0000000000076468
AUTHOR
V. Villagrasa
showing 7 related works from this author
EFFECTS OF PHORBOL 12,13-DIACETATE AND ITS INFLUENCE ON SPASMOGENIC RESPONSES IN NORMAL AND SENSITIZED GUINEA-PIG TRACHEA
1995
Abstract We have studied the effects of phorbol 12,13-diacetate (PDA) and its influence on a variety of spasmogenic responses in trachea isolated in from normal and sensitized guinea-pigs. Tracheal preparations were denuded of epithelium, treated with indomethacin (2·8 μm), and cooled to 20°C. In these experimental conditions, tracheal strips contracted to PDA (0·1 nm-1 μm). Contractions to PDA (1 μm) were greater in sensitized tissues. In normal trachea, contractions to PDA (0·1 μm) were depressed by H-7, 1-(5-isoquinolinyl-sulphonyl)-2-methylpiperazine, (50 μm), amiloride (10 μm), verapamil (10 μm) and Ca2+-free exposure. Similar effects were obtained in sensitized trachea except that PDA…
The spasmogenic effects of vanadate in human isolated bronchus
1997
1. Inhalation of vanadium compounds, particularly vanadate, is a cause of occupational bronchial asthma. We have now studied the action of vanadate on human isolated bronchus. Vanadate (0.1 microM-3 mM) produced concentration-dependent, well-sustained contraction. Its -logEC50 was 3.74 +/- 0.05 (mean +/- s.e.mean) and its maximal effect was equivalent to 97.5 +/- 4.2% of the response to acetylcholine (ACh, 1 mM). 2. Vanadate (200 microM)-induced contraction of human bronchus was epithelium-independent and was not inhibited by indomethacin (2.8 microM), zileuton (10 microM), a mixture of atropine, mepyramine and phentolamine (each at 1 microM), or by mast cell degranulation with compound 48/…
The effects of phorbol 12,13-diacetate on responses of guinea-pig isolated trachea to methylxanthines, isoprenaline and ryanodine
1994
1. Using guinea-pig isolated trachea, we have studied how phorbol 12,13-diacetate (PDA) modulates mechanical responses of the tissue to methylxanthines, isoprenaline and ryanodine. 2. Caffeine (10 microM-5 mM), theophylline (10 microM-5 mM) and isoprenaline (1 nM-1 microM), each inhibited the spontaneous tone of the trachea. Pretreatment with PDA (0.1-10 microM) converted relaxant responses to high concentrations of the methylxanthines into contractions. PDA produced no equivalent effect against isoprenaline. Pretreatment with verapamil (1 or 10 microM), nifedipine (0.1 microM) or incubation with Ca(2+)-free, EGTA (0.1 mM)-containing physiological salt solution (PSS) suppressed the contract…
Bronchodilator and anti-inflammatory activities of glaucine:In vitrostudies in human airway smooth muscle and polymorphonuclear leukocytes
1999
Selective phosphodiesterase 4 (PDE4) inhibitors are of potential interest in the treatment of asthma. We examined the effects of the alkaloid S-(+)-glaucine, a PDE4 inhibitor, on human isolated bronchus and granulocyte function. Glaucine selectively inhibited PDE4 from human bronchus and polymorphonuclear leukocytes (PMN) in a non-competitive manner (Ki=3.4 μM). Glaucine displaced [3H]-rolipram from its high-affinity binding sites in rat brain cortex membranes (IC50∼100 μM). Glaucine inhibited the spontaneous and histamine-induced tone in human isolated bronchus (pD2∼4.5). Glaucine (10 μM) did not potentiate the isoprenaline-induced relaxation but augmented cyclic AMP accumulation by isopre…
EFFECTS OF VANADATE ON RESPONSES OF GUINEA-PIG ISOLATED TRACHEA TO SPASMOGENS
1993
Abstract The effects of vanadate on the contractility of the guinea-pig isolated trachea was examined. Vanadate (0·1 Mm) produced a sustained contraction that was abolished in Ca2+-free EGTA (0·1 Mm)-containing physiological salt solution but was resistant to verapamil (1 μm). Vanadate (0·1 Mm) depressed tracheal responses to CaCl2 (in Ca2+-free depolarizing solution), KCl, acetylcholine, histamine and 5-hydroxytryptamine. For vanadate (10 μm), the inhibition of spasmogenic responses only reached statistical significance for histamine and 5-hydroxytryptamine. Caffeine (1 Mm)-induced spasm (trachea at 20°C in the presence of indomethacin (2·8 μm)) was not affected by vanadate (10 μm-0·1 Mm).…
Inhibitory effects of N-acetylcysteine on superoxide anion generation in human polymorphonuclear leukocytes.
1997
Abstract It has been suggested that reactive oxygen species released by activated polymorphonuclear leukocytes (PMN) in man is one mechanism of tissue injury. Therapeutic action aimed at increasing antioxidant defence mechanisms is still a clinical challenge. This study examines the activity of N-acetylcysteine, a known antioxidant, in the protection of PMN exposed in-vitro to the chemoattractant peptide fMet-Leu-Phe (FMLP), the protein kinase C activator phorbol myristate acetate or the lipid peroxidation promoter t-butyl hydroperoxide. FMLP (3–300 nm) and phorbol myristate acetate (160 pm–160 nm) induced concentration-related superoxide anion generation. Pre-treatment with N-acetylcystein…
Effects of SCA40 on human isolated bronchus and human polymorphonuclear leukocytes: comparison with rolipram, SKF94120 and levcromakalim
1996
1. SCA40 (0.1 nM-0.1 mM) produced concentration-dependent suppression of the spontaneous tone of human isolated bronchus (-log EC50 = 6.85 +/- 0.09; n = 10) and reached a maximal relaxation similar to that of theophylline (3 mM). The potency (-log EC50 values) of SCA40 compared to other relaxants was rolipram (7.44 +/- 0.12; n = 9) > SCA40 > or = levcromakalim (6.49 +/- 0.04; n = 6) > SKF94120 (5.87 +/- 0.10; n = 9). 2. When tested against the activity of the isoenzymes of cyclic nucleotide phosphodiesterase (PDE) isolated from human bronchus, SCA40 proved highly potent against PDE III (-log IC50 = 6.47 +/- 0.16; n = 4). It was markedly less potent against PDE IV (4.82 +/- 0.18; n = 4) and …