  Comparison between Pulmonary Resistance and Penh in Anaesthetised Rats with Tracheal Diameter Reduction and after Carbachol Inhalation; ; et al in Journal of Pharmacological & Toxicological Methods (2005), 51(2, Mar-Apr), 123-128 Introduction: Single-chambered barometric whole-body plethysmography is frequently used as a noninvasive lung function test. However, the validity of the enhanced Pause (Penh), an index of airflow ... [more ▼] Introduction: Single-chambered barometric whole-body plethysmography is frequently used as a noninvasive lung function test. However, the validity of the enhanced Pause (Penh), an index of airflow limitation, remains controversial. We compared Penh with pulmonary resistance (R(L)) to test whether Penh detects tracheal subobstruction and carbachol-induced airflow limitation in spontaneously breathing, anaesthetised rats. Methods: Fourteen male Sprague-Dawley rats underwent tracheal catheterisation, followed by measurements of R(L) and Penh. Six rats underwent tracheal subobstruction by the consecutive insertion into the lumen of the tracheal tube of two catheters of decreasing diameter. Eight rats received an inhaled saline challenge, followed by two noncumulative nebulizations of carbachol (1.25 mg/mL, 1 min). Results: In rats with tracheal calibre reductions, R(L) significantly increased at each reduction (0.218+/-0.052 vs. 0.417+/-0.058 vs. 0.820+/-0.258 cm H(2)O/mL s, p<0.05), whereas Penh only increased after the last reduction (1.88+/-0.25 vs. 2.47+/-0.26, p<0.05). Increases (Delta) of R(L) and Penh were not correlated. In comparison to postsaline values, carbachol induced a significant increase of Penh (1.93+/-0.44 vs. 4.05+/-1.45, p<0.005) and R(L) (0.137+/-0.04 vs. 0.284+/-0.084 cm H(2)O/mL.s, p<0.005). DeltaPenh and DeltaR(L) were significantly correlated (r=0.80, p<0.05). Discussion: This study showed, by comparing Penh with R(L), that single-chambered plethysmography measuring Penh allows to detect carbachol-induced airflow limitation in spontaneously breathing, anaesthetised Sprague-Dawley rats, but poorly detects an increase in R(L) due to tracheal calibre reductions. These findings suggest that Penh might be only be used as an index of airflow limitation under well-defined experimental conditions. [less ▲] Detailed reference viewed: 20 (4 ULg)Charakteriseiring des bronchialen remodelligs in eimen model von felinem asthma; ; et al Conference (2004) Detailed reference viewed: 18 (0 ULg)Cadmium-induced lung inflammation in rats is associated with an increase of matrix metalloproteinases-2 and -9 activity in broncho-alveolar lavage fluid; ; et al in Pflügers Archiv : European Journal of Physiology (2004), 447 Detailed reference viewed: 8 (0 ULg)Whole body barometric plethysmography: a screening method to investigate airway reactivity and acute lung injuries in freely moving pigs; ; et al in Veterinary Journal (2004), 168 The aim of this work was to investigate whether the Penh index, measured using whoie body barometric piethysmography, can be used as a screening parameter to evaluate the airway reactivity and the ... [more ▼] The aim of this work was to investigate whether the Penh index, measured using whoie body barometric piethysmography, can be used as a screening parameter to evaluate the airway reactivity and the intensity of the pulmonary response to endotoxins. Penh was firstly recorded in non-sedated freeiy moving piglets exposed (1) to a nebulized acetylchoiine (Ach) pre-treated or not with cienbuterol, or (2) to endotoxin challenge. To measure Penh simultaneously with total pulmonary resistance (RL), dynamic compliance (cd1) and intrapleural pressure changes (MaxPpl), an oesophageal balloon catheter technique was used and the piglets were anaesthetised. The recordings were performed during (1) an intravenous metacholine (Mch) challenge and (2) in endotoxin-exposed animais. In freely moving animais, Ach induced a significant dose-dependent increase in Penh, which was significantly blocked by clenbuterol. Endotoxin instillation aiso resulted in a significant rise in Penh while the corresponding response measured under anaesthesia was signiflcantly and positively correlated with RL and MaxzPpi. Similar results were obtained during Mch challenge but the Penh was negatively correlated with Cd. We conclude that Penh could be used in freely moving piglets as a screening index for airway reactivity and pulmonary functional changes in cholinergic and endotoxin challenges [less ▲] Detailed reference viewed: 37 (1 ULg)Cadmium-induced oxidative stress and lung emphysema in rats; ; et al in Prostaglandins, Leukotrienes, and Essential Fatty Acids (2004), 71 Detailed reference viewed: 6 (0 ULg)Hydrogen peroxyde in breath condensate as marker of lower airway inflammation in an experimental model of feline asthma; ; et al Conference (2003) Detailed reference viewed: 4 (0 ULg)Increased hydrogen peroxide in breath condensate after aero-allergen challenge in ascaris-suum sensitived cats; ; et al Conference (2003) Detailed reference viewed: 16 (0 ULg)Effect of polystyrene particles on lung mirovascular permeability in isolated perfused rabbit lungs : role of size and surface proporties; ; et al in Toxicology and Applied Pharmacology (2003), 190 Detailed reference viewed: 16 (1 ULg)Role of Substance P and Tachykinin Receptor Antagonists in Citric Acid-Induced Cough in Pigs; ; et al in European Journal of Pharmacology (2000), 408(3), 305-312 The purpose of this work was to investigate the role of tachykinins in cough induced by citric acid (0.8 M) in pigs. With this object, we have studied the effect of citric acid on substance P content in ... [more ▼] The purpose of this work was to investigate the role of tachykinins in cough induced by citric acid (0.8 M) in pigs. With this object, we have studied the effect of citric acid on substance P content in the tracheo-bronchial tree and the effects of substance P and of tachykinin receptor antagonists on citric acid-induced cough. Citric acid exposure significantly increased substance P concentration in both broncho-alveolar and tracheal lavage fluids, while it decreased significantly the substance P content in tracheal mucosa. Substance P did not elicit cough, but significantly potentiated the citric acid-induced cough frequency. Tachykinin NK(1), NK(2) or NK(3) receptor antagonists, SR 140333 (nolpitantium), SR 48968 (saredutant) and SR 142801 (osanetant), respectively, significantly inhibited citric acid-induced cough. The same inhibitory effect of tachykinin receptor antagonists was observed, when substance P was nebulised before citric acid challenge. We conclude that citric acid induces in pigs a release of substance P in the tracheo-bronchial tree, which plays a sensitising role on the cough reflex. The involvement of tachykinin NK(1), NK(2), NK(3) receptors are also demonstrated in this reflex. [less ▲] Detailed reference viewed: 8 (1 ULg) |
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