Pulmonary mechanical responses to intestinal ischaemia-reperfusion and endotoxin preconditioning.

During intestinal ischaemia-reperfusion, endotoxin can be translocated. Pretreatment with sublethal doses of endotoxin develops tolerance to ischaemia-reperfusion in different organs; however, the tolerance to intestinal ischaemia-reperfusion in the lung has rarely been investigated. Our aim was to study the role of endotoxin pretreatment in the mechanical responses and inflammatory activation induced by intestinal ischaemia-reperfusion in the lung.

B-lines quantify the lung water content: a lung ultrasound versus lung gravimetry study in acute lung injury.

B-lines (also termed ultrasound lung comets) obtained with lung ultrasound detect experimental acute lung injury (ALI) very early and before hemogasanalytic changes, with a simple, noninvasive, nonionizing and real-time method. Our aim was to estimate the correlation between B-lines number and the wet/dry ratio of the lung tissue, measured by gravimetry, in an experimental model of ALI. Seventeen Na-pentobarbital anesthetized, cannulated (central vein and carotid artery) minipigs were studied: five sham-operated animals served as controls and, in 12 animals, ALI was induced by injection of oleic acid (0.

The involvement of histaminic and muscarinic receptors in the bronchoconstriction induced by myorelaxant administration in sensitized rabbits.

Background: Muscle relaxants cause bronchospasm via histamine release and/or by acting on the muscarinic receptors; we sought to characterize the respective importance of these pathways in the presence of bronchial hyperreactivity.

Methods: Ovalbumin-sensitized rabbits were randomly assigned to several protocol groups: Group C comprised untreated animals; in the other three groups, either H1 and H2 histaminic receptor blockade was performed, leaving the M1, M2, and M3 muscarinic receptors functional (Group M123), or combining this treatment with M3 muscarinic receptor blockade (Group M12), or with vagotomy (Group M3). Respiratory system impedance was measured over a 90-s period, during which succinylcholine, mivacurium or atracurium was administered.

Lung volumes and respiratory mechanics in elastase-induced emphysema in mice.

Absolute lung volumes such as functional residual capacity, residual volume (RV), and total lung capacity (TLC) are used to characterize emphysema in patients, whereas in animal models of emphysema, the mechanical parameters are invariably obtained as a function of transrespiratory pressure (Prs). The aim of the present study was to establish a link between the mechanical parameters including tissue elastance (H) and airway resistance (Raw), and thoracic gas volume (TGV) in addition to Prs in a mouse model of emphysema. Using low-frequency forced oscillations during slow deep inflation, we tracked H and Raw as functions of TGV and Prs in normal mice and mice treated with porcine pancreatic elastase.

The bimodal quasi-static and dynamic elastance of the murine lung.

The double sigmoidal nature of the mouse pressure-volume (PV) curve is well recognized but largely ignored. This study systematically examined the effect of inflating the mouse lung to 40 cm H2O transrespiratory pressure (Prs) in vivo. Adult BALB/c mice were anesthetized, tracheostomized, and mechanically ventilated.