Biomaterial Database

Comparative toxicity of methyl isocyanate and its hydrolytic derivatives in rats. I. Pulmonary histopathology in the acute phase. 1994

K Jeevaratnam, and S Sriramachari

Defence Research and Development Establishment, Gwalior, India.

The present study describes the acute histopathological changes induced by methyl isocyanate (MIC) in the lungs of rats at 24 h after a single exposure to varied concentrations/doses of MIC by inhalation and subcutaneous (s.c.) routes and also delineates the effects due to the hydrolytic derivatives of MIC, viz., methylamine (MA) and N,N'-dimethyl urea (DMU). MIC, either inhaled or administered s.c., resulted in a wide range and extent of histopathological changes in the lungs, proportional to the exposure concentration/dose. The salient, effects of inhaled MIC are acute necrotizing bronchitis of the entire respiratory tract accompanied by varying degrees of confluent congestion, hyperemia and interstitial and intra-alveolar edema, while MIC administered s.c. led to prominent vascular endothelial damage, congestion and severe interstitial pneumonitis with apparently normal bronchial epithelium; and intra-alveolar edema only with the high dose. The only noteworthy lesion produced by MA and DMU (to some extent) was interstitial pneumonitis, suggesting their possible involvement in the subsequent inflammatory response of MIC. Except, for the endothelial changes, the overall spectrum of the histopathological lesions is quite comparable to those observed in the lungs of Bhopal victims during the acute phase.

UI	MeSH Term	Description	Entries
D007279	Injections, Subcutaneous	Forceful administration under the skin of liquid medication, nutrient, or other fluid through a hollow needle piercing the skin.	Subcutaneous Injections,Injection, Subcutaneous,Subcutaneous Injection
D008168	Lung	Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.	Lungs
D008297	Male		Males
D008744	Methylamines	Derivatives of methylamine (the structural formula CH3NH2).
D008782	Methylurea Compounds	Urea compounds which are substituted with one or more methyl groups.	Compounds, Methylurea
D008856	Microscopy, Fluorescence	Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye.	Fluorescence Microscopy,Immunofluorescence Microscopy,Microscopy, Immunofluorescence,Fluorescence Microscopies,Immunofluorescence Microscopies,Microscopies, Fluorescence,Microscopies, Immunofluorescence
D009336	Necrosis	The death of cells in an organ or tissue due to disease, injury or failure of the blood supply.
D011654	Pulmonary Edema	Excessive accumulation of extravascular fluid in the lung, an indication of a serious underlying disease or disorder. Pulmonary edema prevents efficient PULMONARY GAS EXCHANGE in the PULMONARY ALVEOLI, and can be life-threatening.	Wet Lung,Edema, Pulmonary,Edemas, Pulmonary,Pulmonary Edemas,Lung, Wet,Lungs, Wet,Wet Lungs
D001991	Bronchitis	Inflammation of the large airways in the lung including any part of the BRONCHI, from the PRIMARY BRONCHI to the TERTIARY BRONCHI.	Bronchitides
D004195	Disease Models, Animal	Naturally-occurring or experimentally-induced animal diseases with pathological processes analogous to human diseases.	Animal Disease Model,Animal Disease Models,Disease Model, Animal