title: An evaluation of the inhalation toxicity of one commercial proteolytic enzyme preparation.
abstract: The inhalation toxicity of a commercial proteolytic enzyme preparation containing 12% subtilisin Carlsberg was studied in experimental animals. Guinea pigs that had been pretreated by a series of intradermal injections of the enzyme preparation in saline solution died as a result of a single 6-hour exposure to the enzyme preparation at an air concentraion of 41.2 mg/m-3, while normal guinea pigs and pretreated guinea pigs that were dosed with an antihistamine immediately prior to exposure survived. The 6-hour LC50 for pretreated guinea pigs was determined as 24.7 mg/m-3. Normal rats, normal rabbits, and pretreated rabbits survived exposures to the enzyme preparation at concentrations as high as 36.8 mg/m-3. Pathologic examinations revealed changes only in the lungs of the exposed animals. These pulmonary alterations appear to be reversible. A histamine release is suggested as the primary effect of a secondary exposure to this proteolytic enzyme preparation.
mesh_terms: D000336:Aerosols; D000818:Animals; D001412:Bacillus subtilis / Q000201:enzymology; D004155:Diphenhydramine / Q000627:therapeutic use; D004781:Environmental Exposure; D005069:Evaluation Studies as Topic; D006168:Guinea Pigs; D007271:Injections, Intradermal; D008168:Lung / Q000187:drug effects; D009787:Occupational Medicine; D010447:Peptide Hydrolases / Q000633:toxicity*; D011817:Rabbits; D051381:Rats; D013381:Subtilisins / Q000633:toxicity
chemical_list: D000336:Aerosols; D004155:Diphenhydramine; D010447:Peptide Hydrolases; D013381:Subtilisins