Computer assisted recognition and quantitation of the effects of airborne chemicals acting at different areas of the respiratory tract in mice

Abstract

The pattern and timing of a normal breath in unanesthetized mice was analyzed from measurement of inspiratory and expiratory airflows (VI and VE). Airflow was measured via a differential pressure transducer, attached to a pneumotachograph, which itself was attached to a body plethysmograph into which a mouse was placed. The analog voltage from the differential pressure transducer was digitized and stored for analysis on a microcomputer. Criteria were developed to classify each breath as normal (N) or belonging into one of seven abnormal categories. The abnormal categories were arrived at by computer analysis, recognizing specific modifications of the normal pattern into patterns of: sensory irritation of the upper respiratory tract (S), airflow limitation within the conducting airways of the lungs (A) or pulmonary irritation at the alveolar level (P). Combinations of these effects, i.e., S+A, P+A, P+S and P+S+A were also recognized. Computer analysis of each breath also permitted quantitative evaluation of the degree of S, A or P abnormalities. To induce each type of effect we used inhalation exposures to 2-chlorobenzylchloride, carbamylcholine or propranolol. We propose that this approach will permit rapid evaluation of the possible effects of airborne chemicals at three levels of the respiratory tract, with the classification of the type of effect easily obtained in an objective way using well defined criteria, followed by quantitation of the degree of each effect.

Respiratory Effects in Mice Exposed to Airborne Emissions fromStachybotrys chartarumand Implications for Risk Assessment

“…In this case, there was a small variation for individual animals. As a whole, little change occurred over time in the control groups exposed to clean air, a fact which has been observed previously (Vijayaraghavan et al 1994;Boylstein et al 1995Boylstein et al & 1996. Values for I-propanol used here.…”

“…We studied the acute effects of Xchartarum o n the upper respiratory tract and the lungs, using a computerized bioassay in mice (Vijayaraghavan et al 1993(Vijayaraghavan et al & 1994Boylstein et al 1995Boylstein et al & 1996 which takes into account three types of effects. One is the direct stimulation of the trigeminal nerve endings of the upper respiratory tract, termed "sensory irritation" (Alarie 1973).…”

Keratinocyte growth factor protects against Clara cell injury induced by naphthalene

“…Head-out body plethysmography was used to assess the effects of airborne chemicals on respiratory function [44]. The present study demonstrated for the first time that acute airway epithelial damage caused by NA was associated with significant airway dysfunction, indicating that the highly specific injury to Clara cells resulted in significant functional impairment at the organ level.…”

Induction of Prolonged Asthma Tolerance by IL-10–Differentiated Dendritic Cells: Differential Impact on Airway Hyperresponsiveness and the Th2 Immunoinflammatory Response

“…Doubling doses of nebulized methacholine aerosols (0.75-25 mg/ml) were delivered to the head compartment of the plethysmograph, and bronchoconstriction data were gathered as running 1 s means of the airflow at the 50% point in the expiratory cycle (Flow@50%TVe1). This parameter accurately reflects bronchiolar constriction, as opposed to alveolar constriction or airway occlusion (23), and has been shown to correlate well with invasive measurements of AHR (24,25).…”