摘要:

This report describes the design and construction of a metabolism cage that allows for separation of urine and feces and for trapping expired CO2. Such a cage could find use in pharmacokinetic studies of drug excretion rates where potential metabolism to CO2should be considered. To demonstrate the separation qualities of this cage design, the radioactivity appearing in the urine, feces, and exhaust gases was determined daily for 14 days after the single oral administration of 26‐[14C]cholesterol. Less than 1% of the administered radioactivity appeared in the urine, whereas 61% appeared in the feces and 19% in the expired CO2.

ISSN:0098-4108    

DOI:10.1080/15287397709529570

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

The biological effects of repeated exposures to acrolein (CH2=CHCHO) vapor combined with either intratracheal instillation of benzo[a]pyrene (BP) or subcutaneous injection of diethyinitrosamine (DENA) were examined in an 81 wk study with Syrian golden hamsters. The hamsters, 252 males and 252 females, were evenly distributed over two inhalation chambers, one chamber for air exposure and the other for exposure to 4.0 ppm (9.2 mg/m3) acrolein, 7 hr/day, 5 days/wk, for a period of 52 wk. Equal numbers of animals in each chamber were treated with BP, DENA, or 0.9% NaCI solution. Observations were made of general appearance, body weight, mortality, hematological and biochemical factors, organ weights, and gross and microscopic pathology. At the end of the treatment period (wk 52) 6 animals of each sex per chamber not treated with BP or DENA were killed and extensively examined. The remaining hamsters were killed after 81 wk and examined only for changes in the respiratory tract. Exposure to acrolein resulted in abnormal behavior; growth retardation; increases in hemoglobin content, packed cell volume, and relative lung weight; decreased relative liver weight; and rhinitis accompanied by hyper‐ and metaplasia of the epithelium in the nasal cavity. There was no indication of a carcinogenic activity of acrolein. Respiratory tract tumors were found in males and females treated with BP or DENA. The types of tumors found were those usually seen in hamsters following administration of these carcinogens. Indications of an enhancing effect of acrolein on BP carcinogenesis were doubtful. The carcinogenic effect of DENA on the respiratory tract appeared not to be influenced by exposure to acrolein vapor. It was concluded that the study produced insufficient evidence to enable acrolein to be regarded as an evident cofactor in respiratory tract carcinogenesis.

ISSN:0098-4108    

DOI:10.1080/15287397709529571

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

The retention and tissue distribution of210Pb were studied in 10‐day‐old, 150‐day‐old, and adult monkeys. Lead‐210 nitrate was administered to the monkeys by gavage after a 12 hr fast and210Pb excreted in urine and feces was monitored for 96 hr. All monkeys were necropsied 96 hr after dosing and the210Pb concentration of various tissues was determined. The data demonstrated that infant monkeys retained 64.5 and 69.8% of the orally administered210Pb at 70 and 150 days of age, respectively, while adult monkeys retained 3.2% of the210Pb dose. Blood210Pb levels 96 hr after dosing did not vary significantly between age groups. Of the210Pb contained in blood, 98–99% was found in blood cells and 1–2% in blood plasma; 5–8% of the Pb in blood cells was bound to blood cell membranes. None of these parameters varied significantly with age. The percentage of the lead dose excreted in urine did not vary significantly between age groups. Analysis of tissues for210Pb revealed that both the tissue Pb concentrations and tissue Pb:blood Pb ratios were significantly higher in the bone structure of infants than adults. Brain Pb:blood Pb ratios were significantly greater in 10‐day‐old infants than 150‐day‐old infants or adults.

ISSN:0098-4108    

DOI:10.1080/15287397709529572

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

Benzenesulfonic acid [(3‐amino‐2,4,6‐trichlorophenyl)methylene] hydrazide, a candidate rodenticide coded as DRC‐4575, was administered by gavage to pregnant female BALB/c mice. Each dose (5.5, 28.0, 42.0, 62.0, and 94.0 mg/kg) was given to one of five groups of ten mice on day 8 of gestation, making a total of five different dose groups on day 8. This same procedure was followed for days 9, 10, 11, 12, and 13. This made a total of 30 dose‐day treatment groups. Six control females were dosed each day. Dam survival to day 18 declined as the dose increased; only 2% of the dams survived at 94 mg/kg. When the surviving females were killed at day 18, no significant differences were found between treatment and control animals in the number or weight of live fetuses, or in the ratio of male to female fetuses. However, the percentage of live fetuses was significantly lower and the number of resorptions was significantly higher for the treated dams at the 62 mg/kg dose level than for the control dams. Skeletal anomalies were limited primarily to unossified phalanges, which were probably related to the lower weights of those fetuses. Slight hydrocephalus occurred infrequently at all dose levels and in the controls, and was not dose‐related. These data indicate that DRC‐4575 would be embryotoxic only at doses of 62 mg/kg or higher and would not be teratogenic.

