Preliminary observations on the effects on the organs of mice of administering some carbamate pesticides

Summary Two pesticides, Karbatox 75 and Unden, were used for the investigation, in daily doses of 20 mg per kg body weight, injected intraperitoneally during a period of 20 days. A comparatively low toxicity of these compounds for mice was ascertained. Among morphological changes were found: hypertrophy of the intestinal epithelium, a decrease in size of liver cells and a significant increase in number of Gomori-positive glia cells, as well as an increase in the volume of cell nuclei in the neurosecretory neurocytes of hypothalamus.The authors regard the present paper as an introduction to a more complete cycle of investigations devoted to the problem of pesticide effects.     

丙烯酰胺对人角质形成细胞DNA损伤的研究

目的　研究丙烯酰胺 (AA)对人角质形成细胞的细胞毒性和对DNA的损伤及其可能机制。方法　 (1 )人角质形成细胞株HaCaT细胞经AA浓度梯度染毒 44h后 ,以四氮唑盐 (MTT)法检测细胞存活率。 (2 )细胞经AA浓度梯度染毒 ,以彗星试验检测细胞DNA损伤。 (3)细胞经 2 .0 0mmol/LAA和 0 .50mmol/L的细胞色素P 450 (CYP 450 )抑制剂 1 ABT共处理 4h后 ,以彗星试验探索DNA损伤与CYP 450的关系。结果　 (1 )细胞毒性试验显示 ,AA染毒 44h后细胞存活率显著下降。 (2 )AA染毒 4h未观察到细胞毒性 ,但各组细胞的DNA较对照组均检测到显著损伤 ,且损伤程度随染毒剂量增大而加重 ,彗尾长度在处理剂量范围内有明显的剂量效应关系 ;细胞经 1 ABT和 2 .0 0mmol/LAA共同处理后 ,拖尾率和尾长为 1 5 .4 %和 (8.2± 2 .0 ) μm ,较 2 .0 0mmol/LAA组 [80 .6 %和 (44.3± 4 .0 ) μm]明显降低 ,差异有显著性 (P <0 .0 1 )。结论　AA对HaCaT细胞具有细胞毒性和基因毒性 ,AA诱导的DNA损伤可能与其经CYP 450作用产生的氧化代谢物有关     

Lung function and respiratory symptoms in male Palestinian farmers

In a cross-sectional study of 250 farmers aged 22 to 77 years, of whom 36.4% are smokers, the authors aimed at describing lung function and respiratory symptoms and to estimate associations with exposures to pesticides and dust. Lung function was measured using a spirometer. Respiratory symptoms and exposure levels were self-reported based on a modified standardized questionnaire. Mean forced vital capacity (FVC) was 4.20 L (SD = 0.93 L), 95.51% of predicted as compared to European standards. Mean forced expiratory volume in one second (FEV(1)) was 3.28 L (SD = 0.80 L), 91.05% of predicted. The authors found high symptom prevalences: 14.0% for chronic cough; 26.4% for wheeze; and 55.2% for breathlessness. There was no clear association between exposure to pesticides or dust and lung function or between such exposures and respiratory symptoms. However, a significant association was found between smoking and respiratory symptoms such as chronic cough, cough with phlegm, and wheezes. The lack of farm exposure associations could be due to improvement in farmers' awareness to pesticides hazards as well as regulations of pesticide import, or because of inherent problems with the experimental design. Farmers who kept animals and poultry seem to have less respiratory symptoms and better lung function.     

Anti-stress effects of ginseng via down-regulation of tyrosine hydroxylase (TH) and dopamine ��-hydroxylase (DBH) gene expression in immobilization-stressed rats and PC12 cells

Catecholamines are among the first molecules that displayed a kind of response to prolonged or repeated stress. It is well established that long-term stress leads to the induction of catecholamine biosynthetic enzymes such as tyrosine hydroxylase (TH) and dopamine β-hydroxylase (DBH) in adrenal medulla. The aim of the present study was to evaluate the effects of ginseng on TH and DBH mRNA expression. Repeated (2 h daily, 14 days) immobilization stress resulted in a significant increase of TH and DBH mRNA levels in rat adrenal medulla. However, ginseng treatment reversed the stress-induced increase of TH and DBH mRNA expression in the immobilization-stressed rats. Nicotine as a ligand of the nicotinic acetylcholine receptor (nAChR) in adrenal medulla stimulates catecholamine secretion and activates TH and DBH gene expression. Nicotine treatment increased mRNA levels of TH and DBH by 3.3- and 3.1-fold in PC12 cells. The ginseng total saponin exhibited a significant reversal in the nicotine-induced increase of TH and DBH mRNA expression, decreasing the mRNA levels of TH and DBH by 57.2% and 48.9%, respectively in PC12 cells. In conclusion, immobilization stress induced catecholamine biosynthetic enzymes gene expression, while ginseng appeared to restore homeostasis via suppression of TH and DBH gene expression. In part, the regulatory activity in the TH and DBH gene expression of ginseng may account for the anti-stress action produced by ginseng.     

The phytoestrogen daidzein affects the antioxidant enzyme system of rat hepatoma H4IIE cells

Phytoestrogens such as the soy isoflavonoid daidzein have potential health benefits. The antioxidant properties of phytoestrogens are considered to be responsible in part for their protective effects. The antioxidant enzyme (AOE) system plays an important role in the defense of cells against oxidative insults. To determine whether flavonoids can exert antioxidative effects not only directly but also indirectly by modulating the AOE system, we investigated the influence of the flavonoid daidzein on the expression of different AOE. Daidzein treatment of hepatoma H4IIE cells increased catalase mRNA expression two- to threefold. Expression levels of copper zinc superoxide dismutase (CuZnSOD) were not affected by exposure to daidzein. Manganese superoxide dismutase (MnSOD) mRNA expression levels decreased slightly and glutathione peroxidase (GPx) levels increased slightly after daidzein exposure. Changes in AOE mRNA expression levels were significant at 300 micromol/L daidzein. To elucidate the mechanisms underlying the strong increase in catalase mRNA, transfection experiments were performed. Transient transfection of hepatoma cells with reporter plasmids containing different parts of the upstream region of the catalase gene showed a significant one- to threefold increase in reporter gene activity after daidzein exposure. This indicates that daidzein can directly activate the rat catalase promoter region. Despite the increase in catalase mRNA, daidzein pretreatment of cells did not protect against oxidative stress resulting from H(2)O(2) exposure. On the contrary, daidzein itself exerted a mild oxidative stress. In conclusion, the changes in the AOE system provoked by daidzein affected the oxidant rather than the antioxidant properties of daidzein.     

Combined use of biomarkers and in situ bioassays in Daphnia magna to monitor environmental hazards of pesticides in the field

The aim of this investigation was to evaluate toxicity effects of pesticides in aquatic invertebrates using in situ bioassays with the local species, Daphnia magna. Investigations were carried out in the Delta del Ebro (northeast Spain) during the main growing season of rice (May-August). Measures of energy consumption (i.e., algal grazing) and of specific biochemical responses (biomarkers) were conducted in individuals transplanted at four stations, including a clean site upstream of the affected area and the three main channels that collect and drain the water from the rice fields into the sea. Seventeen pesticides were analyzed in water by on-line solid-phase extraction-liquid chromatography-tandem mass spectrometry. The results obtained indicated high levels of pesticides in water, with peak values of 487 microg/L for bentazone, 8 microg/L for methyl-4-chlorophenoxyacetic acid, 5 microg/L for propanil, 0.8 microg/L for molinate, and 0.7 microg/L for fenitrothion. Measured biological responses denoted severe effects on grazing rates; a strong inhibition of cholinesterases and carboxylesterases, which are specific biomarkers of organophosphorous and carbamate pesticides; and altered patterns of the antioxidant enzyme catalase and the phase II metabolizing enzyme glutathione S-transferase. Correlation analysis with pesticide residue levels converted to toxic units relative to its acute 48-h median lethal concentration of D. magna indicated significant and negative coefficients between the dominant pesticide residues and the observed biological response, thus denoting a clear cause-and-effect relationship. The results emphasize the importance of considering specific (biomarkers) as well as more generalized and ecologically related (grazing) in situ responses to identify and evaluate biological effects of environmental contaminants in the field.     

Lung Function and Respiratory Symptoms in Male Palestinian Farmers

ABSTRACT

In a cross-sectional study of 250 farmers aged 22 to 77 years, of whom 36.4% are smokers, the authors aimed at describing lung function and respiratory symptoms and to estimate associations with exposures to pesticides and dust. Lung function was measured using a spirometer. Respiratory symptoms and exposure levels were self-reported based on a modified standardized questionnaire. Mean forced vital capacity (FVC) was 4.20 L (SD = 0.93 L), 95.51% of predicted as compared to European standards. Mean forced expiratory volume in one second (FEV₁) was 3.28 L (SD = 0.80 L), 91.05% of predicted. The authors found high symptom prevalences: 14.0% for chronic cough; 26.4% for wheeze; and 55.2% for breathlessness. There was no clear association between exposure to pesticides or dust and lung function or between such exposures and respiratory symptoms. However, a significant association was found between smoking and respiratory symptoms such as chronic cough, cough with phlegm, and wheezes. The lack of farm exposure associations could be due to improvement in farmers’ awareness to pesticides hazards as well as regulations of pesticide import, or because of inherent problems with the experimental design. Farmers who kept animals and poultry seem to have less respiratory symptoms and better lung function.     

In vivo Hepato-protective Properties of Purslane Extracts on Paracetamol-Induced Liver Damage

This investigation is designed to evaluate the potential hepato-protective effect of ethanolic and aqueous extracts of air-dried leaves of Purslane against paracetamol-induced hepato-toxicity, in an attempt to understand its mechanism of action, which may pave the way for possible therapeutic application. Paracetamol (1g/kg bw) administration to rats resulted in massive elevation in serum and hepatic lactate dehydrogenase (LDH) activity and thiobarbituric acid reactive substances (TBARS) as well as in serum tumor necrosis factor-alph (TNF-α) levels, with a significant decrease in serum and hepatic protein thiols (Pr-SHs) and reduced glutathione (GSH) superoxide dismutase (SOD) and glutathione peroxidase (GPx) in blood and liver. Oral administration of both the leaves extracts at a concentration of 150 mg/kg bw daily for 15 days showed significant protection against an induced increase in serum and hepatic LDH and TBARS as well as serum tumor necrosis factor-alph (TNF-α) levels. The treatment also resulted in a significant increase in serum and hepatic Pr-SHs as well as GSH, SOD and GPx in blood and liver. The results of the present study suggest that the ethanolic and aqueous extracts of Purslane leaves can generate antioxidants.The effect was more pronounced in ethanolic extract compared to aqueous extract.     

Effects of p-nonylphenol, methoxychlor, and endosulfan on vitellogenin induction and expression in sheepshead minnow (Cyprinodon variegatus)

Temporal and dose-response relationships of vitellogenin (VTG) mRNA induction and subsequent plasma VTG accumulation were established for sheepshead minnows (Cyprinodon variegatus) treated with p-nonylphenol (an alkylphenol) and the organochlorine pesticides methoxychlor and endosulfan. Thirty-two adult male fish per treatment were continuously exposed to measured concentrations of 0.64, 5.4, 11.8, 23.3, and 42.7 micrograms/L p-nonylphenol; 1.1, 2.5, 5.6, 12.1, and 18.4 micrograms/L methoxychlor; and in two separate tests, 15.9, 36.3, 68.8, 162, 277, 403, 590, and 788 ng/L endosulfan using an intermittent flow-through dosing apparatus. Separate triethylene glycol (50 microliters/L) and 17 beta-estradiol (65.1 ng/L) treatments served as the negative and positive controls, respectively. Four fish were randomly sampled from each test concentration on days 2, 5, 13, 21, 35, and 42 of exposure, and levels of hepatic VTG mRNA induction and serum VTG accumulation were determined for each individual. Overall, fish exposed to p-nonylphenol or methoxychlor demonstrated a rapid, dose-dependent synthesis of VTG mRNA up to day 5 of exposure, followed by a relatively constant dose-dependent expression through day 42. Both chemicals showed a dose-dependent increase in plasma VTG over the entire time course of exposure, with significantly elevated VTG levels by the fifth day of exposure to p-nonylphenol at concentrations of 5.4 micrograms/L or greater and to methoxychlor at concentrations of 2.5 micrograms/L or greater. Exposure to 0.64 microgram/L p-nonylphenol resulted in highly variable plasma VTG levels of less than 6 mg/ml. Exposures with endosulfan failed to induce measurable levels of either hepatic VTG mRNA or serum VTG at the chemical concentrations tested. Our results demonstrate that the sheepshead minnow bioassay is a suitable estuarine/marine teleost model for in vivo screening of potentially estrogenic substances.     

The Effects of Copper on Blood and Biochemical Parameters of Rainbow Trout (Oncorhynchus mykiss)

Metals are released into aquatic systems from many sources, often at sublethal concentrations. The effects of sublethal concentrations of metals on fish are not entirely understood. The objective of this study was to determine the hematological and biochemical effects of a range of copper concentrations (6.4, 16.0, 26.9 μg Cu/L) on rainbow trout (Oncorhynchus mykiss) over a prolonged period of time. Trout were exposed to copper, and, at intervals of 3, 7, 14, and 21 days, selected parameters were evaluated. Hemoglobin, hematocrit, plasma glucose, and plasma cortisol levels were elevated in trout exposed to 26.9 μg Cu/L at day 3 and then returned to levels comparable to control fish. Plasma protein and lactate levels were not significantly altered in trout from any copper treatment. Hepatic copper concentration and hepatic metallothionein mRNA expression were consistently elevated in trout exposed to 26.9 μg Cu/L. Both of these parameters stabilized by day 3, with only hepatic copper concentration showing a further increase at day 21. Hepatic copper concentration and hepatic metallothionein mRNA expression appear to be robust indicators of copper exposure. Most blood-based parameters evaluated appear to be associated with a transitory, nonspecific stress response. The return of elevated hematological and biochemical parameters to control levels after 3 days and the stabilization of hepatic metallothionein mRNA expression and copper concentration over a similar time period suggested acclimation to dissolved copper at 26.9 μg/L. Further analysis of the data on blood-based parameters indicated that certain parameters (hemoglobin, hematocrit, plasma glucose, plasma cortisol) may be useful in field monitoring. Received: 12 July 1998/Accepted: 13 December 1998     

扇贝多肽对紫外线A诱导HaCaT细胞Fas、c-fos表达的影响

目的观察扇贝多肽(PCF)对紫外线A(UVA)照射后HaCaT角质形成细胞Fas、c-fos表达的影响,以探讨PCF保护UVA致HaCaT细胞损伤的分子机制。方法体外培养的HaCaT角质形成细胞分为5组:对照组、UVA模型组、5.69mmol/LPCF组、2.84mmol/LPCF组、1.42mmol/LPCF组。蛋白质印迹法检测Fas、c-fos蛋白表达;RT-PCR检测FasmRNA表达;荧光定量PCR检测c-fosmRNA表达。结果 UVA照射后模型组Fas、c-fos表达均显著增加(P0.01),1.42～5.69mmol/L剂量范围内的PCF可抑制UVA引起的HaCaT细胞Fas、c-fosmRNA及蛋白表达(P0.05),且有剂量依赖性。结论 PCF可通过抑制Fas、c-fos表达而抑制UVA诱导的HaCaT细胞损伤。     

邻苯二甲酸二丁酯对大鼠血清雌二醇水平的影响及其机制研究

目的探讨邻苯二甲酸二丁酯(DBP)对青春期雌性大鼠雌二醇(E2)合成的影响及相关机制。方法将32只21日龄SPF级SD雌性大鼠按体重随机分为对照组(玉米油)和低(250mg/kg)、中(500mg/kg)、高剂量(1000mg/kg)DBP染毒组,每组8只。采取灌胃方式进行染毒,染毒剂量为5ml/kg,每天1次,连续灌胃染毒8周。染毒结束后,处死处在动情前期的动物,采用放射免疫法检测血清中E2的水平,实时荧光定量RT-PCR检测大鼠卵巢甾体激素合成过程中关键酶细胞色素P450芳香化酶(cytochrome P450 aromatase,P450arom)mRNA表达水平。结果与对照组比较,中剂量DBP染毒组雌性大鼠体重较高,差异有统计学意义(P0.05)。与对照组相比,各剂量DBP染毒组雌性大鼠血清中E2水平和卵巢P450arom mRNA表达水平均升高,差异有统计学意义(P0.01或P0.05)。结论DBP可使青春期雌性大鼠血清中E2水平升高,其作用机制可能与卵巢甾体激素合成过程中的关键酶P450arom mRNA表达升高有关。     

砷与铅对人及大鼠红细胞脂质过氧化作用的影响

通过体内体外实验探讨了砷与铅对机体脂质过氧化（ＬＰＯ）的联合作用。用离体人红细胞膜染毒，砷（Ａｓ２Ｏ３）在体系中浓度分别是０，０．４，２．０，１０．０及２０．０ｍｍｏｌ／Ｌ；铅（ＰｂＡｃ２）在体系中浓度分别是０，０．０８，０．４及２．０ｍｍｏｌ／Ｌ；联合染毒采用２×２析因设计，各取其剂量的最低无作用剂量，３７℃孵育６０ｍｉｎ测定ＬＰＯ水平。结果显示，砷与铅对离体人红细胞膜ＬＰＯ的影响具有联合作用，其作用形式为相加作用。为观察砷与铅对整体动物的影响，我们采用２×２析因设计，分别取ＬＤ５０的１／５剂量以灌胃的方式染毒，砷为２．４ｍｇ／ｋｇ，铅为３０ｍｇ／ｋｇ，连续１０天。结果显示，砷与铅对大鼠血浆ＬＰＯ作用不明显，但引起红细胞超氧化物歧化酶（ＳＯＤ）活性的明显抑制，红细胞谷胱苷肽（ＧＳＨ）含量下降；析因分析表明，砷与铅对大鼠红细胞ＳＯＤ活性抑制具有联合作用，联合作用形式为相加作用     

砷与铅与人及大鼠红细胞脂质过氧化作用的影响

The authors observed the joint effects of arsenic and lead on lipid peroxidation(LPO) in vitro and in vivo. In vitro, the authors used the extracted erythrocyte membrane of health adult men and divided them into three exposed groups. The first group was exposed to As2O3 (0, 0.4, 2.0 and 10.0 mmol/L). The second group was exposed to PbAc2 (0, 0.08, 0.4 and 2.0 mmol/L). The third group was exposed to As(10 mmol/L) + Pb (0.08 mmol/L). The results show that there is interaction between As and Pb on LPO of erythrocyte membrane. In vivo, the authors measured LPO levels of rat's plasma, blood glutathione(GSH) and superoxide dismutase(SOD) activity. By using 2 x 2 factorial design, Wistar rats were gavaged with As2O3 2.4 mg/(kg.d) and PbAc2 30 mg/(kg.d) as well as both arsenic and lead in water for 10 days. The results show that in the As-Pb treated rats, the levels of LPO did not change significantly, the GSH levels and SOD activity decreased significantly. The results of factorial analysis revealed a synergic effect of As-Pb on SOD activity.     

Dermal in vitro penetration of methiocarb, paclobutrazol, and pirimicarb: effect of nonylphenolethoxylate and protective gloves

Dermal exposure has become the major route of human occupational exposure to pesticides. Detergents are used as part of formulated pesticide products and are known to change the barrier properties of human skin in vitro. However, studies on the influence of detergents as well as protective glove materials on dermal penetration of pesticides are scarce. In an experiment using in vitro static diffusion cells mounted with human skin, we evaluated the effect of nonylphenol-ethoxylate on dermal penetration of three extensively used pesticides--methiocarb, paclobutrazol, and pirimicarb--and the protection against dermal penetration offered by protective gloves made of latex or nitrile. There was a general tendency, though not statistically significant for all pesticides, for nonylphenolethoxylate to decrease the percutaneous penetration of the three pesticides. The nitrile generally offered better protection against percutaneous penetration of pesticides than did latex, but the degree of protection decreased over time and depended on the pesticides used.     

乙醇对胎鼠脑新皮质神经干细胞凋亡的影响

目的探讨乙醇对胎鼠神经干细胞凋亡的影响。方法将妊娠14 d胎鼠脑新皮质来源的神经干细胞暴露于终浓度分别为0(对照)、25、50、100 mmol/L的乙醇培养基溶液3 d。采用Annexin V/PI法检测细胞早期和晚期凋亡情况,采用JC-1探针法检测线粒体膜电位的改变,并检测凋亡相关基因Bcl-2、Bax、Caspase-3 mRNA和蛋白的表达。结果与对照组比较,50、100 mmol/L乙醇染毒组神经干细胞的早期凋亡细胞率明显升高,差异有统计学意义(P0.05);而各浓度乙醇染毒组神经干细胞的晚期凋亡率无明显改变。且随着乙醇染毒浓度的升高,神经干细胞的早期凋亡细胞率呈上升趋势。仅100 mmol/L乙醇染毒组神经干细胞线粒体膜电位低于对照组,差异有统计学意义(P0.05)。与对照组比较,各浓度乙醇染毒组神经干细胞Bax mRNA的表达水平均上升,差异有统计学意义(P0.05);而Bcl-2和Caspase-3 mRNA的表达水平均无明显改变。且随着乙醇染毒浓度的升高,Bax mRNA表达量呈上升趋势。与对照组比较,50、100 mmol/L乙醇染毒组神经干细胞Bax蛋白的表达水平均升高,而Bcl-2/Bax蛋白的比值均降低,差异有统计学意义(P0.05);各浓度乙醇染毒组神经干细胞Bcl-2、Caspase-3蛋白的表达水平均无明显改变。结论乙醇可引起神经干细胞早期凋亡,其机制可能与线粒体损伤和Bax表达上调有关。     

Adverse effects of pesticides on biochemical and haematological parameters in Tunisian agricultural workers

Biomonitoring of effects in agricultural workers is necessary to assess the individual risk of handling pesticides. In this study, biochemical and haematological parameters were measured to evaluate the effects of exposure to these compounds in agricultural workers. The study was carried out in 110 workers and 97 control subjects. Several haematological and biochemical parameters were analysed. Assessment of haematological parameters revealed that the mean cell volume and haematocrit levels were significantly lower in workers than in controls (P=0.002 and 0.013, respectively), while mean corpuscular haemoglobin concentrations were higher in workers (P<0.001). There was also a significant inhibition of butyrylcholinesterase activity in workers compared with that in controls (P<0.001). Assessment of biochemical parameters further showed significantly higher activities of transferases, lactate dehydrogenase (P<0.001), alkaline phosphatase (ALP) (P=0.006) and creatine kinase (CK) (P<0.015), as well as higher levels of proteins (P<0.001), creatinine (P=0.001) and urea (P=0.001) in workers compared with controls, along with significantly higher uric acid levels (P=0.012). Furthermore, the number of years exposed to pesticides predicted higher activities of alanine aminotransferase, CK, ALP, as well as uric acid levels. Overall, chronic exposure to pesticides appeared to affect several biochemical parameters. These biomarkers seem to be indicative of adverse effects of pesticides in agricultural workers, confirming their use for routine monitoring of effects.     

Effects of predator cues on pesticide toxicity: toward an understanding of the mechanism of the interaction

Pesticide toxicity may be modified by a number of co-occurring environmental and ecological stressors. Coexposure to predator cues has been shown to potentiate and/or synergize toxicity of pesticides. However, the mechanisms behind these interactions are not well understood. Here we examine the effects of fish predator (bluegill, Lepomis macrochirus) cues on toxicity of five different pesticides to the freshwater cladoceran, Ceriodaphnia dubia. The purpose for examining patterns among pesticides was to test the idea that the mechanism of the interaction could be explained by a general stress response; that is, the interaction patterns would be similar regardless of the pesticide's mechanism of action [MOA]). Acute 96-h concentration-response experiments were conducted for pesticides with and without fish cues. Predator cues influenced the toxicity of pesticides and the interaction patterns varied among pesticides. Fipronil exhibited a synergistic interaction, while predator cues interacted antagonistically for bifenthrin and thiacloprid. Other compounds previously reported to potentiate toxicity (malathion) were found to act additively. The results demonstrate that factors such as pesticide bioavailability, K(OC) , and exposure concentration may be important for predicting the occurrence of these interactions and that patterns were not consistent among pesticides varying in MOA. Predator stress is an important component for structuring communities and ecosystem processes. Fully understanding how this process may interact with organic contaminants may best be achieved by examination at toxicokinetic and toxicodynamic scales.     

硒对氟致大鼠睾丸和附睾损害拮抗作用的研究

目的 研究和探讨硒对氟致雄性大鼠生殖损害的拮抗作用及其机理，找出硒牟氟毒性的最佳拮抗剂量。方法 给雄性大鼠饮用氟化钠（150mg／L）及同时分别加入不同浓度亚硒酸钠（0．5，2．0和4．0mg／L）的饮水共8周，观察氟及氟硒联合对大鼠血、尿氟水平有对睾丸和附睾的影响。结果 氟暴露大鼠血液和尿液氟浓度明显升高，血清和睾丸微量元素量异常、睾丸和附睾组织脂质过氧化物（LPO）含量增加、谷胱甘肽过氧化物酶（GSH－Px）和ATP酶活性显降低。2．0mg/L亚硒酸钠对大鼠尿氟排泄具有显促进作用，对氟致血清和睾丸微量元素异常改变具有一定调速作用，对氟致睾丸和附睾LPO含量升高及GSH－Px和ATP酶活性降低具有显拮抗作用，而0．5和4．0mg／L亚硒酸钠的作用较弱。结论 2．0mg／L亚硒酸钠是本实验条件下硒拮抗氟致睾丸和附睾损害的最佳剂量。