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Mechanisms of nitrogen dioxide toxicity in humans.
Res Rep Health Eff Inst 1991; (43):1-33RR

Abstract

These studies were undertaken to evaluate short-term respiratory effects and identify markers of nitrogen dioxide toxicity during exposures designed to approximate realistic conditions. With the development of bronchoalveolar lavage as a clinical investigative technique, the evaluation focused on the assessment of effects induced at the alveolar level. The exposure protocols were designed to assess the duration of nitrogen dioxide-induced effects and determine exposure-response relationships. Groups of normal, nonsmoking volunteers of both sexes between the ages of 18 and 40 years, without airway hyperreactivity, constituted the study population. The exposure protocols required a total of three to five days for each subject, depending on the timing of bronchoalveolar lavage. Subjects were exposed to nitrogen dioxide or air for three hours in a double-blind, randomized fashion in a 45-m3 environmental chamber, with intermittent exercise sufficient to quadruple minute ventilation. Pulmonary function was measured during and after exposure, and airway reactivity to carbachol was assessed before and after exposure. Lavaged cells were examined for their capacity to inactivate influenza virus and secrete IL-1 in vitro. Cell-free lavage fluid was analyzed for total protein, albumin, alpha 2-macroglobulin, arylsulfatase, and alpha 1-protease inhibitor. The studies were undertaken in three phases, each of approximately one year's duration. In Phase 1, 15 subjects were exposed to a background concentration of 0.05 parts per million2 (ppm) nitrogen dioxide and to three 15-minute peaks of 2.0 ppm, and underwent bronchoalveolar lavage 3.5 hours after nitrogen dioxide exposure. During Phase 2, 8 subjects were exposed to continuous 0.60 ppm nitrogen dioxide and underwent bronchoalveolar lavage 18 hours later. Finally, in Phase 3, 15 subjects were exposed to continuous 1.5 ppm nitrogen dioxide and underwent bronchoalveolar lavage 3.5 hours after exposure. No significant symptomatic or pulmonary function changes could be detected in response to any of the nitrogen dioxide exposures. However, a small but significant increase in airway reactivity was observed in normal subjects after exposure to 1.5 ppm nitrogen dioxide. Following the highest dose of carbachol (10 mg/mL), the forced expiratory volume in one second decreased 7.5 +/- 1.1 percent after nitrogen dioxide exposure compared to 4.8 +/- 1.1 percent after exposure to air (p less than 0.05). No symptoms were induced in any of the groups by the carbachol exposures. Analyses of cells recovered by bronchoalveolar lavage during all three phases revealed no differences in total cell recovery, cell viability, or differential cell counts.(

ABSTRACT

TRUNCATED AT 400 WORDS)

Authors+Show Affiliations

Department of Medicine, University of Rochester School of Medicine and Dentistry, NY 14642.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Clinical Trial
Journal Article
Randomized Controlled Trial

Language

eng

PubMed ID

1930769

Citation

Utell, M J., et al. "Mechanisms of Nitrogen Dioxide Toxicity in Humans." Research Report (Health Effects Institute), 1991, pp. 1-33.
Utell MJ, Frampton MW, Roberts NJ, et al. Mechanisms of nitrogen dioxide toxicity in humans. Res Rep Health Eff Inst. 1991.
Utell, M. J., Frampton, M. W., Roberts, N. J., Finkelstein, J. N., Cox, C., & Morrow, P. E. (1991). Mechanisms of nitrogen dioxide toxicity in humans. Research Report (Health Effects Institute), (43), pp. 1-33.
Utell MJ, et al. Mechanisms of Nitrogen Dioxide Toxicity in Humans. Res Rep Health Eff Inst. 1991;(43)1-33. PubMed PMID: 1930769.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Mechanisms of nitrogen dioxide toxicity in humans. AU - Utell,M J, AU - Frampton,M W, AU - Roberts,N J,Jr AU - Finkelstein,J N, AU - Cox,C, AU - Morrow,P E, PY - 1991/8/11/pubmed PY - 2001/3/28/medline PY - 1991/8/11/entrez SP - 1 EP - 33 JF - Research report (Health Effects Institute) JO - Res Rep Health Eff Inst IS - 43 N2 - These studies were undertaken to evaluate short-term respiratory effects and identify markers of nitrogen dioxide toxicity during exposures designed to approximate realistic conditions. With the development of bronchoalveolar lavage as a clinical investigative technique, the evaluation focused on the assessment of effects induced at the alveolar level. The exposure protocols were designed to assess the duration of nitrogen dioxide-induced effects and determine exposure-response relationships. Groups of normal, nonsmoking volunteers of both sexes between the ages of 18 and 40 years, without airway hyperreactivity, constituted the study population. The exposure protocols required a total of three to five days for each subject, depending on the timing of bronchoalveolar lavage. Subjects were exposed to nitrogen dioxide or air for three hours in a double-blind, randomized fashion in a 45-m3 environmental chamber, with intermittent exercise sufficient to quadruple minute ventilation. Pulmonary function was measured during and after exposure, and airway reactivity to carbachol was assessed before and after exposure. Lavaged cells were examined for their capacity to inactivate influenza virus and secrete IL-1 in vitro. Cell-free lavage fluid was analyzed for total protein, albumin, alpha 2-macroglobulin, arylsulfatase, and alpha 1-protease inhibitor. The studies were undertaken in three phases, each of approximately one year's duration. In Phase 1, 15 subjects were exposed to a background concentration of 0.05 parts per million2 (ppm) nitrogen dioxide and to three 15-minute peaks of 2.0 ppm, and underwent bronchoalveolar lavage 3.5 hours after nitrogen dioxide exposure. During Phase 2, 8 subjects were exposed to continuous 0.60 ppm nitrogen dioxide and underwent bronchoalveolar lavage 18 hours later. Finally, in Phase 3, 15 subjects were exposed to continuous 1.5 ppm nitrogen dioxide and underwent bronchoalveolar lavage 3.5 hours after exposure. No significant symptomatic or pulmonary function changes could be detected in response to any of the nitrogen dioxide exposures. However, a small but significant increase in airway reactivity was observed in normal subjects after exposure to 1.5 ppm nitrogen dioxide. Following the highest dose of carbachol (10 mg/mL), the forced expiratory volume in one second decreased 7.5 +/- 1.1 percent after nitrogen dioxide exposure compared to 4.8 +/- 1.1 percent after exposure to air (p less than 0.05). No symptoms were induced in any of the groups by the carbachol exposures. Analyses of cells recovered by bronchoalveolar lavage during all three phases revealed no differences in total cell recovery, cell viability, or differential cell counts.(ABSTRACT TRUNCATED AT 400 WORDS) SN - 1041-5505 UR - https://www.unboundmedicine.com/medline/citation/1930769/Mechanisms_of_nitrogen_dioxide_toxicity_in_humans_ DB - PRIME DP - Unbound Medicine ER -