邻苯二甲酸单甲酯对大鼠血液生化指标的影响及毒理研究

高旭1,于霞2,李信薇1,池振兴1,3,*

1. 哈尔滨工业大学(威海)海洋科学与技术学院,威海 264209 2. 威海环境再生能源有限公司,威海 264200 3. 浙江省污染暴露与健康干预重点实验室,杭州 310015

摘要:随着塑化剂邻苯二甲酸酯的大量使用,其代谢产物邻苯二甲酸单酯普遍存在于环境中。目前,邻苯二甲酸酯类代谢物(mPAEs)对生物体的危害已引起广泛关注,然而其对血液的毒性效应还不明确。本研究以邻苯二甲酸单甲酯(MMP)为对象,选用Sprague-Dawley(SD)大鼠为实验动物,通过检测大鼠血液中血细胞数量和血液生化指标考察MMP(低剂量50 mg·kg-1、中剂量250 mg·kg-1、高剂量500 mg·kg-1)的血液毒性,并从氧化应激的角度探究机制。结果表明:(1)染毒3 h后,3个剂量染毒组SD大鼠血液中的红细胞和白细胞数量均低于对照组。其中,高剂量组二者数量较对照组分别下降9.13%和43.56%。对于淋巴细胞和中性粒细胞数目,高剂量组二者分别比对照组低26.4%和30.7%。这说明MMP会使血细胞减少,进而会损害血液的携氧和免疫等功能。(2)染毒24 h(禁食12 h)和连续染毒7 d后,3个剂量MMP均使大鼠血清中总胆固醇和总蛋白含量较对照组有所下降;染毒24 h后,高剂量MMP使二者分别降低36.67%和18.25%;连续染毒7 d后,高剂量组二者分别降低43.97%和26.35%。与对照组相比,3个剂量MMP染毒组的大鼠血浆中尿素氮含量及血清中酸性磷酸酶活性在染毒24 h后均降低,高剂量MMP使二者分别下降34.33%和41.37%;连续染毒7 d后,高剂量组二者分别比对照组降低28%和31.43%。这说明MMP会对血脂的新陈代谢以及肾、肝功能产生影响。(3)染毒3 h后,随着MMP剂量的增加,大鼠血液中超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性均呈现下降趋势,高剂量组二者活性较对照组分别下降17.5%和58%。3个剂量MMP使丙二醛(MDA)含量均高于对照组,其中低剂量组MDA含量比对照组高70%。这说明MMP会破坏机体氧化抗氧化平衡,引发氧化应激反应。

关键词:邻苯二甲酸单甲酯;SD大鼠;血液毒性;血细胞;血液生化指标;氧化损伤

邻苯二甲酸酯类(phthalate esters, PAEs)能够增加塑料制品的可塑性[1],其在工业生产过程中常作为增塑剂被应用于医疗器械、洗涤护理产品、清洁剂、化妆品和食品包装等各个领域[2],与人们日常生活息息相关。相关产品在生产、使用和处置过程中,可不断释放PAEs到环境中[3],污染土壤[4]、水体[5]和大气[6]。环境中的PAEs能够通过皮肤接触、呼吸和进食等多种途径进入人体[7-8],危害机体健康。血液是人体极其重要的组织,具有携氧、免疫、物质运输、调节体温及信息传递等多种功能。进入人体的部分PAEs会被血液吸收,并在内源性酯酶的作用下被水解代谢为相应的邻苯二甲酸单酯(mPAEs)[9]。此外,环境中的mPAEs也能以各种方式进入生物体血液[10-12]。研究人员已经在男性血液、母血和脐带血中检测到了mPAEs的存在[13-14]。存在于血液中的PAEs及其代谢产物随血液循环被输送到全身各处,损害体内的组织和器官,引发疾病。

