Molecular toxicology最新文献_第3页

Analysis of proteins cross-linked to DNA after treatment of cells with formaldehyde, chromate, and cis-diamminedichloroplatinum(II). 用甲醛、铬酸盐和顺式二胺二氯铂处理细胞后与DNA交联的蛋白质分析(II)。

Molecular toxicology Pub Date : 1989-01-01

C A Miller, M Costa

引用次数: 0

Plasma membrane damage detected by nucleic acid leakage. 核酸渗漏检测质膜损伤。

Molecular toxicology Pub Date : 1989-01-01

E Fortunati, V Bianchi

{"title":"Plasma membrane damage detected by nucleic acid leakage.","authors":"E Fortunati, V Bianchi","doi":"","DOIUrl":"","url":null,"abstract":"Among the indicators of membrane damage, the leakage of intracellular components into the medium is the most directly related to the perturbations of the membrane molecular organization. The extent of the damage can be evaluated from the size of the released components. We have designed a protocol for the detection of membrane leakage based on the preincubation of cells with tritiated adenine for 24 h, followed by a 24-h chase in nonradioactive medium. The treatment takes place when the distribution of the precursor among its end products has reached the plateau, and thus the differences of radioactivity in the fractions obtained from the control and treated cultures (medium, nucleotide pool, RNA, DNA) correspond to actual quantitative variations induced by the test chemical. Aliquots of the medium are processed to determine which percentage of the released material is macromolecular, in order to distinguish between mild and severe membrane damage. The origin of the extracellular radioactivity can be recognized from the variations of RNA counts in the treated cells. DNA radioactivity is used to evaluate the number of cells that remain attached to the plates in the different conditions of treatment. By this means, generalized permeabilization of membranes to macromolecules is distinguished from complete solubilization of only a subpopulation of cells. We present some examples of application of the protocol with detergents (LAS, SDS, Triton X-100) and with Cr(VI), which damages cell membranes by a different mechanism of action.","PeriodicalId":77750,"journal":{"name":"Molecular toxicology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1989-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13626554","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

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Polybrominated naphthalene and diiodobenzene interactions with specific binding sites for 2,3,7,8-tetrachlorodibenzo-p-dioxin in rat liver cytosol. 多溴萘和二碘苯与大鼠肝细胞质中2,3,7,8-四氯二苯并对二恶英特异性结合位点的相互作用

Molecular toxicology Pub Date : 1989-01-01

E N Cheung, J D McKinney

{"title":"Polybrominated naphthalene and diiodobenzene interactions with specific binding sites for 2,3,7,8-tetrachlorodibenzo-p-dioxin in rat liver cytosol.","authors":"E N Cheung, J D McKinney","doi":"","DOIUrl":"","url":null,"abstract":"We provide evidence for two new classes of halogenated aromatic hydrocarbon ligands for the 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD or Ah) receptor: brominated naphthalenes and iodobenzenes. Polybrominated naphthalenes with four or more bromine atoms concentrated in lateral positions were shown to bind specifically and with high affinity (Kd approximately 10(-8) M) to the Ah receptor in rat liver cytosol preparations. The hexabrominated naphthalene isomers bind with high and nearly equal affinities but have been previously shown to have different toxicological properties. Possible explanations for these differences include differences in metabolism, antagonist versus agonist Ah receptor binding of some isomers, and the involvement of other binding sites in vivo that require different structural requirements. The moderate binding activity of the diiodobenzenes suggests that thyroid hormones should receive further study as possible endogenous ligands for the Ah receptor. It is difficult to explain the binding results with these two classes of compounds using previously developed molecular concepts for Ah receptor interactions based primarily on molecular size considerations.","PeriodicalId":77750,"journal":{"name":"Molecular toxicology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1989-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13703450","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Do we find relevant parameters for in vitro cytotoxicity testing? 我们是否找到了体外细胞毒性试验的相关参数?