摘要:

The separate and combined effects of prenatal protein deficiency (6% casein) and prenatal nitrofen (2,4‐dichlorophenyl‐p‐nitrophenyl ether) exposure (12.5 mg/kg on gestational d 7–21) on renal morphology in the 21‐d fetal and postnatal rat were examined. Body weights and kidney weights were reduced in prenatally protein‐deprived (PPD) pups at birth and on postnatal day (PND) 10. Numbers of mature glomerull, creatinine clearance, water diuresis, and response of antidiuretic hormone (ADH), but not the concentrating ability, were lower in the PPD neonates. These changes suggest that prenatal protein deficiency delays renal development and possibly results in a decrease in glomerular clearance and in tubular response to a water load and to anti‐diuretic hormone.

ISSN:0098-4108    

DOI:10.1080/15287398609530902

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Rats were injected sc with 120 μg/kg Soman, 120 μg/kg Sarin or 240 μg/kg Tabun. At 15 min, 2 h, or 6 h after administration, animals were decapitated along with saline‐treated controls, and striatal activities of nucleotide cyclases and phosphodiesterases and striatal cyclic nucleotide levels were determined. All three agents had two similar effects on rat striatal cyclic nucleotide systems: (1) they all increased cyclic GMP levels 15 min after their administration, and (2) they all decreased guanylate cyclase activity 2 h after administration. There were also some different effects elicited by these three organophosphorus compounds. Different effects of Soman and Sarin seem to be mainly due to their different potencies, which in turn influence the time course of their actions. Tabun is quite different from Soman and Sarin in several respects: (1) it rarely causes convulsions at sub‐lethal doses, (2) it has no effects on striatal cyclic AMP levels, and (3) it affects enzyme activities 6 h after its administration. These differences may be due to the presence of cyanide instead of fluoride in its structure: i.e., this may be responsible for the different effects of Tabun on striatal cyclic nucleotide systems, and perhaps other biochemical effects. These results also indicate that other neurotransmitter systems, in addition to the cholinergic system, may be involved in organophosphate‐induced toxicity.

ISSN:0098-4108    

DOI:10.1080/15287398609530903

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Fischer 344 (SPF) rats were exposed by inhalation to respirable paniculate levels of 2 mg/m3diesel emissions, diesel emissions plus coal dust, coal dust, or air for 7 h/d, 5 d/wk for 24 mo. The effects of treatment on body and heart weights, right and left ventricular wall thickness, severity of cardiomyopathy, and changes in the small pulmonary arteries were evaluated after 24 mo of exposure. In all dust‐exposed animals, light microscopic examination of the lungs revealed dust‐laden macrophages in alveolar spaces and focal accumulations of dust‐laden macrophages near the respiratory bronchioles associated with hyperplasia of type II cells. This response was more prominent in animals exposed to diesel emissions alone. Age‐related myocardial fibrosis and inflammatory infiltrates were common in all four groups. No statistically significant differences were detected between the groups for heart weights, ventricular wall thickness, and pulmonary arterial wall thickness. However, animals exposed to diesel emissions did show a consistent trend toward increased pulmonary arterial wall thickness, for all size categories of artery, compared to controls.

ISSN:0098-4108    

DOI:10.1080/15287398609530904

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

A comparison of the concentration‐response effects of inhaled ozone (O3) and phosgene (COCI2) in different species of laboratory animals was made in order to better understand the influence of the choice of species in inhalation toxicity studies. The effect of 4‐h exposures to ozone at concentrations of 0.2, 0.5, 1.0, and 2.0 ppm, and to COCI2and 0.1, 0.2, 0.5, and 1.0 ppm was determined in rabbits, guinea pigs, rats, hamsters, and mice. Lavage fluid protein (LFP) accumulation 18–20 h after exposure was used as the indicator of O3‐ and COCI2‐induced pulmonary edema. All species had similar basal levels of LFP (250–350 mg/ml) when a volume of saline that approximated the total lung capacity was used to lavage the collapsed lungs. Ozone effects were most marked in guinea pigs, which showed significant effects at 0.2 ppm and above. Mice, hamsters, and rats showed effects at 1.0 ppm O3and above, while rabbits responded only at 2.0 ppm O3. Phosgene similarly affected mice, hamsters, and rats at 0.2 ppm and above, while guinea pigs and rabbits were affected at 0.5 ppm and above. Percent recovery of lavage fluid varied significantly between species, guinea pigs having lower recovery than other species with both gases. Lavage fluid recovery was lower following exposure to higher levels of O3but not COCI2. Results of this study indicate that significant species differences are seen in the response to low levels of O3and COCI2. These differences do not appear to be related in a simple manner to body weight.

ISSN:0098-4108    

DOI:10.1080/15287398609530905

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Nitropolycyclic aromatic hydrocarbons (nitroarenes), including 6‐nitrobenzo[a]pyrene (6‐NBap), occur in our environment and are mutagenic in bacterial mutagenesis assays. The mutagenicity of 6‐NBaP is enhanced when rat liver S9 is added. To investigate the cause of this increased activity, the metabolism of 6‐NBaP was carried out with a total rat liver homogenate obtained from 3‐methylcholanthrene‐ (MC‐) induced rats, a 9000 × g supernatant enzyme, and with both unwashed and washed microsomes. Ring‐hydroxy‐lated 6‐NBaP was detected. On the basis of retention times for known standards in a high‐performance liquid chromatographic system, benzo[a]pyrene (BaP) and 6‐acetoxy‐BaP (6‐OAcBaP) were isolated as products. BaP was further characterized via ultraviolet (UV) and mass spectra and 6‐OAcBaP by UV, mass, and nuclear magnetic resonance (NMR) spectra. 6‐HydroxyBaP (6‐OHBaP) was also detected by UV and mass spectra. It is suggested that BaP is formed via a nitroanion radical of 6‐NBaP and undergoes metabolism, while the 6‐OHBaP is acetylated to form 6‐OAcBaP. The acetyl donor remains to be identified.