目前,关于PAEs及其代谢产物毒性的研究主要集中在生殖发育、神经和遗传等方面[15-21],涉及血液毒性及其作用机制的研究鲜有报道,且研究对象主要针对分子量较大、毒性较强的邻苯二甲酸二(2-乙基己基)酯(DEHP)、邻苯二甲酸二正丁酯(DBP)、邻苯二甲酸丁苄酯(BBP)及其代谢产物邻苯二甲酸单(2-乙基己基)酯(MEHP)、邻苯二甲酸单丁酯(MBP)、邻苯二甲酸单苄酯(MBzP)。张弘等[22]的研究表明,DEHP(500 mg·kg-1)亚慢性染毒90 d会使大鼠白细胞、红细胞数量及血红蛋白含量显著下降。另有研究表明,MEHP也与血液中血红蛋白含量的下降有关[23-24]。Sicińska[25]通过体外实验发现,DBP、BBP(25 μg·mL-1)及其代谢产物MBP、MBzP(250 μg·mL-1)会使红细胞出现溶血现象。此外,DBP、BBP、MBP和MBzP还会增加离体红细胞中活性氧(ROS)含量,改变其抗氧化酶(超氧化物歧化酶(SOD)、过氧化氢酶(CAT))活性,使胞内高铁血红蛋白(MetHb)含量升高[26]

邻苯二甲酸二甲酯(dimethyl phthalate, DMP)作为一种分子量较低的PAEs已经被列入我国优先污染物黑名单[27],其一级代谢产物邻苯二甲酸单甲酯(monomethyl phthalate, MMP)具有急性毒性、致畸和致癌活性[28-29]。目前,DMP和MMP在人体的各种体液中均已被检测到[30-32]。Babu-Rajendran等[33]采用气相色谱-质谱联用法测定了人体尿液中的PAEs,发现尿液中DMP的浓度范围为nd~141 ng·mL-1。陈甘讷等[34]的研究表明,MMP在孕妇分娩后母血和脐血中的浓度分别为1.89~2.07 μg·L-1和2.41~2.67 μg·L-1。针对研究现状的不足,本实验选取MMP(DMP的代谢产物)为研究对象,以Sprague Dawley(SD)大鼠为受试动物,通过检测血细胞(红细胞、白细胞、淋巴细胞和中性粒细胞)数量、血液生化指标(总胆固醇、尿素氮、总蛋白和碱性磷酸酶)以及氧化应激水平(抗氧化酶SOD、CAT和丙二醛(MDA))以探究MMP(50、250和500 mg·kg-1)对大鼠血液的毒性影响及作用机制,有助于完善PAEs类代谢物对血液毒性效应的研究,为其风险评价和相关疾病预防提供科学依据。

1 材料与方法(Materials and methods)

1.1 主要仪器设备与试剂耗材

主要仪器设备:动物版血液分析仪(HF-3800,济南汉方医疗器械有限公司,中国)、紫外-可见分光光度计(岛津UV-1700,Shimadzu,日本)、离心沉淀机(80-2,上海荣泰生化有限公司,中国)、数显恒温水浴锅(HH-S,常州翔天实验仪器厂,中国)、旋涡混合器(XH-C,金坛市白塔新宝仪器厂,中国)、电热鼓风干燥箱(101-00A,上海路韵仪器设备有限公司,中国)。

主要试剂耗材:邻苯二甲酸单甲酯(MMP;分析纯,国药集团化学试剂有限公司,中国)、乙酸(冰醋酸;分析纯,国药集团化学试剂有限公司,中国)、肝素钠(heparin sodium salt;185 USP units·mg-1,上海麦克林生化科技有限公司,中国)、长寿花金胚玉米油(山东三星玉米产业科技有限公司,中国);总超氧化物歧化酶(total superoxide dismutase, T-SOD)测试盒、过氧化氢酶(catalase, CAT)测试盒、丙二醛(malonicdialdehyde, MDA)测试盒、总胆固醇(total cholesterol, T-CHO)测试盒、尿素氮(BUN)测试盒、总蛋白(total protein, TP)定量试剂盒、酸性磷酸酶(acid phosphatase, ACP)试剂盒(南京建成生物工程研究所,中国)。

1.2 实验动物

本研究选用的SD大鼠购自正规畜牧中心,所有大鼠均健康。在实验过程中,大鼠被饲养在实验室动物房中,温度控制在18~25 ℃,相对湿度控制在(55±5)%,接受正常光照,可自由获取标准动物饲料和经过滤的自来水。按照本地法规进行动物实验。

