PCB153对PBDE-47致SH-SY5Y细胞氧化应激和8-羟基脱氧鸟苷含量的影响

目的探讨PCB153和PBDE-47单独及联合染毒对SH-SY5Y细胞氧化应激及8-羟基脱氧鸟苷(8-OHdG)含量的影响。方法设DMSO溶剂对照组,1、5、10μmol/LPBDE-47(低、中、高)单独染毒组和与5μmol/LPCB153联合染毒组及相应的抗氧化剂组(N-乙酰-L-半胱氨酸NAC100μmol/L),分别对SH-SY5Y细胞染毒24h。用荧光染料DCFH-DA标记法和高效液相色谱-电化学技术(HPLC-ECD)分别检测细胞内活性氧(ROS)水平和8-OHdG的含量。结果随着染毒剂量的增加,PBDE-47单独染毒组ROS水平有逐渐增高的趋势,但与对照组及其相应的PCB153联合组相比,ROS水平无明显差异(P>0.05)。中、高联合染毒组ROS水平与对照组相比显著增加(P<0.05),并显著高于相应的单独剂量染毒组(P<0.05),加入抗氧化剂后细胞内ROS水平明显下降(P<0.05),细胞内ROS水平与PBDE-47染毒剂量呈现剂量-效应关系;高剂量PBDE-47单独染毒组和中、高剂量联合染毒组8-OHdG的含量与对照组相比均有明显的增加(P<0.05),高剂量联合染毒组8-OHdG含量明显高于相应的单独染毒组(P<0.05),加入抗氧化剂后其细胞内8-OHdG含量明显下降(P<0.05)。细胞内ROS水平与8-OHdG含量呈正相关关系(r=0.895)。结论一定剂量的PBDE-47可致DNA氧化损伤,PCB153可增加PBDE-47对SH-SY5Y细胞DNA的氧化损伤作用,提示活性氧在PBDE-47致DNA损伤方面发挥了重要作用。     

PCB153对PBDE-47致SH-SY5Y细胞DNA损伤和修复基因表达的影响

目的探讨PCB153和PBDE-47单独及联合染毒对SH-SY5Y细胞DNA损伤及其修复基因表达的影响。方法设DMSO溶剂对照组,1、5、10μmol/LPBDE-47(低、中、高)单独染毒组和与5μmol/L PCB153联合染毒组及相应的抗氧化剂组(N-乙酰-L-半胱氨酸NAC100μmol/L),分别对SH-SY5Y细胞染毒24h。用单细胞凝胶电泳试验测定DNA损伤情况,用RealTime PCR检测DNA损伤修复酶XRCC1及XRCC3mRNA表达情况。结果中、高剂量单独染毒组和中、高剂量联合染毒组细胞尾部DNA百分率、Olive尾距均显著高于对照组(P<0.05),且呈现明显的剂量-效应关系,中、高联合染毒组细胞尾部DNA百分率、Olive尾距均显著高于相应的PBDE-47或PCB153单独染毒组(P<0.05),加入抗氧化剂后其细胞尾部DNA百分率及Olive尾距均明显下降(P<0.05),高剂量联合组对细胞DNA损伤具有交互作用(F=23.74,P<0.01);高剂量染毒组及中、高剂量联合染毒组XRCC1mRNA表达与对照组相比均明显下降(P<0.05),加入抗氧化剂后其XRCC1mRNA表达上升(P<0.05);高剂量单独和联合染毒组XRCC3mRNA表达与对照组相比均明显上升(P<0.05),加入抗氧化剂后可使XRCC3mRNA表达明显下降(P<0.05)。相关分析结果表明,细胞DNA损伤与XRCC1mRNA的表达呈负相关,与XRCC3mRNA的表达呈正相关(r分别为0.74,0.76,P<0.05)。结论一定剂量的PBDE-47可导致DNA损伤和影响DNA损伤修复基因的表达,PCB153可增强PBDE-47对细胞DNA的损伤作用,氧化应激可能在PBDE-47致DNA损伤过程中发挥了重要作用。     

PBDE-47单独和与PCB153联合染毒对大鼠神经发育的影响

目的探讨2,2’,4,4’-四溴联苯醚(2,2’,4,4’-tetrabromodiphenyl ethers,PBDE-47)单独和与2,2’,4,4’,5,5’六氯联苯(2.2’,4,4’,5,5’-hexachlorobiphenyl,PCB153)联合作用对 SD 大鼠学习记忆能力及海马 CA1区神经元超微结构的影响。方法将出生第10天清洁级 SD 大鼠随机分为1、5、10 mg/kg PBDE-47组、5 mg/kg PCB153组、1 mg/kg PBDE-47 5 mg/kg PCB153组、5 mg/kg PBDE-47 5 mg/kg PCB153组、10 mg/kg PBDE-47 5 mg/kg PCB153组和对照组(大豆油),每组18只,雌雄各半,按10 ml/kg 经口灌胃进行一次性染毒处理。在大鼠2个月龄时,进行 Morris 水迷宫实验和海马 CA1区神经元超微结构观察。结果低剂量组染毒大鼠(1 ms/ks PBDE-47组和1 mg/ks PBDE-47 5 mg/kg PCB153组)内质网和线粒体超微结构基本正常。随着染毒剂量的增加,内质网出现肿胀、扩张、脱颗粒,部分出现...     

2,2’,4,4’-四溴联苯醚对人神经母细胞瘤细胞自噬水平的影响

目的探讨2,2’,4,4’-四溴联苯醚(2,2’,4,4’-tetrabromodiphenyl ethers,PBDE-47)对人神经母细胞瘤SH-SY5Y细胞自噬水平的影响。方法取对数生长期的SH-SY5Y细胞,分别以终浓度为0(溶剂对照)、1、5、10μmol/L的PBDE-47染毒处理24 h后,采用透射电子显微镜观察细胞内双层膜自噬体结构;以自噬囊泡示踪剂单丹黄酰尸胺(MDC)染色检测自噬囊泡生成情况;采用Western blotting技术检测自噬相关蛋白LC3、Beclin1、P62的表达水平。结果电镜超微结构观察结果显示,对照组细胞内未见异常变化,1μmol/L染毒组细胞内可见轻微的线粒体扩张但未见明显的双层膜自噬体结构,5μmol/L染毒组细胞内可见明显的线粒体空泡及双层膜自噬体结构,10μmol/L染毒组细胞内观察到的双层膜自噬体结构最多;与对照组相比,5、10μmol/L PBDE-47染毒组MDC荧光强度升高,MDC阳性细胞比例增加;此外,5、10μmol/L PBDE-47染毒组自噬相关蛋白LC3、Beclin1、P62的表达水平与对照组相比均明显升高,且差异具有统计学意义(P0.05)。结论 PBDE-47可诱导SH-SY5Y细胞自噬水平的增加。     

2，2'，4，4'-四溴联苯醚对人神经母细胞瘤SH-SY5Y细胞胞内游离钙离子浓度的影响

目的 研究2,2',4,4'-四溴联苯醚（2,2',4,4'-tetrabromodiphenyl ethers,PBDE-47）对人神经母细胞瘤SH-SY5Y细胞胞内游离钙离子([Ca2+]i)浓度的影响。方法 取对数生长期的SH-SY5Y细胞,分别染毒终浓度为0（溶剂对照）、1、5、10 μmol/L的PBDE-4...     

PBDE-47和PCB153染毒致大鼠神经毒性作用

目的 探讨2,2',4,4'-四溴联苯醚(PBDE-47)和2,2',4,4',5,5'-六氯联苯(PCB153)单独或联合染毒对SD大鼠的神经毒性作用及其机制.方法 出生第10 d的SD大鼠经一次性PBDE-47[1,5,10 mg/(kg·bw)]和/或PCB153[5 mg/(kg·bw)]染毒,用Morris水迷宫试验观察2月龄大鼠空间学习、记忆能力;用实时荧光定量RT-PCR检测海马组织死亡相关蛋白激酶(DAPK)、X染色体连锁的凋亡抑制蛋白(XIAP)、含半胱氨酸的天冬氨酸酶-12(Caspase-12)、含半胱氨酸的天冬氨酸酶-3(Caspase-3)以及细胞色素(cytochrome C)等钙信号通路相关基因mRNA的表达水平.结果 随PBDE-47染毒剂量的增加,大鼠学习、记忆能力呈现减退的趋势,且所有染毒剂量组与对照组比较差异均有统计学意义(P<0.05).PCB153可增加PBDE-47的神经毒性作用.与对照组比较,10 mg/(kg·bw)染毒组PBDE-47可导致雌雄大鼠XIAP基因mRNA表达水平显著下调(P<0.05),同时使雌雄大鼠Caspase-12、Caspase-13、Cytochrome C以及雄性大鼠DAPK基因mRNA表达水平显著上调(P<0.05).除雌雄大鼠DAPK以及雌性大鼠Cytochrome基因外,PBDE-47和PCB153对雌雄大鼠其他各基因mRNA表达水平的影响具有交互作用(P<0.05).结论 PBDE-47可引起大鼠神经系统损伤,同时影响大鼠海马区钙信号诱导的凋亡相关基因mRNA表达水平,PCB153可增强PBDE-47的上述神经毒性作用.     

PBDE-47对INS-1细胞氧化应激和凋亡影响

目的 探讨2,2',4,4'-四溴联苯醚(PBDE-47)对大鼠胰岛细胞瘤细胞INS-1毒性作用及机制.方法 设3个PBDE-47剂量组(1、3、6μmol/L)和二甲基亚砜溶剂对照组,染毒INS-1细胞24h后,检测细胞存活率、凋亡率、活性氧(ROS)水平、丙二醛(MDA)含量、Fas和cytochrome C等凋亡相关基因表达水平.结果 与对照组比较,3、6 μmol/L PBDE-47组细胞存活率[(77.1±5.9)％和(27.5±10.6)％]均下降(P＜0.05);3、6μmol/L PBDE-47组ROS水平分别为(154.1 ±13.3)和(220.1±1.1),MDA含量分别为(26.1±1.0)和(32.7±2.5)μmol/L,6 μmol/LPBDE-47组细胞凋亡率为(38.4±4.2)％,与对照组比较均有增加(P＜0.05);与对照组比较,高剂量PBDE-47组Fas及cytochrome C基因表达水平均有增加(P＜0.05).结论 PBDE-47可诱导INS-1细胞凋亡,氧化应激和线粒体信号通路可能参与PBDE-47对INS-1细胞的毒性作用.     

2,2'''',4,4''''-四溴联苯醚对原代新生大鼠海马细胞氧化应激、DNA损伤和凋亡的影响

目的 探讨2,2',4,4'-四溴联苯醚(2,2',4,4'-tetrabromodiphenyl ethers,PBDE-47)对原代新生大鼠海马细胞氧化应激、DNA损伤和凋亡的影响.方法 原代培养的新生大鼠海马细胞暴露于10、20、40μg/ml PBDE-47,每组3个平行样,24h后,检测乳酸脱氢酶(LDH)漏出率,细胞内丙二醛(MDA)和还原型谷胱甘肽(GSH)含量、超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-Px)活力、活性氧(ROS)水平以及DNA损伤和细胞凋亡情况.结果 与对照组比较,20和40μg/ml组LDH漏出率升高,差异有统计学意义(P＜0.05).各染毒组MDA含量均高于对照组,GSH-Px活力均低于对照组,且20和40μg/ml组与对照组比较,差异均有统计学意义(P＜0.05);10、20、40μg/ml组GSH含量和SOD活力均低于对照组,差异有统计学意义(P＜0.05),但各染毒组之间差异无统计学意义(P＞0.05);20和40μg/ml组细胞内ROS水平高于对照组,差异均有统计学意义(P＜0.05).10、20、40μg/ml组尾部DNA百分率和Oliver尾矩均高于对照组,差异均有统计学意义(P＜0.05);20和40μg/ml组细胞凋亡率均高于对照组,差异有统计学意义(P＜0.05),且呈上升趋势.相关分析表明,海马细胞DNA损伤、凋亡百分率与ROS水平呈正相关(r值分别为0.982,0.998,P＜0.05),细胞凋亡百分率与DNA损伤呈正相关性(r=0.967,P＜0.05).结论 PBDE-47可致原代新生大鼠海马细胞氧化应激和诱导细胞DNA损伤和凋亡,呈现一定的神经毒性.     

2,2',4,4'-四溴联苯醚对SD大鼠生殖发育的影响

目的 探讨2,2',4,4'-四溴联苯醚(2,2',4,4'-tetrabromodiphenyl ethers,PBDE-47)对SD大鼠生殖发育的影响.方法 PBDE-47设3个剂量组(1、5、10 mg/kg.bw),大豆油为溶剂对照组,对出生后第10 d的清洁级(CL级)SD大鼠进行染毒.在大鼠出生后第10 d、30 d和60 d分别进行体重、身长和尾长的检测.在大鼠2月龄时,捕杀大鼠,测定睾丸、附睾、子宫和卵巢脏器系数;同时利用气相色谱-质谱联用仪检测血清中PBDE-47浓度;利用放射性免疫法对血清中睾酮(testosterone,Ts)和雌二醇(estradiol,E2)进行检测.结果 出生后第10 d、30 d和60 d的大鼠体重、身长和尾长与同期对照组相比较,差异无显著性(P>0.05).SD大鼠2月龄时,与对照组比较,5、10mg/kg染毒组血清PBDE-47水平仍较高,差异有统计学意义(P<0.05);与对照组比较,5、10 mg/kg染毒组卵巢脏器系数较高,差异有统计学意义(P<0.05);各染毒组睾丸、附睾和子宫脏器系数与对照组比较,差异无统计学意义(P>0.05);5、10 mg/kg染毒组血清Ts水平分别为(7.83±1.10)ag/ml、(9.41±0.08)ng/ml,与对照组比较,差异有统计学意义(P<0.01);各染毒组血清E2水平分别为(31.00 ±12.00)pg/ml、(38.50±11.50)pg/ml、(44.67±3.79)pg/ml,显著高于对照组,差异有统计学意义(P<0.05).结论 出生后第10 d一次性经口暴露于一定剂量的PBDE-47对大鼠生殖发育具有一定的影响.     

2,2’,4,4’-四溴联苯醚对SH-SY5Y细胞氧化应激与DNA损伤的影响

目的探讨2,2’,4,4’-四溴联苯醚(PBDE-47)对人神经母细胞瘤细胞株(SH-SY5Y)氧化应激的影响和DNA损伤作用。方法用含10%胎牛血清的DMEM培养基在37℃、5%CO2条件下培养SH-SY5Y细胞。当培养细胞处于对数生长期时,用1、2、4、6、8和10μg/mlPBDE-47进行染毒,24h后检测细胞存活率、细胞外乳酸脱氢酶(LDH)漏出率、超氧化物歧化酶(SOD)活性、还原型谷胱甘肽(GSH)和丙二醛(MDA)含量,以及DNA损伤情况。结果与对照组相比,1μg/ml和2μg/ml剂量组细胞存活率略有上升(P<0.05),4、6、8和10μg/ml剂量组细胞存活率显著降低(P<0.05);各染毒剂量组GSH含量显著下降(P<0.05)、尾矩显著上升(P<0.05);4、8和10μg/ml剂量组MDA含量明显高于对照组(P<0.05);4、6、8和10μg/ml剂量组LDH漏出率显著高于对照组(P<0.05)、SOD活力明显低于对照组(P<0.05);6、8和10μg/ml剂量组尾部DNA百分率与对照组比较存在差异的显著性(P<0.05)。结论PBDE-47可引起SH-SY5Y细胞氧化应激和DNA损伤,氧化应激可能在PBDE-47致DNA损伤中起重要作用。     

Toxic effect of PBDE-47 on thyroid development, learning, and memory, and the interaction between PBDE-47 and PCB153 that enhances toxicity in rats

Polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) are widespread environmental contaminants. There are potential interactive effects between PBDEs and PCBs, as these compounds share similar structures. The developmental neurotoxicity of 2, 2', 4, 4'-tetrabromodiphenyl ether (PBDE-47) and the interaction of PBDE-47 with 2, 2', 4, 4', 5, 5'-hexachlorobipheny (PCB153) were investigated herein, as the dominant congener forms of PBDEs and PCBs, respectively. SD rats were exposed to a single oral dose of PBDE-47 (1, 5, and 10 μg/g) and/or PCB153 (5 μg/g) on post-natal day (PND) 10. Concentrations of PBDE-47, triiodothyronine (T(3)), thyroxine (T(4)), and thyroid-stimulating hormone (TSH) in serum; organ-to-body weight ratios; as well as long-term learning and memory were measured in 2-month-old rats. The present study found that some doses of PBDE-47 decreased the organ-to-body weight ratios of the thyroid and uterus, decreased the concentration of T(4) in serum, and increased the organ-to-body weight ratio of the ovaries (p < 0.05). PCB153 could increase the action of PBDE-47 during combined exposure, but this interaction was not found between PBDE-47 and PCB153. In a Morris water maze experiment, the latency periods were significantly prolonged and time ratios were obviously depressed in all PBDE-47-treated groups compared to the control (p < 0.05); furthermore, significant interactions between PBDE-47 and PCB153 were observed (p < 0.05). In conclusion, PBDE-47 may depress thyroid development as well as the long-term learning and memory capabilities in adult rats exposed to PBDE-47 on PND 10. PCB153 can interact with PBDE-47, resulting in an increase in developmental neurotoxicity.     

多氯联苯对苯并[a]芘致HepG2细胞DNA损伤作用的影响

目的观察多氯联苯(PCBs)153和苯并[a]芘(B[a]P)单独及联合处理对人肝肿瘤细胞HepG2的DNA损伤作用。方法以HepG2细胞为靶细胞,以DMSO为溶剂对照,PCB153设4个剂量组:0.1、1、10和100μmol/L,B[a]P设4个剂量组:12.5、25、50和100μmol/L。应用单细胞凝胶电泳试验检测PCB153和B[a]P单独和联合处理对HepG2细胞DNA损伤的影响;通过荧光分光光度法分别测定PCB153对HepG2细胞CYP1A1(EROD)、CYP2B1(PROD)酶活性的影响。结果与溶剂对照相比,B[a]P各剂量组Olive尾矩均显著增加(P<0.01);而PCB153各剂量组均不引起Olive尾矩显著增加,与50μmol/LB[a]P单独作用相比,0.1~10μmol/L的PCB153与50μmol/LB[a]P联合作用可使Olive尾矩增加,但只有10μmol/L PCB153与50μmol/LB[a]P联合作用极显著增加Olive尾矩(P<0.01);100μmol/L PCB153与50μmol/LB[a]P联合作用与50μmol/LB[a]P单独作用相比,Olive尾矩则显著降低(P<0.01)。酶活性分析表明,PCB153各剂量组均可诱导EROD、PROD活性显著增加,差异有统计学意义。结论PCB153在一定浓度范围内使B[a]P诱导的HepG2细胞DNA损伤作用显著增强,可能与其诱导的CYP1A1、CYP2B1酶活性升高有关。     

多溴联苯醚对SH-SY5Y细胞氧化应激及凋亡的影响

目的观察2,2’,4,4’-四溴联苯醚(PBDE-47)对人神经母细胞瘤SH-SY5Y细胞株氧化应激和凋亡的影响及活性氧在细胞凋亡中的作用。方法实验共分4组,PDDE-47终浓度为0、2、4、8μg/ml,分别作为对照组,低、中、高剂量组。用2、4、8μg/ml PBDE-47对培养的SH-SY5Y细胞染毒,24 h后检测细胞存活率、活性氧(ROS)水平、丙二醛(MDA)含量及凋亡率。结果与对照组比较,低剂量组细胞存活率略有上升,中、高剂量组细胞存活率明显降低,差异有统计学意义(P相似文献   

Synergistic effect of 2,2',4,4',5,5'-hexachlorobiphenyl and 2,3,7,8-tetrachlorodibenzo-p-dioxin on hepatic porphyrin levels in the rat.

We studied the effect of polychlorinated biphenyls (PCBs) on hepatic porphyrin accumulation in female Sprague-Dawley rats by feeding them diets containing 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 2,2',4,4',5,5'-hexachlorobiphenyl (PCB 153), 2,3,3',4,4',5-hexachlorobiphenyl (PCB 156), 3,3',4,4',5-pentachlorobiphenyl (PCB 126), or combinations of the single PCB congeners with TCDD for 13 weeks. A dose-dependent increase in hepatic porphyrin accumulation occurred after TCDD, PCB 126, or PCB 156 administration, reaching maximal levels of about twice control values. The lowest dose levels for which a significant increase in hepatic porphyrin accumulation was found were 0.7 microgram TCDD/kg diet, 50 micrograms PCB 126/kg diet, or 6 mg PCB 156/kg diet. These doses are equivalent to 47 ng TCDD/kg/day, 3.2 micrograms PCB 126/kg/day, and 365 micrograms PCB 156/kg/day. Relative potencies for hepatic porphyrin accumulation, using TCDD as a reference, ranged from 0.015 to 0.06 for PCB 126 and from 0.0001 to 0.0003 for PCB 156. CYP1A2 activities significantly correlated with hepatic porphyrin levels, with coefficients of 0.629, 0.483, or 0.808 for TCDD, PCB 126, or PCB 156, respectively. Administration of PCB 153 alone did not result in hepatic porphyrin accumulation. Co-administration of PCB 153 and TCDD revealed a strong synergistic effect on porphyrin accumulation (about 800 times control levels). This synergistic effect was significant in rats fed diets containing any combination of PCB 153 with TCDD. Uroporphyrin III and heptacarboxylic porphyrin were accumulated in porphyrinogenic livers. These results suggest that TCDD induction of CYP1A2 may be involved, leading to oxidation of uroporphyrinogen III to uroporphyrin III, in combination with an increase in delta-aminolevulinic acid synthetase induced by PCB 153. Under porphyrinogenic conditions, an inhibitor of CYP1A2 activity may also be formed. The interactive effects on porphyrin accumulation after co-administration of dioxinlike and non-dioxinlike compounds may have significant implications for the risk assessment of these chemicals.     

Plasma concentrations of selected organobromine compounds and polychlorinated biphenyls in postmenopausal women of Québec, Canada

BACKGROUND: Brominated flame retardants, especially polybrominated diphenyl ethers (PBDEs), have been widely used in North America, but little is known about the level of exposure of human populations to these compounds. OBJECTIVES: We set out to assess the internal exposure of postmenopausal Canadian women to selected organobromine compounds and to investigate factors associated with this exposure. METHODS: We measured concentrations of four PBDEs, one polybrominated biphenyl, and for comparative purposes, 41 polychlorinated biphenyl (PCB) congeners in plasma samples from 110 healthy postmenopausal women who were recruited at a mammography clinic in 2003-2004. RESULTS: PBDE-47 was the major PBDE congener, with a mean (geometric) concentration of 8.1 ng/g lipids and extreme values reaching 1,780 ng/g. By comparison, the mean concentration of the major PCB congener (PCB-153) was 41.7 ng/g and the highest value was 177 ng/g. PBDEs 47, 99, and 100 were strongly intercorrelated, but weaker correlations were noted with PBDE-153. As the sum of PBDEs (summation operatorPBDEs) increased, the relative contribution of PBDE-47 to the summation operatorPBDEs increased, whereas that of PBDE-153 decreased. PBDE-153 was the only brominated compound correlated to PCB-153. PBDE levels were not linked to any sociodemographic, anthropometric, reproductive, or lifestyle variables documented in the present study. Age and body mass index gain since the age of 18 years were significant predictors of PCB-153 plasma levels. CONCLUSION: Our results suggest that exposure to PBDE-47 likely occurs through direct contact with the penta-PBDE formulation, whereas exposure to PBDE-153 may originate in part from the food chain.     

亚硝酸钠诱导L929细胞增殖毒物兴奋效应

目的采用体外细胞毒性检测方法研究亚硝酸钠(NaNO2)对L929细胞增殖的影响,探讨在此过程中遗传物质的损伤情况。方法体外培养L929细胞,用溴化四氮唑蓝法检测不同浓度NaNO2对细胞增殖的影响;并采用单细胞凝胶电泳技术及KCl-十二烷基磺酸钠沉淀法(K-SDS)检测NaNO2对L929细胞DNA损伤及DNA-蛋白质交联的作用。结果 NaNO2处理L929细胞48h后,细胞增殖出现毒物兴奋效应(hormesis),其剂量范围约为0～0.0384mg/L;染毒剂量为0.02、1 500 mg/L时,细胞尾长分别为(2.72±1.99)、(3.26±3.09)μm,尾DNA%分别为(7.87±6.63)%及(7.75±4.90)%,Olive尾矩分别为(0.80±0.64)及(0.79±0.64),与阴性对照组〔(1.83±1.08)μm、(6.07±3.59)%、(0.43±0.28)〕比较,差异均有统计学意义(P<0.05);2、20、1 500 mg/L剂量组的DNA-蛋白质交联系数大于阴性对照组(P<0.05),且呈现剂量-效应关系。结论 NaNO2可诱导L929细胞出现毒物兴奋效应,并且在其剂量范围内可诱导细胞遗传物质的断裂性损伤。