Ozone-induced lung inflammation and mucosal barrier disruption: toxicology, mechanisms, and implications

Bhalla, DK

HERO ID

1239

Reference Type

Journal Article

Subtype

Review

Year

1999

Language

English

PMID

10081525

HERO ID 1239
Material Type Review
In Press No
Year 1999
Title Ozone-induced lung inflammation and mucosal barrier disruption: toxicology, mechanisms, and implications
Authors Bhalla, DK
Journal Journal of Toxicology and Environmental Health, Part B: Critical Reviews
Volume 2
Issue 1
Page Numbers 31-86
Abstract The airway epithelial lining serves as an efficient barrier against penetration of exogenous particles and macromolecules. Disruption of this barrier following O3 exposure represents a state of compromised epithelial defenses leading to increased transmucosal permeability. Although the barrier disruption following an acute exposure is transient in nature, the brief period of disruption caused by O3 an oxidant air pollutant, provides an opportunity for facilitated entry of a potentially toxic particulate copollutant(s) across the airway epithelia. The subsequent deposition and retention of the copollutant(s) in the subepithelial compartment for prolonged periods adds the risk of injury due to chronic exposure following an acute episode. Toxicological studies from several laboratories have demonstrated alterations in epithelial permeability, suggestive of barrier disruption, in animals and humans exposed to O3. Inflammatory cells represent another important component of pulmonary defenses, but upon activation these cells can both induce and sustain injury. The recruitment of these cells into the lung following O3 exposure presents a risk of tissue damage through the release of toxic mediators by activated inflammatory cells. Several studies have reported concomitant changes in permeability and recruitment of the inflammatory cells in the lung following O3 exposure. In these studies, an inflammatory response, as detected by an increase in the number of polymorphonuclear leukocytes in the bronchoalveolar lavage (BAL) or in lung parenchyma, was accompanied by either an increased tracer transport across the airway mucosa or an elevation in the levels of total protein and/or albumin in the BAL. The magnitude of response and the time at which the permeability changes and inflammatory response peaked varied with O3 concentration, exposure duration, and the mode of analysis. The responsiveness to O3 also appeared to vary with the animal species, and increased under certain conditions such as physical activity and pregnancy. Some of the effects seen after an acute exposure to O3 were modified upon repeated exposures. The responses following repeated exposures included attenuation, persistence, or elevation of permeability and inflammation. Mechanistic studies implicate chemotactic factors, cellular mediators, and cell-surface-associated molecules in the induction of inflammation and lung injury. In discussing these studies, this review serves to introduce the mucosal barrier functions in the lung, evaluates inflammatory and permeability consequences of O3 addresses mechanisms of inflammatory reactions, and offers alternate viewpoints.
Doi 10.1080/109374099281232
Pmid 10081525
Wosid WOS:000078069900002
Is Certified Translation No
Dupe Override No
Comments ECRIB.J. Toxicol. Environ. Health Part B 2: 31-86.
Is Public Yes
Language Text English
Is Qa No