1.3 实验方法

1.3.1 SD大鼠染毒及采血

设置3个不同剂量的染毒组(低剂量50 mg·kg-1、中剂量250 mg·kg-1、高剂量500 mg·kg-1)和对照组,每组选用3只SD大鼠,按照体质量计算出每只大鼠灌胃所需MMP质量,用玉米油配成1.5 mL染毒液,对大鼠灌胃染毒。对照组灌胃等量的1.5 mL玉米油。

染毒结束后,用固定器将SD大鼠固定,在鼠尾中下部涂抹75%酒精消毒,用5.5号静脉输液针扎入静脉采集所需血液。

1.3.2 血细胞检测

将SD大鼠灌胃染毒3 h后,从尾部采集血液至EDTA-K2抗凝管中,使用HF-3800动物版血液分析仪的全血模式检测血液中红细胞、白细胞、淋巴细胞和中性粒细胞的数量,记录检测结果。

1.3.3 血液生化指标检测

对SD大鼠灌胃染毒24 h(禁食12 h)和连续染毒7 d(每天同一时间灌胃染毒)后,从大鼠尾部取全血于离心管中,以3 000 r·min-1将血样离心15 min,取上层血清用于检测血液中总胆固醇、总蛋白的含量及酸性磷酸酶的活性。从大鼠尾部采取染毒24 h和连续染毒7 d后的全血于肝素抗凝离心管中,在3 000 r·min-1条件下离心15 min,取上层血浆用于检测血液中的尿素氮含量。根据总胆固醇、尿素氮、总蛋白和酸性磷酸酶试剂盒说明书上的操作步骤,使用紫外-可见分光光度计检测。

1.3.4 血液氧化应激水平检测

对SD大鼠灌胃染毒3 h后,从尾部取全血于离心管中。将血样以3 000 r·min-1离心15 min,取上层血清用于检测血液中SOD、CAT活性和MDA含量。根据SOD、CAT和MDA试剂盒说明书上的操作步骤,使用紫外-可见分光光度计检测。

1.4 数据分析

用Origin 2018和SPSS 25.0软件计算平均值和标准差,对各组红细胞、白细胞、中性粒细胞和淋巴细胞等血细胞数量,总胆固醇、尿素氮、总蛋白的含量和酸性磷酸酶活性等血液生化指标,以及SOD、CAT的活性和MDA含量等氧化应激指标之间的差异性进行单因素方差分析(One-Way ANOVA),方差齐性采用LSD检验,并绘制柱状图。

2 结果(Results)

2.1 MMP对SD大鼠血液中血细胞数量的影响

染毒3 h后,MMP对大鼠血液中红细胞、白细胞、淋巴细胞和中性粒细胞的毒性影响如表1所示。统计分析表明,随着MMP剂量的增加,SD大鼠血液中红细胞、白细胞、淋巴细胞和中性粒细胞数量总体上均呈现下降趋势。低、中、高剂量染毒组红细胞数量与对照组相比分别下降1.11%、4.7%和9.13%,但均无显著差异(P>0.05)。淋巴细胞和中性粒细胞数量呈现低剂量兴奋效应[35],高剂量组白细胞、淋巴细胞和中性粒细胞数量与对照组相比分别下降43.57%、30.7%和26.44%,均有显著性差异(P<0.05)。这表明,MMP会导致大鼠血液中的血细胞数量出现不同程度的降低。

表1 不同剂量邻苯二甲酸单甲酯(MMP)染毒3 h后对SD大鼠血液中血细胞数量的影响
Table 1 The number of blood cells of SD rats after monomethyl phthalate (MMP) exposure for 3 h

血细胞种类Types of blood cellsMMP剂量/(mg·kg-1)MMP dose/(mg·kg-1)050250500RBC/(1012个·L-1)10.84±0.8310.72±1.27(↓1.08%)10.33±0.76(↓4.67%)9.85±0.94(↓9.13%)WBC/(109个·L-1)16.87±1.1216.62±1.33(↓1.46%)11.23±1.79*(↓33.4%)*9.52±0.24*(↓43.56%)*LYM/(109个·L-1)10.34±0.9811.25±0.26(↑8.83%)9.72±0.88(↓6.03%)7.17±0.32*(↓30.66%)*GRA/(109个·L-1)3.48±0.383.76±0.53(↑7.95%)2.99±0.34(↓13.98%)2.56±0.30*(↓26.34%)*

注:RBC表示红细胞,WBC表示白细胞,LYM表示淋巴细胞,GRA表示中性粒细胞;↑或↓表示与对照组相比上升或下降的百分比;*表示染毒组与对照组有显著性差异(P<0.05)。

Note: RBC stands for red blood cell, WBC stands for white blood cell, LYM stands for lymphocyte, and GRA stands for granulocyte; ↑ or ↓ indicates the percentage increase or decrease compared with the control group; *indicates significant difference from the control (P<0.05).

2.2 MMP对SD大鼠血液生化指标的影响

染毒24 h和连续染毒7 d后,MMP对大鼠血液总胆固醇、尿素氮、总蛋白含量和酸性磷酸酶活性的影响如图1所示。

图1 不同染毒时间下MMP对SD大鼠血液生化指标的影响
注:T-CHO表示总胆固醇,BUN表示尿素氮,TP表示总蛋白,ACP表示酸性磷酸酶;*表示染毒组与对照组有显著性差异(P<0.05)。
Fig. 1 Blood biochemical indexes of SD rats after MMP exposure for different time
Note: T-CHO stands for total cholesterol, BUN stands for blood urea nitrogen, TP stands for total protein, and ACP stands for acid phosphatase;
* indicates significant difference from the control (P<0.05).

随着MMP剂量增大,大鼠血液中总胆固醇含量均呈现出下降趋势,且连续染毒7 d后下降得更快(图1(a))。染毒24 h后,低、中、高剂量组总胆固醇含量分别下降17.47%、31%和36.67%,与对照组相比均差异显著(P<0.05)。连续染毒7 d后,与对照组相比,低、中、高剂量组总胆固醇含量分别下降22.97%、37.4%和43.97%,均有显著差异(P<0.05)。连续染毒7 d后,各剂量组总胆固醇含量均比染毒24 h后低,且500 mg·kg-1剂量下总胆固醇含量为最低。这表明,摄入MMP的时间越久、剂量越大总胆固醇含量降低越快,对血液损害越大。

MMP均会导致血液中尿素氮含量减少,且总体呈现下降趋势(图1(b))。其中,染毒24 h后,低、中、高剂量组尿素氮含量和对照组相比差异均显著(P<0.05),分别下降15.97%、26.43%和34.33%。连续染毒7 d后,尿素氮含量呈现低剂量兴奋效应,中、高剂量MMP使尿素氮含量较对照组分别下降22.13%和28%,差异显著(P<0.05)。这表明,短时间摄入不同剂量MMP均会使大鼠血液尿素氮含量减少;而长时间摄入低剂量MMP时,大鼠血液尿素氮含量会升高;MMP剂量增大后,血液中尿素氮含量会减少。

血液中总蛋白含量均随着MMP剂量增加而减少,呈下降趋势,但连续染毒7 d后下降趋势较慢(图1(c))。其中,高剂量MMP染毒24 h和连续染毒7 d后,总蛋白含量分别减少18.25%和26.35%,与对照组相比差异显著(P<0.05);连续染毒7 d后高剂量组的总蛋白含量最低。这表明,长时间高剂量摄入MMP会使大鼠血液总蛋白含量大幅降低。

MMP能使大鼠血液中酸性磷酸酶活性下降(图1(d))。其中,染毒24 h后,血液中酸性磷酸酶活性随着MMP染毒剂量的增加而下降,低、中、高剂量组较对照组分别显著下降10.63%、19.93%和41.37%(P<0.05)。连续染毒7 d后,低剂量组酸性磷酸酶活性与对照组相比显著上升27.4%(P<0.05),呈现低剂量兴奋效应;中、高剂量MMP分别使酸性磷酸酶活性显著下降21.87%和31.43%(P<0.05)。这表明,无论短时间还是长时间,摄入MMP剂量越大,大鼠血液中酸性磷酸酶活性越低。

