Biological effects of short-term, high-concentration exposure to methyl isocyanate. III. Influence on gas exchange in the guinea pig lung
The influence of methyl isocyanate (MIC) inhalation on the gas exchange function of the lungs in guinea pigs was studied by measuring arterial blood gases, pH, and tracheal pressure during constant-volume, artificial ventilation with air or 100% O/sub 2/ at 40 and 120 min after exposure. A 15 min exposure to MIC at concentrations of 240 to 628 ppm caused a marked reduction in PaO/sub 2/ and pH/sub a/ and an elevated tracheal pressure during artificial ventilation. The low PaO/sub 2/ was only slightly elevated when the animals were ventilated with 100% O/sub 2/. Although the dry-wet lung weight ratio was reduced at the highest exposure concentration, the effect was not severe and no significant increase in lung water was found at the lower concentrations. MIC inhalation caused severe pulmonary blood shunting and ventilation/perfusion imbalance. This, in turn, led to hypoxemia, metabolic acidosis, and tissue hypoxia, which could produce death. The pulmonary gas exchange deficit likely resulted from bronchial and bronchiolar obstruction caused by sloughed epithelium and other debris from intra- and extrapulmonary airways.
- Research Organization:
- Union Carbide Corp., Export, PA
- OSTI ID:
- 6016070
- Journal Information:
- Environ. Health Perspect.; (United States), Vol. 72
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CARBON DIOXIDE
BLOOD CHEMISTRY
ISOCYANATES
BIOLOGICAL EFFECTS
LUNGS
PHYSIOLOGY
OXYGEN
ACUTE EXPOSURE
ANOXIA
GUINEA PIGS
PH VALUE
VENTILATION
WATER
ANIMALS
BODY
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
ELEMENTS
HYDROGEN COMPOUNDS
MAMMALS
NONMETALS
ORGANS
OXIDES
OXYGEN COMPOUNDS
RESPIRATORY SYSTEM
RODENTS
VERTEBRATES
560300* - Chemicals Metabolism & Toxicology