ISSN:0098-4108    

DOI:10.1080/15287398609530906

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Four‐week‐old male chickens were subjected to one of the following treatments: 0 ppm mercury (Hg) plus water ad libitum, 0 ppm Hg plus limited water (LW), 500 ppm Hg plus water ad libitum, and 500 ppm Hg plus LW. Exposure was for each of the following time intervals: 0–3, 0–6, 0–9, 0–12, and 0–15 d. LW significantly increased red blood cell (RBC) numbers, hematocrit (HCT), mean corpuscular volume (MCV), and hemoglobin (Hb) level and significantly decreased mean corpuscular hemoglobin (MCH) level within 3 d of treatment. Mercury produced variable results, with no sig‐nificnat trends developing during the treatment period. The effects caused by Hg apperared to be masked by the effects of dehydration. The birds receiving water ad libitum had numerically greater RBC numbers and HCT and Hb levels than birds receiving water ad libitum that was contaminated with Hg, while the effects caused by Hg in the groups that received limited water were not consistent. Each group was given a recovery period of 14 d, during which time all birds received uncontaminated water and feed ad libitum. The hematologic effects caused by Hg and water deprivation did not return to a normal condition. Reduced RBC numbers, HCT, and Hb levels were observed at the end of the recovery period in the birds that were exposed to Hg and/or water deprivation.

ISSN:0098-4108    

DOI:10.1080/15287398609530907

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

To investigate the mechanism by which zinc suppresses mercury toxicity, the effects of zinc and mercury on giutathione (GSH) metabolism in the rat kidney were studied. When the time course of GSH level in the rat kidney was examined at 2, 6, and 12 h after treatment of rats with both metals, an increase of GSH was found and was apparently related to the activation of some GSH‐associated enzymes. In the kidney of rats treated with both metals, the response of the protective function involving GSH and GSH‐associated enzymes depended on the magnitude of mercury toxicity but appeared to be independent of the zinc dosage. The administration of diethyl maleate (DEM), which depletes GSH, increased lipid peroxidation and mercury toxicity concomitantly with a decrease of GSH level in the kidney of rats treated with zinc and mercury. In conclusion, the data suggest that an increased GSH level in the kidney resulting from the activation of GSH‐associated enzymes plays a role in the protective effect of zinc against mercury toxicity.

ISSN:0098-4108    

DOI:10.1080/15287398609530908

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Woodchucks (Marmota monax) were fed crown vetch (Coronilla varia) growing along a major highway that was harvested in 1979, before unleaded gas was widely used, and again in 1985. Crown vetch, harvested 300 m from the nearest road, was fed as the control. The crops were fed as 50% dry weight of the diet for 58 d. The concentrations of lead in the control, 1979 crop, and 1985 crop were, respectively, 0.74, 50.65, and 6. 78 ppm dry weight. The average ± SE) concentrations (ppm, dry weight) of lead found in the tissues of the control, 1979, and 1985 dietary‐treatment animals were, respectively, kidney, 0.36 ± 0.05, 5.78 ± 0.72, and 0.79 ± 0.09; liver, 0.09 ± 0.01, 4.71 ± 0.17, and 0.46 ± 0.06; muscle, 0.07 ± 0.01, 0.14 ± 0.02, and 0.07 ± 0.00; blood, 0.09 ± 0.02, 2.17 ± 0.13, and 0.31 ± 0.05; and bone, 1.27 ± 0.25, 47.52 ± 7.05, and 3.71 ± 0.65. No significant differences (p > 0.05) between dietary treatments were found in the general hematological analyses of the woodchucks. The ecological significance of these findings is discussed.

ISSN:0098-4108    

DOI:10.1080/15287398609530909

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The purpose of our investigation was to determine blood and tissue levels of aluminum (Al) in normal young rabbits. Furthermore, we wished to determine tissue distribution and accumulation of Al as related to its blood concentration in Al‐dosed rabbits. The levels of Al accumulated were determined in different tissues of growing rabbits after continuous subcutaneous administration of Al chloride (3.78 mg/d) for 28 d. No signs of toxicity were apparent from comparisons of hematocrit or weight gain between control and Al‐dosed rabbits. The largest concentration of the AI was observed in bone, which was also found to have the highest levels in the control rabbit tissues. Following bone, the experimental animals showed the greatest increase of Al levels in kidney cortex, kidney medulla, liver, testes, skeletal muscle, heart, brain white matter, and brain hippocampus, in that order. No significant difference was found in brain grey matter between control and experimental animals. As the brain tissue of the Al‐treated animals had the lowest Al level of the tissues measured, it appears that there is a partial blood‐brain barrier to entry of Al.

ISSN:0098-4108    

DOI:10.1080/15287398609530910

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Nickel subsulfide (Ni3S2), nickel sulfate (NiSO4), nickel chloride (NiCl2), and nickel oxide (NiO), are four compounds encountered by workers in the nickel‐refining and electroplating industries. These compounds were tested for their relative toxicity to beagle dog and F344/Crl rat alveolar macrophages in vitro. Dog alveolar macrophages were at least 10 times more sensitive to the effects of each of the 4 nickel compounds than were rat alveolar macrophages. Toxicity ranking of the four nickel compounds to macrophages from both species was Ni3S2> NiCl2∼ NiSO4> NiO.

ISSN:0098-4108    

DOI:10.1080/15287398609530911

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor