铅染毒对大鼠体内锌铜元素影响研究

[目的]研究铅染毒对大鼠体内锌铜元素的影响.[方法]将SD大鼠随机分为对照组和不同剂量醋酸铅染毒实验组,用醋酸铅饮用水染毒大鼠8周,在第8周末处死全部动物.取全血、血清、骨、脑组织,测定它们中的锌铜含量以及血铅、骨铅含量.[结果]随铅染毒剂量增加大鼠血铅和骨铅含量升高,组间差异均有统计学意义(P<0.05),血清、骨、脑中的锌含量下降,高剂量组与对照组差异均有统计学意义(P<0.05),骨铜含量下降,血铜和脑铜含量升高,高剂量组与对照组差异均有统计学意义(P<0.05).[结论]铅染毒对大鼠体内锌铜元素有明显影响.     

铅暴露对生长期大鼠回肠氮能神经元影响

目的 研究铅暴露对生长期大鼠回肠氮能神经元的影响,探讨铅致回肠氮能神经元形态改变或损伤的剂量-效应关系、时间-效应关系,为揭示铅中毒引起腹绞痛的毒理机制提供实验证据.方法 6周龄雄性SD大鼠75只,随机分为5组,每组15只,第1,2,3,4组为实验组,第5组为对照组.4个实验组动物分别用15,30,45,90mg/(kg·bw)的醋酸铅,采用灌胃方式染毒,每天1次;对照组以等量的双蒸水灌胃,每天1次.每组大鼠随机分为3小组,每小组以数字加以标注.在第10,30,90 d时对相对应小组大鼠进行血铅测定和回肠壁平铺冰冻块上切片后进行还原型辅酶A(β-NADPH)组织化学染色.结果 铅暴露生长期大鼠血铅浓度随染毒时间延长、染毒剂量的加大而升高;回肠-氧化氮合酶(NOS)阳性神经元数量、活性随染毒时间延长、染毒剂量的加大而降低;大鼠血铅浓度与回肠NOS阳性神经元数量存在负性相关,与NOS阳性神经元平均灰度值存在正性相关.结论 铅对回肠氮能神经元的影响不仅表现在铅暴露降低NOS活性,而且铅暴露致回肠氮能神经元的数量减少,且存在时间-效应、剂量-效应关系.     

实验性铅染毒对大鼠体内铜的影响

目的 :研究铅对铜的影响。方法 :以 0、0 5、2 0 g/L醋酸铅饮用水染毒大鼠 8周 ,在第 8周末处死全部动物 ,采取血、骨、脑、肾、卵巢及睾丸。测定样本中铜、血铅、骨铅含量。结果 :血铅和骨铅含量随铅染毒剂量增加而显著升高。铅染毒剂量最高时骨、肾中的铜含量显著降低 ,而脑中的铜含量显著升高     

长期饮用纯净水对大鼠脏器及组织铅蓄积的影响

目的观察长期饮用纯净水是否能增加铅在体内的蓄积及毒性。方法将104只断乳雄性SPF级SD大鼠随机分为8组(其中铅染毒组经饮水途径给予醋酸铅),分别为自来水对照组、纯净水对照组、低铅自来水组(含铅50mg/L)、低铅纯净水组(含铅50mg/L)、中铅自来水组(含铅200mg/L)、中铅纯净水组(含铅200mg/L)、高铅自来水组(800mg/L)、高铅纯净水组(含铅800mg/L)。各组食物及其他处理因素完全一致。于第4、6、8、10、24、28周尾静脉采全血动态监测血铅,在28周时处死大鼠取材,采用原子吸收分光-石墨炉法测定血铅及脑、心脏、肝脏、肾脏、骨等实质性脏器及组织的铅含量;以表面荧光法检测血液锌原卟啉(ZPP)含量。结果在相同的铅染毒剂量下,不同的饮水对大鼠血铅的影响未显示统计学意义,但饮用纯净水的大鼠肾脏、心脏、肝脏、脑、骨中的铅含量均高于饮用自来水的大鼠;同时饮用纯净水的大鼠其血液锌原卟啉含量均高于饮用自来水的大鼠,在低剂量铅染毒组间差异有统计学意义(P<0.05)。结论在本研究的染毒剂量下,结果提示长期饮用纯净水能增加铅在大鼠心、肝、肾、脑、骨中的蓄积及其对造血系统的毒性,尤其是在低铅暴露背景下。     

预防性排铅大鼠模型染毒剂量及其与血铅、尿铅时间效应关系

目的 研究不同剂量下染铅大鼠血铅、尿铅的时间变化效应，探讨通过腹腔注射染毒复制预防性排铅大鼠模型的适宜剂量。方法选用Wistar大鼠32只，随机分成4组：阴性对照组、低剂量组、中剂量组和高剂量组，分别给予腹腔注射乙酸铅溶液0．3ml／100g（剂量分别为每毫升溶液中含Pb^2＋0、11、546、1092μg），隔天注射1次，共7次。观察大鼠的中毒症状，每周末称体重，在染铅期间和停止染铅后定期检测大鼠血铅和尿铅含量。结果染铅1周后，3个剂量组血铅含量明显升高，中、高剂量组尿铅排出量迅速增加并达到高峰；停止染铅后，低剂量组血铅迅速降低，而中、高剂量组血铅仍处于较高的水中并持续到实验结束，尿铅排出量逐渐下降，到停铅5周时降到对照组的水平。结论过高剂量染铅使铅在体内蓄积，尿铅排出持续时间长，影响排铅制剂的排铅效果观察。建议以每毫升含546μgPb^2＋为染毒适宜剂量。     

染铅大鼠子代脑铅含量及对神经行为功能的影响

为探讨染铅大鼠子代脑铅含量及对神经行为功能的影响, 将Ｗｉｓｔａｒ 大鼠６０ 只随机分成高、中、低剂量和对照组, 进行醋酸铅饮水染毒实验。结果显示： 染毒各组大鼠子代脑铅含量均高于对照组, 呈随染毒剂量增加而增高的趋势。悬崖回避试验阳性率较对照组低且有显著差异（ Ｐ＜ ０－０１） ; 学习、记忆功能染毒各组均比对照组时间明显延长（ Ｐ＜ ０－０１） 。提示： 铅通过母体对子代造成脑铅的蓄积, 导致早期行为发育和学习记忆功能的损害。     

铅染毒对大鼠体内铜元素的影响研究

目的：探讨铅染毒后对铜元素的影响和意义。方法：将SD大白鼠随机分为对照组和不同剂量醋酸铅染毒实验组。用醋酸铅饮用水染毒大白鼠8周，在第8周末处死全部动物，取血、骨、脑、肾、卵巢及睾丸组织，测定组织中铜、血铅、骨铅含量。结果：血铅和骨铅含量随铅染毒剂量增加而升高，组间差异均有统计学意义（P〈0．05）。骨、肾组织中的铜含量降低，组间差异均有统计学意义（P〈0．05）。脑组织中的铜含量升高，组间差异均有统计学意义（P〈0．05）。结论：铅染毒对大鼠体内组织中铜的含量有影响。     

低铅染毒对大鼠脂质过氧化作用的影响

目的 探讨长期低铅染毒对大鼠内分泌脂质过氧化作用及超氧化歧化酶活性的影响。方法 将40只大鼠随机分成4组，分别给予含有不同剂量的铅饲料8周，测定并分析大鼠染毒后血中、甲状腺、胰腺组织中的铅含量、MDA、T-SOD、CAT、GSH-Px含量，并进行相关分析。结果 各组血铅随染铅剂量升高而升高；甲状腺、胰腺组织中的MDA含量随染铅剂量升高而升高，并与血铅浓度呈正相关；而甲状腺、胰腺组织中的T-SOD和GSH-Px含量随染铅剂量升高而下降，并与血铅浓度呈负相关；甲状腺、胰腺组织中的CAT与染铅剂量无关。结论 慢性铅中毒增强机体的脂质过氧化作用，降低机体抗氧化酶系活力，可能参与了体内某些内分泌功能和组织学的损害机制。     

铅接触指标之间的实验性相关分析

本文研究了铅接触在不同时间,有关铅接触评价指标之间的相关性特征,以及血铅与脏器组织铅含量之间的相关性。实验动物选用成年雌性恒河猴,分别以醋酸铅5、20mg/kg剂量染毒45天并于停毒后7.5个月处死动物。分析结果表明,δ-ALA、ZPP和FEP在染毒的前30天即与PbB达到最大相关,显然这三者对铅水平的早期改变反应敏感。股骨、甲状腺和肝脏是机体铅蓄积的重要器官组织。     

铅对小鼠睾丸组织脂质过氧化作用及杭白菊对其保护作用的研究

本文通过给雄性小鼠腹腔注射醋酸铅染毒,测定各不同染毒剂量组与空白对照及杭白菊灌胃组中血铅、血浆中VitC和小鼠睾丸组织中T—SOD、GSH—Px活力,MDA含量．以观察铅对小鼠睾丸组织脂质过氧化作用及杭白菊对其保护作用。结果表明：铅染毒组T—SOD活力和GSH—Px活力下降．其中T—SOD活力与铅含量呈负相关（r＝-0．6098,P＜0．01）;杭白菊灌胃组T—SOD和GSH—Px活力上升,与铅染毒组相比,差异显著（P＜0．05）,其中GSH—Px恢复到对照水平。杭白菊灌胃组较染毒组血铅含量下降,血浆中VitC含量上升,差异显著（P＜0．05）。     

职业铅接触者血铅、发铅、尿铅相关性的研究

本文通过对32名铅蓄电池制造工和36名排字工的血铅、发铅、尿铅的相关性研究,发现血铅/发铅(r=0.604),血铅/尿铅(r=0.548)均呈高度显著性相关(P<0.0005),故认为血铅是铅接触工人较好的健康监护指标。文章还进一步探讨了发铅作为铅接触者活体生物检测材料的应用前景。     

Evaluation of studies of the relationship between blood lead and air lead

Summary An evaluation of the major studies of the effects of airborne lead on blood lead levels of male and female adult and child populations is presented. Analysis of these studies shows that the blood lead-air lead slope for adults is approximately 1.0 for both men and women. This implies that an exposure to an additional 1 g Pb/m³ of air can result in an increase of approximately 1 g Pb/100 ml of blood. The precision of the slope for adults is rarely better than ±0.5 to ±0.7 and can be as large as ±1.0. A large portion of this uncertainty in the calculated slope is due to blood lead measurement error. The slope of the blood lead-air lead response for children ranges from 0.7 to 1.4 and is approximately the same as that for adults. The accuracy of this number is less clear for children than adults due to the small data base. Many of the studies of children have been on populations living in the vicinity of smelters. It is questioned whether these data are representative of the air lead exposure of children living in urban and suburban communities.     

铅作业工人血铅、尿铅和锌原卟啉测定结果分析

目的比较铅作业工人和非铅作业工人血铅、尿铅浓度、红细胞锌原卟啉和血常规的差异,探讨铅作业工人红细胞锌原卟啉和血铅、尿铅浓度的相关性。方法以蓄电池企业的252名铅作业工人作为接铅组,电子厂205名非铅作业工人作为对照组,测定血铅、尿铅浓度、红细胞锌原卟啉和血常规,并对结果进行统计学处理。结果接铅组血红蛋白含量低于对照组(P0.05),白细胞和红细胞、血小板则无差异(P0.05),接铅组红细胞锌原卟啉、血铅、尿铅浓度均显著高于对照组(P0.01),尿铅与红细胞锌原卟啉的相关系数(r)=0.166,血铅与红细胞锌原卟啉的相关系数r=0.406。结论长期接触铅可导致血铅、尿铅浓度和红细胞锌原卟啉升高,血红蛋白降低,对白细胞、红细胞、血小板无明显影响,血铅与红细胞锌原卟啉的相关性较尿铅与红细胞锌原卟啉的相关性好。     

Urinary lead as a possible surrogate of blood lead among workers occupationally exposed to lead

Objectives: The aim of the present study is to investigate whether lead (Pb) in urine (Pb-U) can be a valid surrogate of lead in blood (Pb-B), the traditional biomarker of exposure to lead in occupational health. Methods: Blood and spot urine samples were collected from 258 workers of both sexes occupationally exposed to lead. The samples were analyzed for lead by graphite furnace atomic absorption spectrometry, and the correlation between Pb-B and Pb-U was examined by linear regression analysis before and after logarithmic conversion. Results: The correlation coefficient (0.824; P < 0.01) was largest when the relationship between Pb-B and Pb-U was examined with 214 cases of one sex (i.e., men) after Pb-U was corrected for a specific gravity (1.016) of urine (Pb-Usg) and both Pb-B and Pb-Usg were converted to logarithms. The geometric means (GMs) of Pb-B and Pb-Usg for the 214 men were 489 μg/l and 81 μg/l, respectively. When Pb-Usg was assumed to be 100 μg/l in this set of correlations, the 95% confidence range of Pb-B for the group mean was narrow, i.e., 543–575 μg/l (with GM of 559 μg/l), whereas that for individual Pb-B values was as wide as 355–881 μg/l. Conclusions: The correlation of Pb-U with Pb-B among workers occupationally exposed to Pb was close enough to suggest that Pb-U may be a good alternative to Pb-B on a group basis, but not close enough to allow Pb-U to predict Pb-B on an individual basis. Received: 6 April 1999 / Accepted: 17 July 1999     

Impact of lead transport on children's blood and environmental lead levels

Introduction: A lead monitoring project was established in 1996 to monitor the environmental and health effects of lead being transported through a remote town in tarpaulin‐covered trucks. Methods: Dust samples from sites on the transport route were collected at 3–6 monthly intervals between 1996 and 1999. Annual blood lead testing clinics, offering voluntary testing to children, were conducted from 1997 to 1999. Results: Of the 55 dust samples analysed, only nine contained particles of lead concentrate and these were present at very low levels. During the project 167 children were tested. The geometic mean of blood lead levels in 1997, 1998 and 1999 were 4.5 μg/dL, 5.0 μg/dL and 5.1 μg/dL, respectively (all within the normal range). Residence on the transport route was not associated with higher lead levels (P > 0.05). Conclusions: Lead transport was not associated with any detectable environmental contamination or increase in children's blood lead levels.     

Partition of circulating lead between serum and red cells is different for internal and external sources of lead

Serum lead, whole blood lead, and lead in both tibia and calcaneus were measured in each of 49 active lead workers. Serum lead correlated more strongly with both in vivo bone lead measurements than did whole blood lead. The ratio of serum lead to whole blood lead varied from 0.8% to 2.5% and showed a positive correlation with tibia, and an even stronger correlation with calcaneus lead. This implies that lead released from bone (endogenous exposure) results in a higher proportion of whole blood lead being in serum than is the case for exogenous exposure. This observation needs to be confirmed, and the relationships amongst the parameters must be studied further, particularly in former or retired lead workers. If confirmed, since at least a portion of lead in serum is readily diffusible and thus toxicologically more immediately significant than lead bound to red cells, the health implications of endogenous exposure may have to be reassessed. © 1996 Wiley-Liss, Inc.     

儿童高铅血症及轻度铅中毒的药物干预

铅在人体内是一种具有多系统毒性的重金属元素,铅对儿童的损害更敏感。对于高铅血症及轻度铅中毒的防治尚缺乏公认显著有效的药物,但铅中毒对儿童的智力和身体发育都存在不利影响。近年来,临床使用一些维生素、金属硫蛋白、微量元素和中药等对儿童轻度铅中毒进行治疗,这些药物在减少铅在胃肠道的吸收、降低血铅水平、改善铅中毒症状方面发挥作用。     

食物中铅及营养素摄入对儿童血铅的影响

目的:探讨食物中铅摄入及营养素摄入对儿童血铅的影响.方法:随机选择263名儿童进行血铅测定和膳食调查,并用原子吸收分光光度法测定食物中的铅含量,了解儿童铅及营养素的摄入量.根据血铅值分为高血铅组(≥100μg/L)及低血铅组(＜100μg/L),对比两组食物中铅及营养素摄入量,采用Logistic回归分析各营养素摄入与血铅的相关性.结果:263名儿童血铅平均值为(80.84±42.79)μg/L,其中血铅值≥100μg/L的儿童有55名(20.91%).食物中铅摄入量范围为3.99～43.9μg/(kg·d),均高于暂定每周摄入量(PTWI),高血铅组儿童铅摄入量较高,但总能量、糖类、纤维素、视黄醇、维生素B1、维生素B2、镁、磷等摄入量相应较低.Logistic回归分析显示,糖类、视黄醇是降低儿童血铅的因素.结论:机体血铅增高可能与铅摄入量较多,总能量、纤维素、维生素B1、B2、镁、磷,尤其是糖类、视黄醇摄入量相应较低有关.     

A study of the relationship between ambient lead and blood lead among lead battery workers

 Objective: To examine the relationship between ambient lead levels and blood lead levels and to explore the modifiers of the relationship between ambient lead and blood lead. Method: A cross-sectional study was conducted in two lead battery factories. Blood lead level and ambient lead concentration were measured for each participant concurrently. A structured questionnaire was administered to collect sociodemographic characteristics and occupational history. Design: Biological and personal environmental measurements of 219 lead-exposed workers were analyzed by both simple and multiple linear regression. A regression model was selected for interpretation. Results: A high correlation (r=0.62) between ambient lead (PbA) and blood lead (PbB) was observed. In addition, numerous factors, including age, sex, alcohol consumption, personal hygiene practice and type of lead exposure, were also found to influence blood lead levels. Although PbB was highly correlated with PbA, blood lead level may not be effectively lowered by reducing ambient lead level. Based on the regression coefficients, improvement of hygienic practice was more effective at lowering PbB than reducing ambient lead level. Good hygienic practice may be the preferential way to reduce lead exposure in current conditions. Conclusion: Education of correct work practice may be more important than engineering control in the developing countries to lower blood lead levels in lead battery factories. Received: 28 May 1996/Accepted: 30 August 1996