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dc.creatorTang, Yan
dc.date.accessioned2012-06-07T22:57:48Z
dc.date.available2012-06-07T22:57:48Z
dc.date.created1999
dc.date.issued1999
dc.identifier.urihttps://hdl.handle.net/1969.1/ETD-TAMU-1999-THESIS-T35
dc.descriptionDue to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to digital@library.tamu.edu, referencing the URI of the item.en
dc.descriptionIncludes bibliographical references (leaves 54-63).en
dc.descriptionIssued also on microfiche from Lange Micrographics.en
dc.description.abstractPolycyclic aromatic hydrocarbons (PAHs) and halogenated aromatic hydrocarbons (HAHs) are ubiquitous in the environment. Some congeners produce extreme toxicity in laboratory Animal studies. While much attention has been given to the carcinogenicity, little work has been done in neurotoxicology. Therefore, the focus of this thesis was to analyze neurotoxicity by these measurements of cytotoxicity in neuronal and goal 11 lines. Amino acid incorporation into proteins, total protein, trypan blue dye exclusion and total cell count were measured as indicators of cytotoxicity. In addition acetycholinesterase (ACM) activity was measured as a direct indicator of neurotoxicity. Cells were exposed to three model PAHs, benzo(a)pyrene (BAP), cosine, and anthracene, and one model HAH, pentachlorophenol (PCP). Neurotoxicity of individual PAHs and PCP was compared with mixtures of PAHs and PCP. In this thesis SY5Y and C6 cell lines were used. The test concentrations of each PAH and PCP were 0.03, 0.3, 3. 30 []M. BAP showed the highest mycotoxic of the compounds tested. At a dose of 3 []M or 30 []M, BAP produced a significant mycotoxic response in SY5Y cells. SY5Y cells teated with cosine, anthracene, and PCP showed no significant effects compared to controls. C6 cells appeared to be less sensitive to the cytotoxicity then SY5Y cells. This finding may reject the lower level of P450 activity compared with SY5Y cells. S9 liver extras, which possesses high P450 activity, was used to enhance metabolism of PAHs. In most cases, the individual PAHs were inactive in C6 cells without agitation, while cytotoxicity was increased following S9 metabolism. In the present study, the rank order of neurotoxicity was BAP > chrysene > anthracene. In SY5Y cells, mixtures of BAP and chrysene or BAP and PCP exhibited the same degree of cytotoxicity as did the individual chemicals. However, in C6 cells the mixture of 3 []M BAP and 3 []M chrysene induced a more mycotoxic response than at same concentration of individual compounds. PCP at 3[]M alone significantly inhibited AChE activity in SY5Y cells, but BAP and chrysene had no effect. Furthermore, binary mixtures of PCP with mipafox together produced a significant increase in inhibition of AChE. These data suggest that co- exposure to PCP and organophosphates may result in a chemical interaction that increases the relative toxic response.en
dc.format.mediumelectronicen
dc.format.mimetypeapplication/pdf
dc.language.isoen_US
dc.publisherTexas A&M University
dc.rightsThis thesis was part of a retrospective digitization project authorized by the Texas A&M University Libraries in 2008. Copyright remains vested with the author(s). It is the user's responsibility to secure permission from the copyright holder(s) for re-use of the work beyond the provision of Fair Use.en
dc.subjectveterinary anatomy.en
dc.subjectMajor veterinary anatomy.en
dc.titleDevelopment of in vitro screening assays for potentially neurotoxic polyaromatic hydrocarbons in SY5Y and C6 cellsen
dc.typeThesisen
thesis.degree.disciplineveterinary anatomyen
thesis.degree.nameM.S.en
thesis.degree.levelMastersen
dc.type.genrethesisen
dc.type.materialtexten
dc.format.digitalOriginreformatted digitalen


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