American journal of respiratory and critical care medicine
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Am. J. Respir. Crit. Care Med. · Jun 1995
Mechanisms and modulation of airway plasma exudation after direct inhalation of cigarette smoke.
We characterized plasma exudation induced by direct inhalation of cigarette smoke in anesthetized, artificially ventilated guinea pigs, using Evans blue dye as a plasma marker, and investigated the neurogenic mechanisms underlying the response. Cigarette smoke increased plasma exudation in the lower trachea, main bronchi, and proximal intrapulmonary airways in a dose-related manner. Exudation was rapid in onset and was maintained for 0.5 to 2 h, depending upon airway level. ⋯ Inhibition by morphine, but not that by nedocromil sodium, was reversed by naloxone. Thus, direct inhalation of cigarette smoke induces a dose-related, long-lasting increase in airway plasma exudation that is due to vapor-phase activation of sensory-efferent nerves, release of sensory neuropeptides that mediate the exudative response via interaction with substance P receptors, and regulation by neutral endopeptidase. The inhibitory effect of nedocromil and morphine on cigarette smoke-induced airway plasma exudation occurs through inhibition of neurotransmission.