ABSTRACT
Male and female Fischer 344 rats were exposed to 0-, 3000-, 6500-, or 10,000-ppm n-hexane vapors 6 hr per day, 5 days per week, for 13 weeks. The 13-week exposures had no adverse effect on the growth of female rats. However, the mean body weight gain of male rats in the 10,000-ppm group was significantly lower than for controls at 4 weeks of exposure and thereafter. In addition to the depression of body weight gain, the male exposed to 10,000 ppm had slightly but significantly lower brain weights at necropsy. No adverse testicular effects were noted. Axonopathy was observed in the tibial nerve in four of five male rats from the 10,000-ppm group and one of five male rats in the 6500-ppm group and in the medulla from one male rat in the 10,000-ppm group. These axonal changes were detectable only in teased nerve fiber preparations or in Epon embedded specimens. Histopathologic studies on Formalin fixed tissues did not reveal any lesions that were attributed to n-hexane exposure.
Subject(s)
Hexanes/toxicity , Nervous System Diseases/chemically induced , Air/analysis , Animals , Body Weight/drug effects , Female , Gases , Hexanes/analysis , Hydrogen-Ion Concentration , Male , Nervous System Diseases/pathology , Organ Size/drug effects , Rats , Rats, Inbred F344ABSTRACT
Male and female Fischer 344 rats were exposed to 0, 1250, 2500, or 5000 ppm methyl ethyl ketone (MEK) vapors 6 hours per day, 5 days per week for 90 days. The 90-day exposures had no adverse effect on the clinical health or growth of male or female rats except for a depression of mean body weight in the 5000 ppm exposure group. The 5000 ppm animals had a slight but significant increase in liver weight, liver weight/body weight ratio, and liver weight/brain weight ratio at necropsy. Serum glutamicpyruvic transaminase (SGPT) activity in the 2500 ppm female rats was elevated while the 5000 ppm female rats exhibited significantly decreased SGPT activity. In addition, alkaline phosphatase, potassium and glucose values for the 5000 ppm female rats were increased. Special neuropathological and routine pathological studies did not reveal any lesions that could be attributed to MEK exposure.
Subject(s)
Butanones/toxicity , Air/analysis , Animals , Atmosphere Exposure Chambers , Body Weight/drug effects , Butanones/analysis , Eating/drug effects , Female , Male , Rats , Rats, Inbred F344 , Sex FactorsSubject(s)
Aluminum Hydroxide/pharmacology , Body Weight/drug effects , Organ Size/drug effects , Adrenal Glands/anatomy & histology , Aerosols , Alum Compounds/metabolism , Aluminum Hydroxide/administration & dosage , Animals , Brain/anatomy & histology , Guinea Pigs , Heart/anatomy & histology , Kidney/anatomy & histology , Lung/anatomy & histology , Rats , Spleen/anatomy & histologyABSTRACT
Rats and guinea pigs were exposed to 0.5 ppm ozone, 10 mg/m3 sulfuric acid mist, or their combination for 6 hrs/day, 5 days/week for six months. Exposure-related microscopic alterations were seen in the lungs of guinea pigs exposed to ozone alone or in combination with sulfuric acid mist. No other microscopic lesions were present in either rats or guinea pigs. No biologically meaningful synergistic effects were noted in animals exposed to the combination of ozone and sulfuric mist.
Subject(s)
Ozone/toxicity , Sulfuric Acids/toxicity , Aerosols , Animals , Body Weight/drug effects , Drug Interactions , Female , Guinea Pigs , Male , Ozone/administration & dosage , Rats , Respiratory System/drug effects , Respiratory System/pathology , Species Specificity , Sulfuric Acids/administration & dosage , Time FactorsABSTRACT
Guinea pigs were exposed inhalation chambers to 25 mg/m3 sulfuric acid mist 6 h/d for 2 d, and the acute respiratory effects were correlated by light and electron microscopy. This concentration of acid was selected since lower concentrations result in only slight effects while higher concentrations result in death. By light microscopy, the most prominent pulmonary lesion at 48 h was segmental alveolar hemorrhage and edema accompanied by proliferation of alveolar macrophages and type 2 pneumocytes. The segmental distribution of the pulmonary lesion was reaffirmed by scanning electron microscopy, while transmission electron microscopy showed injury to the distal airways and changes in the vascular endothelium.
