共查询到20条相似文献，搜索用时 31 毫秒
1.
A pentachlorophenol (PCP) wood treatment plant was studied to determine PCP exposure to people by occupation and to the plant by work area. This plant operates on a year-round basis with a 25 percent increase in production from May through October. Approximately 2.5 million board feet of timber are processed annually. Samples were taken in the morning of the second work week of each month for 5 consecutive months. Samples consisted of serum and urine from the employees and air from locations throughout the plant work area. All samples were analyzed for PCP residue. Peripheral blood was used to culture cells to investigate possible chromosomal aberrations. 相似文献
2.
3.
The effect of a single low dose of parathion on renal water and electrolyte excretion was studied in anesthetized mongrel dogs. Sodium excretion significantly increased 20 min after iv administration of 1.5 μg parathion/kg body wt, while urine output slightly increased and potassium excretion significantly decreased. No change was observed in glomerular filtration rate, renal plasma flow, filtration fraction, and plasma sodium concentration. Respiratory frequency, heart rate, and arterial blood pressure remained unchanged throughout the experiments. With the doses used, no inhibition of acetylcholinesterase in red blood cells or renal tissues was found. The administration of a single dose of 1 μg atropine sulfate/kg body wt iv had no effect in all the parameters measured but was able to completely block the natriuretic effect of parathion when given ten minutes prior to parathion. Since the dose used showed no inhibitory effect on acetylcholinesterase, it is unlikely that the natriuretic effect of parathion could be due to changes in enzyme activity but rather to conformational changes in tubular membranes altering sodium reabsorption. 相似文献
4.
Nobuyoshi Mikami Jun Yoshimura Hideo Kaneko Hirohiko Yamada Junshi Miyamoto 《Pest management science》1985,16(1):33-45
Upon single oral administration to rats, the mono-, di- and tri-glucose conjugates of [14C]-3-phenoxybenzyl alcohol ( I ) or the mono-glucose conjugate of [14C]-3-phenoxybenzoic acid ( II ) were rapidly hydrolysed and extensively eliminated in the urine mostly as the sulphate conjugate of 3-(4-hydroxyphenoxy)benzoic acid ( X ). The faecal elimination was a minor route, whereas the biliary excretion was about 42% of the dose and the glucuronide conjugates of I , II and X were common major metabolites. The biliary glucuronides were cleaved in the small intestine to the respective aglycones, which were reabsorbed, metabolised further, and excreted in the urine as the sulphate conjugate of X . Although small amounts of the mono-, di-and tri-glucosides were found in the 0.5-h blood and liver samples following oral administration of the tri-glucoside of I , they were not detected in the urine, bile or faeces. Similarly the sulphate conjugate was one of the major urinary metabolites of germ-free rats, dosed with the 14C-glucosides via the oral or the intraperitoneal route, although they were excreted unchanged in certain amounts in the urine and faeces. The glucose conjugates were cleaved in vitro by gut microflora and in various rat tissues, including blood, liver, small intestine and small intestinal mucosa. The tissue enzymes showed a different substrate specificity in hydrolysis of the glucosides. However, they were not cleaved in gastric juice, bile, pancreatic juice or urine. 相似文献
5.
为阐明杀虫剂哌虫啶在SD大鼠体内的代谢动力学过程,以期为进一步的毒理学研究提供依据,采用所建立的高效液相色谱-串联质谱(HPLC-MS/MS)分析方法,测定了单次灌胃给药后大鼠血浆、组织(心、肝、脾、肺、肾、脑、骨骼肌、脂肪)、粪便和尿液样品中哌虫啶的含量,对该药在大鼠体内的吸收、分布和排泄进行了研究。结果表明:哌虫啶750 mg/kg单次经口灌胃给药,雌性大鼠血药浓度-时间曲线下面积(AUC)高于雄性大鼠,且达到峰值时间(T_(max))明显长于雄性大鼠,具有统计学差异,提示在此剂量下,哌虫啶在代谢及毒性效应上可能存在性别差异;在100~750 mg/kg受试剂量范围内,哌虫啶的平均半衰期为4~8 h,表观分布容积为10~30 L/kg,给药剂量与血药浓度-时间曲线下总面积(AUC_(0-inf))呈线性相关性(雄:r=0.996 4,雌:r=0.991 3)。组织分布试验表明,哌虫啶经口给药后,能迅速、广泛地分布到各组织中,并可有效地透过血脑屏障,其中肝、肾中哌虫啶的含量最高,提示其可能主要经肝、肾代谢。排泄试验显示,经尿液及粪便排出的原形哌虫啶含量极低,提示哌虫啶在大鼠体内可能发生广泛的代谢后再排出体外。 相似文献
6.
采用单次灌胃染毒法,通过高效液相色谱仪测定,研究了苯肽胺酸(N-phenylphthalamicacid,PPA)在大鼠体内的吸收、组织分布及排泄情况,以及其血药浓度经时变化过程和毒物动力学参数。结果表明:苯肽胺酸经消化道吸收速率较快,其半吸收期t1/2ka仅为(0.15±0.11) h,血药浓度的达峰时间(tmax)为(0.68±0.37) h,血药峰浓度(Cmax)值为(141.48±27.87) mg/L;苯肽胺酸在大鼠体内分布快且分布范围广,半分布期(t1/2α)为(0.22±0.18) h,表观分布容积(Vz/F)为(17.54±7.71) L/kg;苯肽胺酸从大鼠体内消除较快,其清除率(CLz/F)为(1.32±0.51) (L/h)/kg,在体内平均驻留时间(MRT(0-∞))为(25.69±2.93) h,消除半减期(t1/2z)为(7.77±1.44) h,约35 h后95%以上的苯肽胺酸可从大鼠体内消除。研究发现:苯肽胺酸的浓度-时间曲线呈现双峰现象,提示其在大鼠体内可能存在肠-肝循环。从大鼠灌胃染毒后至24 h内,被测各组织、脏器中均可检出苯肽胺酸,其浓度由高到低依次为:肾脏> 肺> 肝脏> 心脏> 脾脏> 肌肉> 睾丸> 脂肪> 大脑,肾脏中药物含量达192.7 μg/g,同时仅肾脏组织的靶向分布系数(te)值大于1(4.77),提示苯肽胺酸在大鼠体内分布时对肾脏具有相对较高的选择性。排泄物研究结果显示,苯肽胺酸随粪便排出的总量仅占给药量的1.45%,而尿液中未检出苯肽胺酸。 相似文献
7.
Two wild oat herbicides, benzoylprop-ethyl and flamprop-methyl were administered to lactating cows at low dose levels (0.3–3.0 mg/kg in total diet) and the excretion of total metabolites in milk, urine and faeces was measured. Total residues in tissues were also determined. Similarly a third and related herbicide flamprop-isopropyl was fed to cows, pigs and hens (at 0.5 mg/kg in total diet) and the residues were determined in excreta and tissues, including eggs. The amounts of the compounds fed were equivalent to approximately 10–300 times the total residue found in cereal treated in the field. Residues in milk in most cases were well below 0.001 mg/kg; in muscle samples <0.003 mg/kg; and in eggs, 0.0008 mg/kg, decreasing by 50% in approximately 3 days to 0.0001 mg/kg 4 days after the termination of treatment. Elimination of the herbicides from the animals was rapid in every case and this, together with the low residue levels, was attributed to very efficient metabolic de-esterification to the parent carboxylic acid metabolites (benzoylprop and flamprop). These metabolites possess physical properties ideally suited for excretion via the kidneys and bile into urine and faeces and, conversely, unsuited for transport into milk and eggs. 相似文献
8.
利用大蜡螟Galleria mellonella L.诱集法,从采自吉林省的土样中分离到小杆类昆虫病原线虫1种。经形态学、ITS及28S rDNA序列分析鉴定,明确了该线虫为Oscheius tipulae JL1。室内生物测定结果表明:24 h时,线虫JL1浓度为120 IJs/larva及以上时,大蜡螟的死亡率达90%以上;48 h时,浓度40 IJs/larva时,大蜡螟死亡率达93%以上;60 h时,浓度高于20 IJs/larva时,大蜡螟死亡率100%。耐热性方面,在38℃下处理8 h,线虫死亡率快速增加,35℃处理16 h,线虫死亡率开始快速增加。线虫JL1在35和38℃条件下,分别至少可耐16和8h的高温,死亡率分别在3.2%和15.3%以下。结果表明该线虫具有较好的耐热力、侵染力和致死力,未来有望用于害虫防治。 相似文献
9.
Rudolf Schmitt Jürgen Kaul Theo v.d. Trenck Egmont Schaller Heinrich Sandermann 《Pesticide biochemistry and physiology》1985,24(1):77-85
The polar metabolite fraction formed by soybean cell suspension cultures from [14C]pentachlorophenol (PCP) was fractionated by repeated high-performance liquid chromatography. The β-d-glucopyranosyl conjugate of PCP was identified by cochromatography, by chemical and enzymatic degradation, and by mass spectroscopic comparison with the authentic compound. The O-(malonyl)-β-d-glucopyranosyl conjugate of PCP was identified by chromatographic and electrophoretic comparison with the enzymatically synthesized compound, by specific chemical and enzymatic degradation, and by mass spectroscopy. Soluble protein extracts from both soybean and wheat cells catalyzed (a) the UDPG-dependent conversion of PCP to the β-d-glucopyranosyl conjugate, and (b) the malonyl-SCoA-dependent further conversion to the O-(malonyl)-β-d-glucopyranosyl conjugate. These enzymes were partially purified and had apparent molecular weights between 40,000 and 48,000. Free PCP was again released from the conjugates upon incubation with plant malonyl esterase and/or β-glucosidase preparations. 相似文献
10.
《Pesticide biochemistry and physiology》1986,25(1):31-39
Three experiments were conducted that examined the effects of three different pentachlorophenol (PCP) preparations on microsomal mixed-function oxidases (MFO) when administered subchronically to cattle. Induction of mixed function oxidases was exclusively of the 3-methylcholanthrene (MC) type with benzo(a)pyrene hydroxylase (or arylhydrocarbon hydroxylase) being the most inducible enzyme. This effect was observed in both calves and adult cattle, in both hepatic and pulmonary microsomes, and was dose related. Although a greater response was indicated in cattle fed technical PCP, significant benzo(a)pyrene hydroxylase induction was measured in calves fed analytical PCP. This effect was not observed in adult cattle. None of the preparations stimulated phenobarbital (PB) type MFO. Liver enlargement was minimal and was restricted to cattle fed technical PCP. 相似文献
11.
西安南郊不同深度土壤CO_2浓度变化研究 总被引：2，自引：0，他引：2
利用红外CO2监测仪对西安南郊不同深度条件下的土壤CO2浓度进行了多次昼夜观测。观测结果表明:在一昼夜内土壤CO2浓度具有从低到高再到低的变化规律,这种变化特点与昼夜温度变化基本一致;土壤CO2浓度从总体来看具有白天高,夜间低,夏季高,秋季低的特点;浅层土壤CO2浓度昼夜变化幅度明显大于深层土壤CO2浓度变化幅度;在厚层黄土的150cm深度范围内,土壤CO2浓度随着深度的增加而增加,在150~600cm深度范围内CO2浓度基本恒定,显示出与薄层土CO2浓度变化明显不同。 相似文献
12.
Oxygen consumption and ammonia excretion of the freshwater crab Trichodactylus borellianus exposed to chlorpyrifos and endosulfan insecticides 总被引：1，自引：0，他引：1
The effects of lethal and sublethal concentrations of chlorpyrifos and endosulfan on oxygen consumption and ammonia excretion rate of the crab Trichodactylus borellianus were evaluated. Oxygen consumption and energy expenditure had significant effect in relation to exposure times. Regarding endosulfan, a significant difference in consumption among times of exposure was registered in 625 μg L−1. Moreover, at the highest concentration, energy expenditure rate was observed stabilized during 1-3 h. A significant increase in ammonia excretion was evidenced in 150 and 300 μg L−1 of chlorpyrifos. The O:N ratio showed a decrease in chlorpyrifos and in 2500 μg L−1 of endosulfan. This indicated a shift towards protein primary metabolism. An increment in the O:N ratio was observed in the lower endosulfan solutions. The relation oxygen:nitrogen showed a shift towards lipid and carbohydrate primary metabolism. This work indicated the complexity of the metabolism in the freshwater crab affected by xenobiotic elements. 相似文献
13.
为掌握海南省芒果中农药的多残留情况及其对慢性膳食摄入风险的贡献大小,采集海南省主产区芒果样品178份,分别采用气相色谱及超高效液相色谱-串联质谱方法测定了样品中农药的残留情况,并计算了芒果中所检出农药对我国不同人群慢性膳食摄入风险的贡献份额 (R)。结果表明:甲氧基丙烯酸酯类和新烟碱类农药的残留检出率最高 (> 80.00%)。根据我国制定的相关最大残留限量 (MRL) 标准,以下农药残留量均存在超标现象,其中吡唑醚菌酯共有39份样品超标,吡虫啉34份,噻虫胺5份,苯醚甲环唑2份,灭多威和多效唑各1份;71.91%的样品同时含有2种及2种以上单个农药残留,最多者同时检出了8种单个农药残留;同时检出2种及2种以上甲氧基丙烯酸酯类或新烟碱类农药的样品比例分别为23.03%和16.30%;嘧菌酯/吡唑醚菌酯、吡虫啉/吡唑醚菌酯、吡虫啉/嘧菌酯是最常见的农药多残留组合。本研究所检出农药的R值均远远低于1,说明通过芒果摄入的农药残留对整个慢性膳食摄入风险的贡献极小。 相似文献
14.
在旱秧田、水秧田、旱直播田和水直播田的试验中,播前施用五氯酚钠,每公顷5—20公斤,除草效果不够良好。但在插秧本田的试验中,插前每公顷施用五氯酚钠15—30公厅对防除稗草(Echinochloa crusgalli (L.) Beauv.)和球穗莎草(Cyperus globosus All.)的效果极为良好。以在插秧前一天,每公顷施用30公斤效果最好,对稗草和球穗莎草的防除效果分别达到92.7%和79.6%。插后处理,每公顷施用五氯酚钠15公斤,效果也较好。另外的试验,观察了五氯酚钠不同剂型:颗粒剂、混土、溶液等的防除效果。防除稗草用颗粒剂和混土处理要优于溶液处理;防除球穗莎草则以溶液处理为最好。各处理对水稻均无药害,所有用五氧酚钠处理区的产量均高于不除草区,但较两次人工除草的为低。本文讨论了在秧田和直播田用五氯酚钠防除稗草效果较差的原因。 相似文献
15.
The metabolism of the carbamate insecticide bendiocarb (2,2-dimethylbenzo-1, 3-dioxol-4-yl methylcarbamate) has been investigated in male and female rats and in a male human volunteer using radiolabelled material. The compound was rapidly and extensively absorbed and completely metabolised following oral administration. In man, absorption was complete, >99% of the dose being excreted in the urine within 22 h. In the rat, > 86% of the radiolabel was excreted in the urine within the first 24 h. Faecal excretion from the rat was minor (3–8% of dose) and a small amount of the compound (1–3%) was metabolised and excreted as [14C]carbon dioxide. The major metabolic pathway in both species involved cleavage of the carbamate ester group to yield the phenol,2,2-dimethylbenzo-1, 3-dioxol-4-ol (I). This metabolite, occurring as sulphate and glucuronide conjugates, accounted for more than 95% of the dose excreted by the human volunteer. In man, small amounts of conjugates of 2, 2-dimethylbenzo-1, 3-dioxol-4-yl N-(hydroxymethyl)carbamate (II) were also found in early samples. In the rat, the metabolism was more complex with the formation of small amounts of conjugates of II and several minor metabolites, thought to be ring-hydroxylated derivatives of bendiocarb and I. 相似文献
16.
《Pesticide biochemistry and physiology》2009,93(3):150-155
The effects of lethal and sublethal concentrations of chlorpyrifos and endosulfan on oxygen consumption and ammonia excretion rate of the crab Trichodactylus borellianus were evaluated. Oxygen consumption and energy expenditure had significant effect in relation to exposure times. Regarding endosulfan, a significant difference in consumption among times of exposure was registered in 625 μg L−1. Moreover, at the highest concentration, energy expenditure rate was observed stabilized during 1–3 h. A significant increase in ammonia excretion was evidenced in 150 and 300 μg L−1 of chlorpyrifos. The O:N ratio showed a decrease in chlorpyrifos and in 2500 μg L−1 of endosulfan. This indicated a shift towards protein primary metabolism. An increment in the O:N ratio was observed in the lower endosulfan solutions. The relation oxygen:nitrogen showed a shift towards lipid and carbohydrate primary metabolism. This work indicated the complexity of the metabolism in the freshwater crab affected by xenobiotic elements. 相似文献
17.
A competitive enzyme-linked immunosorbent assay (ELISA) for fenoxycarb was adapted for quantitative detection of this insect growth regulator in various environmental, agricultural, food and biological matrices. Environmental samples were taken from soil and surface waters in Hungary. The ELISA enabled fenoxycarb detection in surface waters in the 1.1-125 ng ml(-1) concentration range without sample cleanup. In contrast, soil produced a strong matrix effect due to humic acids and other soil components. Several fruit homogenates and commercial fruit juices (eg apple, pear, grape) were analyzed by the ELISA. The assay was found to be suitable for analysis of fenoxycarb in fruit juices diluted 1:40. Biological samples included insect, fish and bovine tissues. The ELISA was applied to detect fenoxycarb in various biological matrices from larvae of the silkworm, Bombyx mori L. The assay proved useful for the analysis of haemolymph diluted 1:10 or at higher dilutions. Fat body and whole body homogenates, however, caused severe matrix effects. Fenoxycarb was detected in liver homogenates (diluted 1:40) from fish treated with various doses of fenoxycarb, and the concentrations determined correlated with the applied doses. The method was used to analyze spiked bovine urine samples diluted 1:10 or at greater dilutions. Fenoxycarb content determined by the ELISA in water and fruit juice samples was validated using GC-MS with solid-phase microextraction (SPME) sample preparation. The results of these studies demonstrated both the value and limitations of the assay when used for monitoring fenoxycarb in environmental, food and biological samples. 相似文献
18.
19.
The toxicity of diazinon and diazoxon to fourth instar Pieris brassicae larvae was determined, with or without modifying chemicals. Piperonyl butoxide and sesamex antagonised diazinon but synergised diazoxon. The penetration, excretion and internal concentration of diazinon were measured following topical application. Penetration of diazinon followed first order kinetics and was considerably slower after pretreatment with sesamex and piperonyl butoxide. Pretreatment with piperonyl butoxide increased the internal concentration of diazinon, but the onset of symptoms of poisoning was delayed, presumably because of inhibition of diazinon activation. 相似文献
20.
为评估福建省主产区普通白菜中农药残留水平及对人体的膳食暴露风险,采用现有的标准检测方法,对在福建省主产区采集的88个普通白菜样品中的68种农药残留进行了检测分析,并对检出农药进行了短期和长期膳食暴露风险评估。结果显示：88个普通白菜样品中,共有68个样品检出了农药残留,总检出率为77.27%;共检出27种农药,其中杀虫剂18种,杀菌剂9种;检出2种及2种以上农药残留的样品占检出农药残留样品总量的83.82%,存在农药多残留现象。利用相关农药的毒理学数据——急性参考剂量(ARfD)和每日允许摄入量(ADI)、农药残留数据和普通白菜的膳食消费量数据,评估了所检出农药的短期和长期膳食暴露风险。其中,短期膳食暴露风险值(%ARfD)范围为0～90%,长期膳食暴露风险商贡献率(RQc%)范围为0～46%。研究表明,福建省主产区普通白菜中的农药残留水平较低,通过食用该地区生产的普通白菜对消费者的农药残留膳食暴露风险整体在可接受范围内。 相似文献