• Login
    View Item 
    •   UMB Digital Archive
    • School, Graduate
    • Theses and Dissertations All Schools
    • View Item
    •   UMB Digital Archive
    • School, Graduate
    • Theses and Dissertations All Schools
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    All of UMB Digital ArchiveCommunitiesPublication DateAuthorsTitlesSubjectsThis CollectionPublication DateAuthorsTitlesSubjects

    My Account

    LoginRegister

    Statistics

    Display statistics

    Effects of polychlorinated biphenyls (PCBs) on reproduction, physiological processes, and biomarkers in tree swallows (Tachycineta bicolor)

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Find Full text
    Author
    Yorks, Amy Lynn
    Advisor
    Squibb, Katherine S.
    Melancon, Mark
    Date
    1999
    Type
    dissertation
    
    Metadata
    Show full item record
    Abstract
    Tree swallow (Tachycineta bicolor) nestlings were studied at ten sites exhibiting a range of polychlorinated biphenyl (PCB) contamination. Nesting success, offspring survival, and growth and developmental parameters were recorded. In addition to determining PCB concentrations in eggs, twelve-day-old nestlings, and food items, hepatic cytochromes P450-associated monooxygenase activities (BROD and EROD) were quantified as a biomarker of exposure. Eggs and nestlings from one site were dosed with model cytochromes P450 inducers, beta-naphthoflavone (BNF), 3-methylcholanthrene, PCB 126, and various Aroclors. A subset of microsomal samples was examined by protein immunoblotting. Heart and skin samples from nestlings were examined immunohistochemically to determine relative amounts and cellular location of CYPIA. Effects on gender and gonadal development of nestling offspring were assessed. A range of PCB contamination was seen in composite sediment (0.02-16ppm) and egg (0.7-9.7ppm) samples from the field sites. While there were only subtle differences between reproductive and growth parameters from nestlings at various sites, body burdens of PCBs were significantly different and correlated strongly with PCB levels in sediment, eggs, and food sources. PCBs were deposited in Tree swallow eggs and accumulated in nestlings. There was no evidence of abnormal gonadal development or anatomical gender alteration due to PCB exposure in nestling Tree swallows. Although BNF induced cytochromes P450 as assessed by enzyme activity and protein immunoblotting, PCBs were ineffective inducers except in the case of pipped embryos which were treated in ovo with PCB 126 and exhibited dose-related enzyme induction. BROD and EROD activities correlated significantly with each other (r > 0.8). Differences between sites and treatments show that there is a cytochrome P450 biomarker response in Tree swallows which is indicative of contaminant exposure and effects. Tree swallows appear to be resistant to the reproductive and physiological effects of PCBs and cytochrome P450 induction at field sites may be due to parallel contaminants. Due to their resilience to PCB contamination, Tree swallows did not prove to be a good sentinel species. However, Tree swallows are good indicators of PCB exposure through chemical analyses of tissues.
    Description
    University of Maryland, Baltimore. Toxicology. Ph.D. 1999
    Keyword
    Biology, Ecology
    Health Sciences, Toxicology
    Environmental Sciences
    Environmental monitoring
    Indicators (Biology)
    Tree swallow
    Polychlorinated Biphenyls
    Identifier to cite or link to this item
    http://hdl.handle.net/10713/1326
    Collections
    Theses and Dissertations All Schools
    Theses and Dissertations School of Medicine

    entitlement

     
    DSpace software (copyright © 2002 - 2023)  DuraSpace
    Quick Guide | Policies | Contact Us | UMB Health Sciences & Human Services Library
    Open Repository is a service operated by 
    Atmire NV
     

    Export search results

    The export option will allow you to export the current search results of the entered query to a file. Different formats are available for download. To export the items, click on the button corresponding with the preferred download format.

    By default, clicking on the export buttons will result in a download of the allowed maximum amount of items.

    To select a subset of the search results, click "Selective Export" button and make a selection of the items you want to export. The amount of items that can be exported at once is similarly restricted as the full export.

    After making a selection, click one of the export format buttons. The amount of items that will be exported is indicated in the bubble next to export format.