Journal of pharmacological and toxicological methods
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J Pharmacol Toxicol Methods · Aug 1998
A rat model of acute respiratory distress syndrome (ARDS): Part 1. Time dependency of histological and pathological changes.
The time course of histopathological changes in a rat lung lavage model of the acute respiratory distress syndrome (ARDS) was analyzed by sacrificing animals 10, 30, 60, 180, and 210 min after the last lung parenchyma lavage which was performed with physiological saline solution. This lavage depleted the lung from its natural surfactant resources leading into a pathophysiological cascade similar to that of the acute respiratory distress syndrome. Tracheotomized rats (12 animals per time point) were pressure-controlled ventilated (Siemens Servo Ventilator 900C) with 100% oxygen at a respiratory rate of 30 breaths/min, inspiration-expiration ratio of 1:2, peak inspiratory pressure of 28 cm H2O at positive end-expiratory pressure (PEEP) of 8 cm H2O. ⋯ The rat lavage model shows similarities to the pathophysiological sequelae occuring during the acute phase of the acute respiratory distress syndrome in humans. Most of the characteristic pathognomic histological changes seen in humans can be observed in this lung lavage model. This ARDS model is brief and easy in its experimental design, showed a good and homogeneous reproducibility of pathophysiological and histopathological parameters, and is therefore a useful model to estimate the influence of therapeutic pharmacological treatments of ARDS.
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J Pharmacol Toxicol Methods · Aug 1994
A surgically implantable nerve irrigation system for intermittent delivery of dissolved drugs: evaluation of long-term performance and histocompatibility in rats.
A surgically implantable system designed to facilitate intermittent delivery of solutions of local anesthetic or other pharmacologically active substances to a segment of peripheral nerve was developed and its long-term performance and histocompatibility were tested in rats. Twenty-two systems, each comprising a subcutaneous injection port, a silicone conduit, and a membranous perineural sheath, were implanted in 20 animals. Of the systems, 12 could be used to perform repeated local anesthetic nerve blocks for periods lasting from several weeks to as long as 13 months. The system is suitable for use in studies of peripheral nerve pharmacology and, with improvements, could find clinical use in the management of peripheral neuralgia.
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J Pharmacol Toxicol Methods · Apr 1992
A sciatic nerve blockade method to differentiate drug-induced local anesthesia from neuromuscular blockade in mice.
This report introduces a simple and easy technique for animal handling and drug administration into the sciatic nerve area for determining local anesthesia and neuromuscular blocking activity in mice. The drugs were injected into the popliteal space of the right hindlimb (i.e., the sciatic nerve area). The loss of motor activity of the right hindlimb was taken as a sign of producing local anesthesia. ⋯ The method reported here has been validated by reference neuromuscular blocking agents (d-tubocurarine, decamethonium, and succinylcholine). A positive neuromuscular blockade was recorded when a mouse was unable to stay on the inverted wire mesh screen. The information provides not only the local anesthetic or neuromuscular blocking potency of drugs but also duration of action of drugs.