Subject(s)
Respiratory Tract Diseases/chemically induced , Sulfuric Acids/pharmacology , Aerosols , Animals , Female , Guinea Pigs , Macrophages/drug effects , Male , Pulmonary Alveoli/ultrastructure , Respiratory System/pathology , Respiratory System/ultrastructureABSTRACT
Rats and guinea pigs were exposed to 0.5 ppm O3, 10 mg/m3 sulfuric acid (H2SO4) mist, or their combination for 6 h/d, 5 d/wk for 6 mo. Microscopic alterations were seen in the lungs of guinea pigs exposed to O3 alone or in combination with H2SO4 mist. No other microscopic lesions were present in either rats or guinea pigs. No biologically meaningful synergistic effects were noted in animals exposed to the combination of O3 and H2SO4 mist.
Subject(s)
Ozone/pharmacology , Sulfuric Acids/pharmacology , Aerosols , Animals , Body Weight/drug effects , Bronchi/pathology , Drug Interactions , Female , Guinea Pigs , Lung/pathology , Male , Organ Size/drug effects , Rats , Sex Factors , Time FactorsABSTRACT
Groups of rats and guinea pigs were exposed, by inhalation, to 0.25, 2.5, and 25 mg/m3 of aluminum chlorhydrate (ACH) for six months to study the effects of a common component of antiperspirants. Similar groups of animals of both species exposed to clean air served as controls. The ACH was generated as a particulate dust using a Wright dust feed mechanism. After six months of exposure, animals were sacrificed. Decreases in body weight were seen in rats exposed to 25 mg/m3 of ACH. Marked increases in lung weights and significant increases in lung to body weight ratios were seen in rats and guinea pigs exposed to 25 mg/m3 of ACH. The lungs of all rats and guinea pigs showed significant dose-related increases in aluminum accumulation when exposed to either 0.25, 2.5, or 25 mg/m3 of ACH. The lungs of all rats and guinea pigs exposed to either 2.5 or 25 mg/m3 of ACH contained exposure-related granulomatous reactions characterized by giant vacuoled macrophages containing basophilic material in association with eosinophilic cellular debris.
Subject(s)
Aluminum/toxicity , Aerosols , Aluminum/metabolism , Animals , Body Weight/drug effects , Female , Guinea Pigs , Lung/pathology , Male , Organ Size/drug effects , Particle Size , Powders , Rats , Rats, Inbred F344 , Time FactorsABSTRACT
Ozone and the oxides of sulfur are common environmental pollutants. The acute pulmonary lesions caused by ozone and sulfuric acid mist in rats and guinea pigs have been characterized. Rats are not affected by sulfuric acid mist in concentrations up to 100 mg/m3 except for reduced body weight at the higher doses. A true alveolitis develops in guinea pigs exposed to more than 20 mg/m3 sulfuric acid mist. The ozone lesion is primarily confined to the terminal bronchioles and proximal alveoli. In combination studies with up to 2 ppm ozone and up to 10 mg/m3 sulfuric acid mist, the pulmonary lesion and lung/body weight data were essentially the same as in exposure to ozone alone, and the number of statistically significant synergistic effects in rats and guinea pigs was about what one would expect to observe by chance alone.
Subject(s)
Ozone/toxicity , Sulfuric Acids/toxicity , Aerosols , Animals , Body Weight/drug effects , Drug Synergism , Guinea Pigs , Male , Organ Size/drug effects , Ozone/administration & dosage , Pulmonary Alveoli/pathology , Rats , Species Specificity , Sulfuric Acids/administration & dosage , Time FactorsABSTRACT
The hygroscopic nature of sulfuric acid mist has not been totally appreciated in previous toxicological work. Sulfuric acid mist, by adsorption or desorption of water, equilibrates rapidly with the relative humidity of its environment. The measured particle diameters of a given sulfuric acid mist will increase in size as the particles adsorb water on entering the respiratory tract. For a dry climate of 5% relative humidity, sulfuric acid mist particles will triple in size in the respiratory tract. At 60% relative humidity, particles will double in size, while particles in humid regions will increase very little. In the respiratory tract, the particles will deposit according to their size at 98% relative humidity. In order to compare toxicity data for sulfuric acid mist, relative humidity must be carefully recorded throughout the experimental procedure.