ISSN:0098-4108    

DOI:10.1080/15287397709529573

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

The effect of tin on the calcium binding activity in renal cortex was studied in rats administered stannous chloride intraperitoneally. The calcium concentration in the soluble fraction of renal cortex was elevated about 30‐fold over that in controls 2 days after administration of tin (3.0 mg/100 g). The calcium binding activity in the soluble fraction of renal cortex increased significantly at any of the time intervals between 6 and 72 hr after administration of tin, and this increase preceded an elevation of the calcium concentration in the renal cortex. The increased calcium binding activity produced by administration of tin was strikingly reduced by treatment with actinomycin D (100 μg/100 g). A significant increase in calcium binding activity was not exhibited after administration of zinc, manganese, calcium, or lead. These results suggest that the calcium accumulation in the renal cortex caused by administration of tin is closely connected with an increase in calcium binding activity.

ISSN:0098-4108    

DOI:10.1080/15287397709529574

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

A group of rats were stressed by placing them in a crowded environment. Examination of the hearts showed the following anatomic changes: (1) increased weight; (2) occlusion of capillaries by platelet thrombi; (3) endothelial swelling of capillaries; and (4) swelling and deformity of mitochondria.

ISSN:0098-4108    

DOI:10.1080/15287397709529575

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

Overt clinical disease from undue lead exposure has become a relatively rare phenomenon in adult populations. However, exposure situations that may result in subclinical disease are not uncommon in various occupational settings.

ISSN:0098-4108    

DOI:10.1080/15287397709529576

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

Diethylstilbestrol (DES) is considered a teratogen and a transplacental carcinogen in humans. In order to compare its biotransformation in nonhuman primates to that in humans, a metabolic study was carried out in rhesus monkeys and chimpanzees. After an oral dose of 1 mg/kg [14C]DES, approximately 59% of the ingested radioactivity was found in the urine and 28% in the feces of two female rhesus monkeys after 4 days, while in male rhesus monkeys urinary radioactivity accounted for 43% and fecal radioactivity for 35%. In chimpanzees, 63% of a 0.5 mg/kg dose was excreted with the urine in a female and 47% in a male animal. In both species, urinary radioactivity was predominantly (> 70%) associated with glucuronides. Besides DES, three metabolites were found in the urinary glucuronide fraction of rhesus monkeys and chimpanzees by radio gas chromatography and were identified as dienestrol and ω‐hydroxy derivatives of DES and dienestroi. Fecal radioactivity in rhesus monkeys was shown to consist exclusively of DES. Glucuronidation of DES appears to occur in neonatal and fetal rhesus monkeys.

ISSN:0098-4108    

DOI:10.1080/15287397709529577

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

The effects of TCDD exposure on the developing immune system were investigated in F344 rats. Fetal and neonatal rats were exposed to TCDD through maternal dosing (5 μg/kg) on day 18 of gestation and on days 0, 7, and 14 of postnatal life (group I). Another group of neonatal rats was exposed to TCDD through maternal dosing on days 0, 7, and 14 of postnatal life only (group II). Body weights and thymus/body weight ratios were found to be suppressed up to 145 days of age in group I, but only up to 39 days of age in group II. Parameters of cell‐mediated and humoral immune function were investigated. TCDD suppressed cell‐mediated immune function without affecting humoral immune function. Suppression of T‐cell function was selective in that “helper” cell function was not suppressed.

ISSN:0098-4108    

DOI:10.1080/15287397709529578

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

Data on water treatment and the quality of the finished water supply of the 100 largest U.S. cities (population over 60 million) were combined with data on cancer deaths (age‐adjusted) of the county or counties in which the cities lie, to look for significant correlations with altitude and with quality of water supply. The previously discovered decrease in cancer rates with increasing altitude (for countries around the world) was confirmed for these cities. Correlation coefficients, ‐0.46 for males and — 0.32 for females, were very highly significant (p < 0.001). The rates were then “altitude‐adjusted” for the subsequent analysis.

ISSN:0098-4108    

DOI:10.1080/15287397709529579

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor