慈菇对镉致大鼠脂质过氧化反应干预作用的探讨

为探讨慈菇对镉致大鼠脂质过氧化反应的干预作用,采用纯种Ｗｉｓｔａｒ 大鼠,随机分为６组：正常对照组、镉处理组、阳性对照组、低剂是干预组、中剂量干预组和高剂量干预组,连续观测６ 周。观察血清及肝匀浆脂质过氧化物（ＬＰＯ） 、肝匀浆谷胱甘肽过氧化物酶（ ＧＳＨｐｘ） 、血浆及肝组织镉（Ｃｄ）含量等指标。结果显示中剂量和高剂量干预组的血ＬＰＯ 均比镉处理组明显降低（Ｐ＜ ０－０５） ,而与阳性对照组无差别：３ 个剂量干预组肝组织Ｃｄ 含量均比镉处理组明显降低,高剂量组的肝组织Ｃｄ 与阳性对照组无差别;３ 个剂量干预组肝匀浆ＬＰＯ 与镉处理组及阳性对照组均无明显差别;高剂量干预组的ＧＳＨｐｘ 比镉处理组及阳性对照均明显增高。提示较高剂量的慈菇汁具有拮抗Ｃｄ 致大鼠脂质过氧化反应的作用。     

人参健脾丸中重金属及有害元素的测定、风险评估及最大限量理论值研究

目的 测定人参健脾丸（Renshen Jianpi Pills,RJP）中重金属及有害元素含量,对其进行风险评估并制定限度,为其安全使用提供指导。方法 采用电感耦合等离子体质谱法对收集到的30个厂家共135批RJP中的Pb、Cd、As、Hg和Cu5种重金属及有害元素进行测定;采用风险评估的方法对重金属和有害元素的安全性进行评估,计算危害指数（hazard index,HI）,并根据评估结果制定最大限量理论值。结果 有21批样品Pb元素和55批样品Hg元素的HI值>1,Cd、As和Cu元素HI值均<1。Pb和Hg元素的HI均值分别为0.85和5.32,远高于Cd、As和Cu元素的0.12、0.17和0.04,应予以关注。根据评估结果,结合RJP用法用量,制定Pb、Cd、As、Hg、Cu的最大限量理论值,大蜜丸和小蜜丸为0.5、0.5、1.0、0.1、135 mg/kg;水蜜丸为1.0、0.5、1.5、0.2、200 mg/kg。按制订的限度评价,分别有15批样品的Pb元素和70批样品的Hg元素超标,超标率分别为11.1%和51.9%。结论 所建立的风险评估法可有效评估RJP中...     

鱼腥草不同生长期各部位重金属镉、铅富集变化规律

目的采用ICP-MS测定鱼腥草不同生长期各部位重金属镉、铅富集量,分析其变化规律,为鱼腥草采收提供科学依据。方法收集5~10月鱼腥草生长期内各部位样品,采用微波消解-ICP-MS测定各部位重金属的含量。结果鱼腥草地下茎中镉、铅均在10月富集量最低;地上茎中镉在10月份富集量最低,7月份次之,其铅在7月富集量最低,10月次之;叶中镉在10月份富集量最低,7月份次之,其铅在7月富集量最低,10月次之。结论从安全性、有效性、产量综合考虑,建议7月(果期)、10月(倒苗前)作为鱼腥草药用部位最佳采收期,地下茎宜在10月割取地上部位后采收。     

微波消解-ICP-AES法测定太子参、粗叶悬钩子中Pb、Cd元素

目的：测定太子参和粗叶悬钩子中的Ph、Cd元素,并比较不同前处理方法的效果．方法：采用微波消解法进行样品的前处理,以电感耦合等离子体原子发射光谱法（ICP—AES）进行测定。结果：方法的回收率均在95％-105％之间,符合实验的可靠性要求,RSD〈3％。结论：微波消解法处理样品有相对的优越性,ICP—AES法测定样品中的重金属含量方法简便,快速省时,稳定性好。     

Ultrastructural distribution of synaptophysin and synaptic vesicle recycling at the frog neuromuscular junction

Synaptic vesicle recycling after intense acetylcholine (ACh) release was studied at the frog neuromuscular junction (NMJ) using the synaptic vesicle transmembrane protein synaptophysin as immunocytochemical marker of the synaptic vesicle membrane during the process of exo-endocytosis. ACh release in cutaneous pectoris nerve-muscle preparations was stimulated by three different means: K⁺, Cd²⁺ in Ca²⁺-free medium, and electrical stimulation in the presence of 4-aminopyridine (4-AP). Cd²⁺ stimulation produced synaptic vesicle depletion and nerve terminal swelling. Electrical stimulation in the presence of 4-AP produced a reduction in the number of synaptic vesicles, deep axolemmal infoldings, coated pits, and coated vesicles. K⁺ stimulation did not produce any observable ultrastructural changes. Synaptophysin was labeled using silver-intensified immunogold in dissociated muscle fibers. Unstimulated and K⁺-stimulated preparations showed synaptophysin immunolabeling associated only with synaptic vesicles. In contrast, in Cd²⁺-stimulated preparations, synaptophysin appeared along the axolemma, mainly at the active zones, and after electrical stimulation it appeared in both axolemmal infoldings and the remaining synaptic vesicles. The results show that when synaptic vesicle recycling is inhibited by Cd²⁺ in Ca²⁺-free medium, or when 4-AP is present during electrical stimulation, synaptic vesicle fusion is accompanied by translocation and incorporation of synaptic vesicle membrane proteins into the axolemma. However, during the latter condition, synaptic vesicles are recycled through coated vesicles arising from the axolemmal infoldings. Conversely, during physiological-like stimulation of ACh release by K⁺ the synaptic vesicles are rapidly recycled at the active zones, by a double and rapid process of exo-endocytosis, without collapse into the axolemma. © 1996 Wiley-Liss, Inc.     

ICP—MS法碰撞／反应池技术测定螺旋藻中砷、铅、镉含量的方法研究

目的建立螺旋藻中砷、铅、镉含量的八极杆碰撞／反应池电感耦合等离子体质谱（ORS—ICP—MS）测定方法。方法样品经HNO3＋H2O2微波消解体系消解后，用八级杆碰撞／反应池电感耦合等离子体质谱法同时测定砷、铅、镉含量。结果砷、铅、镉的检出限分别为0．01、0．02、0．003mg／kg；线性良好，线性相关系数均≥0．999；重现性好，变异系统RSD〈8％；准确度高，用国家一级标准参考物贻贝（GBW08571）、茶叶（GBW07605）标样质控，分析结果与标准值吻合。结论本法快速灵敏，精密度及准确度均符合要求，结果令人满意。     

镉致大鼠肾脏毒性机制研究

目的研究镉对肾脏产生的毒性作用,并初步探讨镉的肾脏毒性机制。方法低、中、高剂量染镉组大鼠分别皮下注射3,5,7μmol CdCl2/（kg·bw）6周。测定尿镉、蛋白含量和尿N-乙酰-β-D氨基葡萄糖苷酶（NAG）、碱性磷酸酶（ALP）、乳酸脱氢酶（LDH）活性,测定肝脏和肾皮质丙二醛（MDA）和谷胱甘肽（GSH）含量。结果尿蛋白含量和尿NAG、ALP、LDH活性以及肝、肾皮质MDA和GSH含量随染镉剂量增加而升高。中剂量染镉组尿蛋白含量和尿NAG、LDH活性以及肾皮质MDA、GSH含量显著高于对照组和低剂量染镉组。高剂量染镉组尿蛋白含量、ALP活性、肝和肾皮质MDA显著高于对照组和低中剂量染镉组。且尿镉、蛋白含量、尿NAG、ALP、LDH活性与肾皮质MDA含量呈显著正相关。结论镉生物学效应随染毒剂量增加而增强,CdCl2 5μmol/（kg·bw）对肾脏产生一定损伤作用,CdCl2 7μmol/（kg·bw）时肾脏损伤加重。镉的肾毒性机制与其氧化损伤作用有关。     

当归饮片及当归配方颗粒中铅镉砷汞残留量的测定

目的 建立测定当归饮片及当归配方颗粒中铅、镉、砷、汞残留量的方法.方法 采用聚四氟乙烯消化罐程序升温消解样品,以石墨炉原子吸收分光光度法测定铅、镉的含量;蒸气发生-原子荧光光谱法测定砷汞的含量.结果 铅、镉、砷、汞的回收率分别为107.3%、92.6%、90.2%、96.4%.结论 该法操作简便、快速,可用于中药材及成药中铅、镉、砷、汞残留量的测定.     

Investigations of the cytotoxicity of epigallocatechin-3-gallate against PC-3 cells in the presence of Cd in vitro

The epidemiological studies and recent data have provided convinced evidence that green tea and its major constituent epigallocatechin gallate (EGCG) might have the potential to lower the risk of cancers in humans. Metal ions, such as zinc and cadmium, which are necessary to our health, are important factors inducing many diseases including prostate cancer in the condition of absence or excess. EGCG can satisfactorily exhibit complex chemistry with metal ions because of multiple hydroxyl states, which in turn changes their bioactivities and metabolism pathways. This paper presents the results of an investigation of the cytotoxicity of EGCG against PC-3 prostate cancer cells in the presence and absence of Cd²⁺ in vitro. The results showed that both EGCG and Cd²⁺ suppressed viability and clonegenecity of PC-3 cells, and the suppression effect was enhanced when EGCG added with Cd²⁺. Although Cd²⁺ up-regulated the 67 kDa laminin receptor (67LR), which is a migration-associated protein, the cell migration ability was not significantly increased after each treatment. We also found that EGCG and Cd²⁺ directly interacted with mitochondrial, and the mixture of EGCG and Cd²⁺ (EGCG + Cd²⁺) significantly caused loss of the mitochondrial membrane potential, decrease of the ATP content and activation of caspase-9 compared with EGCG treated alone. Taken together, these findings suggest that Cd²⁺ enhanced the cytotoxicity of EGCG to PC-3 cells by up-regulating the 67LR and the mitochondria-mediated apoptosis pathway.     

多次沉积GFAAS测定浸泡水中微量Pb和Cd

〔目的〕提高GFAAS测定浸泡水中Pb和Cd的灵敏度 ,降低检出限。〔方法〕利用石墨炉自动进样器在石墨管中多次沉积。〔结果〕采用 5次沉积 ,使Pb和Cd的灵敏度分别提高 5 .17倍和 4 .86倍 ,检出限分别降低 4 .7倍和 4 .3倍 ,达到 0 .34ng/ml和 0 .0 37ng/ml。方法的精密度和回收率均符合测定要求。〔结论〕本法无需在前处理时进行富集 ,可直接分析浸泡水中的低含量铅和镉 ,方法具有简单、快速和准确的特点。