摘要:

4‐Methylphenylhydrazine hydrochloride (4‐MPH) was administered to randomly bred Swiss mice as 26 weekly sc infections of 140 μg per gram of body weight and N'‐acetyl‐4‐(hydroxymethyl)phenylhydrazine (AMPH) as 26 weekly sc injections of 500 μg/g. As o solvent control, physiological saline was also given as 26 weekly sc injections of 0.01 ml/g. The 4‐MPH treatment induced a significant incidence (24%) of fibrosarcomas in males. In the 4‐MPH‐treated females and some AMPH‐treated male mice, a few soft‐tissue tumors were observed; however, their appearance could not be related to treatment.

ISSN:0098-4108    

DOI:10.1080/15287398109530045

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

A method is described for collection of metabolic15N2from in vitro preparations or intact rats administered15N‐containing compounds. The method enables routine collection and mass spectrometric measurement of as little as 10 μmol15N2respired by a rat over a 24‐h period. A device is described that includes either an animal chamber or a tissue reaction vessel in a closed recycling atmosphere, with automatic O2replenishment and removal of CO2and water. It is capable of sustaining moderate vacuum and is coupled to a high‐vacuum manifold designed to process the contained atmosphere and respiratory gases. The starting atmosphere is an 80:20 mix of sulfur hexafluoride and O2. Recovery of15N2gas from the system without an animal present was 101.3 ± 5. 75%. When15N2gas was very slowly infused iv into an animal, recovery was 89.1 ± 5.38%. Use of the method in studies of the fate of [15N]hydrazine in rats indicated that about 15% of the administered hydrazine is rapidly converted to15N2, followed by slower conversion of an additional 7–10% over the next several hours.

ISSN:0098-4108    

DOI:10.1080/15287398109530046

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Studies of the disposition of hydrazine administered to mammals have not succeeded in accounting for more than a modest fraction of the dose, nor have the excretory products been completely identified. We have utilized15N‐labeled hydrazine and conventional methods to account for about 75% of single doses of about 0.5 LD50(1 mmol/ kg). In 48 h, about 30% appeared in urine as hydrazine and about 20% emerged as a derivative that is acid‐hydrolyzable to hydrazine. About 25% was converted to N2gas, most of which appeared less than 30 min after administration. The percentage converted to N2at 4 h increased only slightly with dose between 0.5 and 2.0 mmol /kg. Disappearance of hydrazine from blood was biphasic with half‐times of 0.74 and 26.9 h.

ISSN:0098-4108    

DOI:10.1080/15287398109530047

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Hartley guinea pigs were exposed for 1 h to either NO2gas or H2SO4aerosol and examined for changes in airway responsiveness to inhaled histamine. Concentrations ranged from 7 to 146 ppm NO2and 4 to 40 mg/m3H2SO4. One group of animals exposed to filtered air served as controls. Histamine challenges were performed on unanesthetized animals 2 h before pollutant or air exposure (baseline) and 10 min and 2 and 19 h after exposure. NO2‐exposed animals had increased histamine sensitivities 10 min after exposure, and the magnitude of the increase was directly dependent on the NO2concentration. Most of the NO2‐exposed animals demonstrated a dramatic return toward baseline values by 2 h after exposure; however, several animals had not returned to baseline by 19 h after exposure. Some animals exposed to H2SO4developed severe labored breathing during exposure, and major increases in histamine sensitivity were observed only in those animals. These results suggest that both NO2and H2SO4alter airway sensitivity to histamine, but apparently by different mechanisms. Changes produced by NO2exposures appeared primarily concentration‐dependent, while changes produced by H2SO4exposures appeared related to dyspnea developed during exposure.

ISSN:0098-4108    

DOI:10.1080/15287398109530048

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Sixty‐day‐old wale, specific pathogen‐free rats were exposed continuously to 5 or 15 ppm NO2for 1–7 d. Lung tissue from exposed and control rats was then analyzed for biochemical and enzymatic parameters. The exposure resultedin increased lung enzymatic activities, including elevated protein and DNA contents andnonprotein sulfhydryl levels. Biochemical and enzymatic paramters generally increased maximally after 4 d and remained elevated for up to 7 d of continued exposure. The magnitude of these increases was higher for 15 than for 5 ppm NO2. The increases in biochemical and enzymatic parameters may have occurred in response to NO2‐induced lung injury.

ISSN:0098-4108    

DOI:10.1080/15287398109530049

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Subacute inhalation experiments were conducted to determine the LC50 value for adult Sprague‐Dawley rats exposed to iodoform vapor. Each dose consisted of 5 males and 5 females that were together fora 7‐h exposure or sham exposure and then separated for observation over the subsequent 24‐h period. The rats were deprived of food and water during actual exposure or sham exposure. Exposures were conducted in a custom‐designed 75–1 glass chamber. Vapor concentrations were verified in samples taken from the exposure chamber. Under the conditions of the experiments the 7‐h LC50 was found to be 183 ppm. The second objective of these experiments was to determine the toxic effects of iodoform vapor on rats exposed for 7 h/d for 7 consecutive days. Three groups of 5 young adult male and 5 female rats were used. One group served as a sham control and the other groups were exposed to 1 and 14 ppm iodoform vapor. No significant differences were noted in food and water intake, urine and feces output, and intestinal transit performance in either exposed group. No remarkable changes were noted in SMA 12/60 blood values for either exposed group. The only histopathological manifestation noted was the presence of mineralized deposits in the medullary renal tubules of some of the rats from the 14‐ppm group.

ISSN:0098-4108    

DOI:10.1080/15287398109530050

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Acute inhalation experiments were conducted to determine 24‐h LC50 values for adult Sprague‐Dawley rats of both sexes exposed to vapors of methyl mercaptan and other reduced‐S compounds for 4‐h periods. Using calculated gas concentrations, the following LC50 value for each gas and combination was determined: methyl mercaptan, 675 ppm; dimethyl sulfide, 40,250 ppm;dimethyl disulfide, 805 ppm;hydrogen sulfide, 444 ppm; and an equimolar mixture of methyl mercaptan, dimethyl sulfide, and dimethyl disulfide, 550 ppm. The effects on body and tissue weights, gross metabolic performance, O2consumption, systolic blood pressure, various blood parameters, and intestinal transit time associated with 3‐mo exposures of young adult male rats to chemically verified concentrations of 2, 17, and 57 ppm methyl mercaptan vapor are summarized in this report. No mortality was experienced by any group. Histopathological findings were essentially nil except for microscopic suggestions of liver damage. The most readily apparent phenomenon was the decrease in body weight. Average values of terminal body weights for all exposed groups were lower than that for the sham control group. This difference was significant in the 57 ppm group and followed a statistically significant dose‐related trend.

ISSN:0098-4108    

DOI:10.1080/15287398109530051

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Levels of elastase activity in homogenates of pancreas from beagle dogs exposed to cigarette smoke on a daily basis for 600 d were previously reported. Elastase activity in pancreatic homogenates from animals exposed to smoke from high‐nicotine cigarettes was significantly greater than in sham‐exposed controls or in animals smoking lownicotine cigarettes.

ISSN:0098-4108    

DOI:10.1080/15287398109530052

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Urine samples from a control population and from a population of chemical workers from two chemical plants near Florence, Italy, were analyzed for the presence of mutagenic chemicals by theSalmonella/microsome test. When tested with strain TA 1538, the urine of nonsmoking chemical workers showed higher mutagenic activity than that of controls in the presence of invitrometabolic activation, but no difference was found between controls and chemical workers who both smoked. Increased mutagenic activity was observed in the group of control smokers compared to control nonsmokers, but the same effect was not observed for chemical workers. When TA 100 was used as the tester strain, the chemical workers, both smoking and nonsmoking, had significantly higher mutagenic activity than controls. The mutagenic activity fell to control levels in some workers’ urine after 20 d leave. Although some perturbing effects of smoking habits were observed, the results seemed to indicate the usefulness of the Salmonella/ microsome test for detection of mutagens in human urine. The results also suggest that people exposed to potentially carcinogenic chemicals may show high enough traces of those chemicals and/or their metabolites in their body fluids to be detected with current mutagenesis techniques.

ISSN:0098-4108    

DOI:10.1080/15287398109530053

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Chloroform (CHCI3) produces renal and hepatic damage in humans and experimental animals. Deuterium‐labeled chloroform (CDCI3) has been reported to be less hepatotoxic than CHCI3in rats. However, this isotope effect has not been determined in other species or in extrahepatic tissues. In this investigation, the effect of deuterium substitution on the nephrotoxicity and hepatotoxicity of CHCI3was quantified in male ICR mice. Renal and hepatic damage were determined 24 h after administration of various doses of CHCI3or CDCI3. Liver damage was estimated by measuring serum glutamic‐pyruvic transaminase (SGPT) activity. Nephrotoxicity was evaluated by measuring blood urea nitrogen (BUN) and in vitro renal cortical accumulation of p‐aminohip‐purate (PAH) and tetraethylammonium (TEA). Dose‐related hepatotoxicity and nephrotoxicity were observed after administration of CHCI3and CDCI3. CDCI3produced less liver damage than CHCI3in mice, suggesting that mouse liver metabolizes CHCI3by the same mechanism as rat liver. CDCI3was also less toxic to kidneys than CHCI3, suggesting that the kidney may metabolize CHCI3in the same marineras the liver.

ISSN:0098-4108    

DOI:10.1080/15287398109530054

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor