Functional, biochemical, and histopathological evidence of airway obstruction in rats following a four-hour acute inhalation exposure to n-butyl isocyanate.
Pulmonary function, arterial blood gases, acid-base status, and bronchoalveolar lavage fluid (BALF) composition were assessed in male Wistar rats after a single 4-h exposure to 0, 7.6, 23.5 or 55.2 mg n-butyl isocyanate (n-BIC)/m3 air. No significant changes other than transient clinical signs were observed in the rats exposed to 7.6 mg/m3 air. Four weeks after exposure the animals of the 55.2 mg/m3 group showed significant effects: those were pronounced histopathological changes of airways and parenchyma, and elevated relative lung weight. The neutrophils, LDH, and protein in BALF were elevated. Quasi-static lung compliance, peak expiratory flow rate, mean mid expiratory flow rate were decreased whereas lung resistance, residual volume, and single breath CO-diffusing capacity were increased. Blood gas measurements revealed an elevation in hemoglobin, pH, arterio-alveolar oxygen difference, and venous admixture. Arterial pO2 and pCO2 were decreased. In animals exposed to 23.5 mg/m3 only marginal effects were detectable.
Pauluhn
J
J
BAYER AG, Department of Toxicology, Wuppertal, FRG.
Eben
A
A
Kimmerle
G
G
D000136:Acid-Base Equilibrium; D000280:Administration, Inhalation; D000402:Airway Obstruction / Q000139:chemically induced* / Q000473:pathology / Q000503:physiopathology; D000818:Animals; D001273:Atmosphere Exposure Chambers; D001784:Blood Gas Analysis; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry / Q000166:cytology; D003485:Cyanates / Q000008:administration & dosage / Q000633:toxicity*; D005541:Forced Expiratory Volume / Q000502:physiology; D017953:Isocyanates; D008168:Lung / Q000503:physiopathology*; D008297:Male; D011659:Pulmonary Gas Exchange; D051381:Rats; D011919:Rats, Inbred Strains; D012129:Respiratory Function Tests; D013997:Time Factors
D003485:Cyanates; D017953:Isocyanates; C002509:butyl isocyanate