2.3 MMP染毒后SD大鼠血液氧化应激水平

不同剂量MMP染毒3 h后,大鼠血液中SOD、CAT相对活性及MDA相对含量如图2所示。

随着MMP剂量增加,SOD活性呈下降趋势(图2(a))。与对照组相比,低、中、高剂量MMP使SOD活性分别下降3.6%、11.7%和17.5%(P>0.05)。这表明,MMP能够抑制SOD活性,但影响较小。

各剂量MMP对大鼠染毒3 h后,血液中CAT活性均低于对照组,且随着MMP剂量的增加呈现下降趋势(图2(b))。低、中、高剂量染毒组CAT活性与对照组相比分别下降19.57%、24.13%和57.68%(P<0.05)。这表明,MMP会使CAT活性下降,损害血液的抗氧化防御体系。

图2 不同剂量MMP染毒3 h后大鼠血液氧化应激水平
注:SOD表示超氧化物歧化酶,CAT表示过氧化氢酶,MDA表示丙二醛;*表示染毒组与对照组有显著性差异(P<0.05)。
Fig. 2 Oxidative stress level in the blood of SD rats after MMP exposure for 3 h
Note: SOD stands for superoxide dismutase, CAT stands for catalase, and MDA stands for malonic dialdehyde;
*indicates significant difference from the control (P<0.05).

不同剂量染毒组MDA含量均高于对照组,且均有显著差异(P<0.05) (图2(c))。与对照组相比,低、中、高剂量组MDA含量分别升高70.43%、59%和34.8%。这表明,MMP进入机体后能够诱导血液发生氧化应激反应,引起血液MDA含量升高。

3 讨论(Discussion)

3.1 MMP对SD大鼠血液功能的影响

血液是机体重要的组织,由血细胞和血浆组成,具有携氧、免疫等功能。血细胞包括红细胞、白细胞和血小板。大量研究证实,红细胞的主要功能是运输氧气和二氧化碳[36-37],同时还具有免疫功能,参与免疫应答调节[38-39]。白细胞是血液中执行免疫功能最主要的细胞[40],其能够通过吞噬细菌等途径来抵御和杀死入侵的病原体[41],对机体防御系统的建立有重要意义。淋巴细胞和中性粒细胞均属于白细胞,分别在机体特异性和非特异性免疫功能方面发挥重要作用[41-43]

已有研究表明,PAEs会造成血细胞数目下降,影响机体的免疫功能[44],但对其代谢物的影响仍不明确。本研究结果显示,MMP(DMP的代谢产物)会对血液中红细胞、白细胞、淋巴细胞及中性粒细胞造成不同程度的损伤,使其数目下降;且随着MMP剂量的增大,细胞数目下降愈发明显(表1)。这表明,作为PAEs类代谢物MMP也会使血液中的血细胞数量减少,进而造成血液的携氧和免疫等功能下降。

临床上,红细胞、白细胞、淋巴细胞和中性粒细胞也常作为诊断病理变化的重要依据。红细胞数量下降意味着机体可能出现贫血、白血病等疾病;白细胞数目减少代表机体的造血功能出现障碍;淋巴细胞数目偏低会导致机体免疫缺陷;中性粒细胞数量减少表明机体受到化学损伤,出现骨髓造血异常等疾病。由此推测,MMP会影响血液的携氧和免疫等功能,进而可能会引发机体出现贫血、免疫缺陷及骨髓造血功能障碍等疾病。

3.2 MMP对SD大鼠血脂代谢、肾、肝功能的影响

总胆固醇是反映机体内脂肪代谢水平的一项重要指标[45],其含量过多过少都会对机体产生危害。Zhu等[46]研究发现PAEs类代谢物会使胆固醇含量下降。本研究也得到了相似的结果,无论短时间还是长时间摄入MMP,机体血液总胆固醇含量均呈现下降趋势(图1(a))。这表明,MMP会影响血液中脂质的新陈代谢水平。

尿素氮是蛋白质代谢的终末产物,其常作为机体肾功能评价的重要指标[47]。在正常情况下,尿素氮会被肾小球滤过排出体外,若其含量偏低则代表着肾功能失调,含量偏高则意味着过滤功能可能失效,造成器质性肾功能损害。本研究中,机体摄入MMP后,血液中尿素氮含量下降(图1(b))。这表明,MMP会影响机体肾功能,导致其功能失调。

总蛋白含量能够反映肝脏的合成功能以及储备能力[48]。酸性磷酸酶也是描述机体肝功能的一个重要指标[49]。本研究发现,MMP会使血液中总蛋白含量以及酸性磷酸酶活性下降(图1(c)、图1(d))。总蛋白含量下降可能是因为机体摄入MMP后使肝细胞受损,肝脏合成功能出现障碍,最终导致其合成蛋白质减少。由于PAEs类代谢物具有亲脂性容易渗入膜脂质[50],因此推测酸性磷酸酶活性下降可能是因为MMP与溶酶体膜相互作用,抑制了酸性磷酸酶的释放,也可能因为MMP妨碍了溶酶体和质膜的融合,阻止酸性磷酸酶分泌到胞外而导致其活性下降[51]。总蛋白含量和酸性磷酸酶活性下降均反映出MMP对肝功能有一定影响。由于肝脏是胆固醇和尿素氮合成的主要场所,因此推测两者含量的下降也可能是肝功能受损造成的[52-53]

综上所述,机体摄入MMP后,会导致血脂代谢能力以及肾、肝功能受损。临床上,总胆固醇含量偏低意味着机体可能出现肝硬化、贫血等疾病。尿素氮含量减少表明机体肾功能出现障碍且可能有严重的肝脏疾病。总蛋白含量偏低代表机体可能患有肾炎、肝炎和肝硬化等疾病。酸性磷酸酶活性下降代表机体可能患有贫血、肾炎等疾病。本研究中,4个指标相互印证,且与3.1推测相吻合,因此MMP可能会诱导机体出现贫血、肾炎、肾功能障碍、肝炎和肝硬化等疾病。

3.3 MMP对SD大鼠血液抗氧化能力的影响

氧化应激(oxidative stress, OS)是指机体氧化与抗氧化平衡被破坏,生成过多的氧自由基而无法被清除,从而对机体产生的一种负面作用[54]。由于氧自由基可以直接或间接氧化DNA、脂质和蛋白质,诱发基因突变、脂质过氧化以及蛋白质变性,因此氧化应激通常被认为是污染物对机体产生毒性的作用机制之一[55]。已有研究表明,苯、四氯化碳及重金属铅、镧、钛等污染物能够通过氧化应激引起机体造血、肾、肝功能受损,进而诱发贫血、造血功能障碍、肾炎、肾功能失调以及肝炎、肝硬化等疾病[56-60]。因此,笔者从氧化应激的角度探究MMP对大鼠血液、肾、肝损伤的可能作用机制。

SOD和CAT作为机体抗氧化酶系极其重要的组成部分,其存在可以减轻氧化应激产生的损伤[61]。其中,SOD能够催化超氧阴离子进行歧化反应[62],清除有害的超氧化物自由基;CAT能够催化过氧化氢将其迅速转化为无害或毒性较小的物质[63],防止过氧化氢过多积累对机体造成损伤。本研究发现,机体摄入MMP后会使血液中SOD和CAT活性下降,且随着MMP剂量的增加,SOD和CAT活性呈现出下降趋势(图2(a)、图2(b))。这表明,MMP能够抑制血液中抗氧化酶SOD和CAT的活性,进而损害血液的抗氧化系统。

MDA作为脂质过氧化物的产物,其含量的多少可以反映出机体氧化损伤的程度[64]。本研究发现,各剂量MMP染毒组的MDA含量均高于对照组(图2(c))。这表明,机体摄入MMP后导致血液抗氧化防御体系受损,清除自由基的能力下降,引起氧化应激反应,对血液造成损伤。Holland等[65]研究发现妇女妊娠期尿液中的某些PAEs类代谢物会引起8-异丙醇烷(脂质过氧化的生物标志物)水平升高,使机体发生抗氧化损伤及氧化应激反应。本研究结果与之相符。

综上所述,MMP作为PAEs类代谢物的一种,会使血液的抗氧化能力下降,诱发氧化应激反应,从而对血液中血细胞以及血液生化指标产生影响,损害血液的携氧、免疫等功能;血脂的代谢能力以及机体的肾、肝功能,推测MMP进而可能引发机体发生贫血、造血功能障碍、肾功能失调以及肝硬化等相关疾病。本研究有助于明确邻苯二甲酸酯类代谢物对血液的毒性效应,并为其潜在的风险评估和相关疾病的预防提供一定的理论指导。

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Effects of Monomethyl Phthalate on Blood Biochemical Indicators of Rats and Its Toxicology

Gao Xu1, Yu Xia2, Li Xinwei1, Chi Zhenxing1,3,*

1. School of Marine Science and Technology, Harbin Institute of Technology, Weihai, Weihai 264209, China 2. WeiHai Waste-to-energy Co. Ltd., Weihai 264200, China 3. Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Hangzhou 310015, China

Abstract:With the extensive use of plasticizer phthalate, its metabolites, phthalate monoesters easily find their way to the environment. At present, the harm of phthalate metabolites (mPAEs) to organisms has attracted widespread attention; however, its toxic effect on blood remains unclear. In this study, tests on rat blood encompassing blood cell, blood biochemical indicator and oxidative stress analyses were conducted in order to explore the toxicity mechanism of monomethyl phthalate (MMP) at low dose 50 mg·kg-1, medium dose 250 mg·kg-1, high dose 500 mg·kg-1. The results show that: (1) After exposure for 3 h, the number of red and white blood cells in the three exposure groups was lower than that of the control group, with a decrease by 9.13% and 43.56%, respectively, in the high-dose group. For lymphocytes and neutrophils, a decrease of 26.4% and 30.7% was observed. We concluded that MMP leads to a decrease in blood cells, thus damaging the blood’s oxygen-carrying and immune functions. (2) After exposure for 24 h (fasting for 12 h) and continuous exposure for 7 d, the total contents of cholesterol and protein decreased after treatment, with 36.67% and 18.25% reductions in the high-dose group after 24 h exposure, respectively. After continuous exposure for 7 d, the two descriptors in the high-dose MMP group decreased by 43.97% and 26.35%, respectively. Compared with the control group, the plasma urea nitrogen content and serum acid phosphatase activity of rats in the three MMP dose exposure groups decreased after 24 h of exposure. The two in the high-dose MMP group decreased by 34.33% and 41.37%, respectively. Meanwhile, the two of the high-dose group decreased by 28% and 31.43% compared with the control group after continuous exposure for 7 d, respectively. These demonstrated that MMP could affect the metabolism of blood lipids and kidney and liver functions. (3) After exposure for 3 h, the activity of superoxide dismutase (SOD) and catalase (CAT) in the blood of rats showed a downward trend with the increase of MMP dose. Compared with the control group, the two features in the high-dose group decreased by 17.5% and 58%, respectively. The malondialdehyde (MDA) content in the three MMP dose groups was higher than that in the control group. Among them, the MDA content in the low dose group increased by 70% than that in the control group. These results indicated that MMP could disturb the redox balance, triggering oxidative stress.

Keywords:monomethyl phthalate; SD rat; hematotoxicity; blood cells; blood biochemical indicators; oxidative stress

收稿日期2021-11-12 录用日期:2022-01-01

基金项目山东省自然科学基金(ZR2022MB081);浙江省污染暴露与健康干预重点实验室开放基金(20220206);国家自然科学基金青年基金(21707026)

第一作者高旭(1998—),女,硕士研究生,研究方向为环境污染与健康,E-mail: 285639563@qq.com

*通信作者(Corresponding author), E-mail: zhenxingchi@hit.edu.cn

DOI:10.7524/AJE.1673-5897.20211112001

高旭, 于霞, 李信薇, 等. 邻苯二甲酸单甲酯对大鼠血液生化指标的影响及毒理研究[J]. 生态毒理学报,2022, 17(6): 389-399

Gao X, Yu X, Li X W, et al. Effects of monomethyl phthalate on blood biochemical indicators of rats and its toxicology [J]. Asian Journal of Ecotoxicology, 2022, 17(6): 389-399 (in Chinese)

文章编号:1673-5897(2022)6-389-11

中图分类号:X171.5

文献标识码:A

Received 12 November 2021

accepted 1 January 2022

通信作者简介:池振兴(1983—),男,博士,硕士生导师,主要研究方向为环境污染与健康。