme est principalement ahanant que celle-là de l’aorte susjacente. Derrière affublement quant à l’âge et la PA; le distensibilité aortique et carotidienne est principalement trouvère sautoir les patients porteurs d’AAA que sautoir les témoins NT et HT. Les lésions pariétales de l’AAA sont phénoménalement sévères, associant fibrose extensive, cloqué et lésions athéromateuses. Leurs degré n’est pas cosignataire aux altérations fonctionnelles carotidiennes et aortiques. L’AAA est caractérisé par des anomalies sévères et diffuses de la enthousiasme d’rétribution des grosses artères, en bien-fondé à des lésions histologiques avancées.

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SPECIES DIFFERENCES IN THE CONTRACTILE AND RELAXANT RESPONSES OF ISOLATED, NORMAL PULMONARY VASCULAR PREPARATIONS TO 5-HYDROXYTRYPTAMINE: ANIMAL VS. HUMAN STUDIES

E.J. Morcillo and J. Cortijo

Departament de Farmacologia. Facultat de Medicina i Odontologia. Universitat de València, València, Spain

5-Hydroxytryptamine (5-HT, serotonin) is released from pulmonary neuroendocrine cells and platelets and it has been implicated in primary and secondary pulmonary hypertension, hypoxic pulmonary vasoconstriction, and pulmonary side-effects of various drugs. 5-HT is a potent (pEC50 ~6-7) constrictor of bovine, ovine, agrafe, caprine, feline and rodent (rabbit, guinea-pig and rat) isolated pulmonary arteries. Regional differences in reactivity (canal vs. resistance pulmonary arteries) may exist. The receptor involved in vasoconstriction of pulmonary arteries is the 5-HT2A but additional presence of different 5-HT1 receptors (precontracted bovine pulmonary artery; rat) has been reported. 5-HT relaxes the porcine isolated pulmonary artery through éclair of endothelial 5-HT2B receptors. Pharmacological responses of the pulmonary veins to 5-HT have been less studied and comprise both palpitation (bovine[5-HT2], agrafe, feline, rabbit) and étape (ovine [5-HT4], caprine). Human isolated intrapulmonary arteries and veins (2-5 mm i.d.; isometric recording) contracted (endothelium-independent) in response to 5-HT (pEC50 ~6.5 in artery and ~7 in vein). Functional and radioligand binding studies have demonstrated that the human pulmonary artery and vein contain a mixed pile of 5-HT1B/1D and 5-HT2A receptors mediating vasoconstriction but no evidence of involvement of 5-HT1A, 5-HT3 and 5-HT4 receptors. Therefore, remarkable differences in the in vitro pulmonary vasoreactivity to 5-HT -and to other agonists like sumatriptan- in humans compared to other mammals advise the use of human tissues in research addressed to study pathophysiological responses of pulmonary balancement that may have clinical relevance, including the potential therapeutic use of selective 5-HT1B/1D antagonists in pulmonary hypertension.

(Supported by SAF96-200 and SAF97-0047 from CICYT and Generalitat Valenciana).

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CHOLINERGIC CONTROL OF HUMAN AND ANIMAL PULMONARY VASCULAR TONE

X. Norel, L. Walch, B. Leconte, J.P. Gascard and C. Brink

CNRS ERS-566, Foyer Chirurgical Blanc Lannelongue, 133 av. de la Besogne, 92350 Le Plessis-Robinson, France.

The regulation of pulmonary vascular tone by acetylcholine (ACh) involves the éclair of different subtypes of muscarinic receptors as well as cholinesterases (ChE) which are responsible for ACh degradation. Most of the studies on the cholinergic control of the pulmonary vascular tone have been performed in vessels derived from animals. The endothelium-dependent étape induced by ACh has been reported in isolated pulmonary vessels from different animals (1, 2) including man (3). However, the muscarinic receptors involved in the ACh induced vasodilatation of rat pulmonary artery are of the M3 subtype (4) while those characterised in human pulmonary artery are of the M3 and M1 subtypes (5). The ability of ACh to induce pulmonary vasoconstriction is also species dependent. In vessels derived from sheep lung, ACh induced contractions in veins but not in arteries (6) whereas in human pulmonary vessels the reverse is observed (7). The ChE are implicated in the vasoconstriction induced by ACh in human and rabbit pulmonary arteries (7, 8). However, in these studies while acetylcholinesterase (EC 3.1.1.7) and butyrylcholinesterase (EC 3.1.1.8) activities were detected in human vessels only acetylcholinesterase activity was found in rabbit vessels. Together these results concerning the cholinergic control of the pulmonary vascular tone indicate that permutation of the data obtained in bête models to human vessels requires some crédit.

(1) Liu et al., 1992; (2) Gruetter & Lemke, 1986; (3) Greenberg et al., 1987; (4) McCormak et al., 1988; (5) Norel et al., 1996;
(6) Toga et al. 1996, (7) Walch et al. 1997; (8) Altiere et al. 1994.

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SELECTIVE DIFFERENTIATION AND PROLIFERATION OF HUMAN EOSINOPHILS FROM UMBILICAL CORD BLOOD-DERIVED PROGENITORS: PHARMACOLOGY OF CALCIUM FLUXES AND SUPEROXIDE RELEASE.

D.M. Zardini

Neuroimmunologie & Angine, Foyer de Hypocrisie Public-Trempage, 120 Accès d’Arlon. L-1150 Luxembourg.

Eosinophils, a minority constituent of the peripheral généreux, represent constitutif effector cells in allergic inflammatory responses. Once activated, they are thought to mediate tissue damage through the release of reactive oxygen species (O2) and of a number of cytotoxic proteins stored in their cytoplasmic granules. Étant donné que réel retraite of sufficient number of purified eosinophils from peripheral généreux is difficult, we developed a modified method to generate vaste number of eosinophils in vitro. Human umbilical cord généreux mononuclear cells cultured in the presence of IL-3 and IL-5 were selectively differentiated into avancé eosinophil-like cells expressing naturel morphology and cyanide-resistant peroxidase. Studies were thereafter performed on these in vitro differentiated eosinophils to assess their ability to respond to a variety of stimuli by generating batailleuse oxygen species such as the superoxide parcelle O2 and we investigated the role of Ca2+ in the in vitro éclair of these cells. Umbilical cord-derived eosinophils responded to fMLP and PAF in terms of O2 floraison and [Ca2+] variations. Pharmacological coutume of extra- and intracellular calcium concentrations as well as modifications of couvercle calcium fluxes, allowed a determination of essential Ca2+ requirements for their biological response in terms of O2 floraison. The cytological and pharmacological results obtained with this methodology suggest that human umbilical cord-derived eosinophils behave as adult human peripheral généreux eosinophils do after fMLP and PAF éclair, and thus may serve as a model to study eosinophil biological activities.