• Login
    View Item 
    •   Home
    • UA Graduate and Undergraduate Research
    • UA Theses and Dissertations
    • Dissertations
    • View Item
    •   Home
    • UA Graduate and Undergraduate Research
    • UA Theses and Dissertations
    • Dissertations
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    All of UA Campus RepositoryCommunitiesTitleAuthorsIssue DateSubmit DateSubjectsPublisherJournalThis CollectionTitleAuthorsIssue DateSubmit DateSubjectsPublisherJournal

    My Account

    LoginRegister

    About

    AboutUA Faculty PublicationsUA DissertationsUA Master's ThesesUA Honors ThesesUA PressUA YearbooksUA CatalogsUA Libraries

    Statistics

    Most Popular ItemsStatistics by CountryMost Popular Authors

    Absorption and distribution of epidermal growth factor in the gastrointestinal tract of suckling rats.

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Thumbnail
    Name:
    azu_td_9322761_sip1_w.pdf
    Size:
    4.591Mb
    Format:
    PDF
    Download
    Author
    Kong, Wuyi.
    Issue Date
    1993
    Keywords
    Dissertations, Academic.
    Physiology.
    Committee Chair
    Koldovsky, Otakar
    
    Metadata
    Show full item record
    Publisher
    The University of Arizona.
    Rights
    Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
    Abstract
    Suckling rats show a low level of synthesis of epidermal growth factor (EGF) and obtain this important polypeptide from maternal milk. Thus, this study was performed to characterize how and where in the gastrointestinal tract the absorption of rat-EGF (rEGF) occurs and to which organs it is delivered. Although radiolabeled EGF transferred to the liver by the ileum was significantly higher than that by the jejunum, the total amounts of immunoreactive and receptor-binding active ¹²⁵I-rEGF in the liver were significantly higher from jejunal than from ileal absorption. These results indicate that the ileum degrades most of the ¹²⁵I-rEGF during absorption, whereas the jejunum absorbs more intact ¹²⁵I-rEGF. Higher numbers of EGF receptors were found in the brush border membranes of jejunum than that of the ileum, suggesting that the larger amounts of intact EGF delivered by the jejunum to the liver may be due to a higher capacity of EGF receptors in the jejunum. Liver and intestine were the main organs taking up the radioactivity after intrafemoral vein ¹²⁵I-rEGF administration. The degradation rates of EGF in the liver, intestine and pancreas were significantly lower in suckling as opposed to adult rats. In suckling rats intact rEGF was secreted by the liver into the bile and by the enterocytes into the lumen of the intestine. The competitive effects of unlabeled rEGF were found at both sides of the small intestine and at the circulatory side of the liver, submandibular glands, pancreas, and other organs, indicating a receptor-related uptake of EGF from the lumen and circulation of these organs in suckling rats. The results indicate that after absorption maternal milk-EGF stays mainly in the digestive system during the suckling period. The amount of EGF in each organ may remain relatively stable on a daily basis since EGF is absorbed continuously from the jejunum in suckling rats and is distributed and circulated in the digestive system by hepatico-enteric, entero-enteric, and perhaps pancreatico-enteric circulations; in this way, EGF accelerates the growth of the digestive system.
    Type
    text
    Dissertation-Reproduction (electronic)
    Degree Name
    Ph.D.
    Degree Level
    doctoral
    Degree Program
    Physiology
    Graduate College
    Degree Grantor
    University of Arizona
    Collections
    Dissertations

    entitlement

     
    The University of Arizona Libraries | 1510 E. University Blvd. | Tucson, AZ 85721-0055
    Tel 520-621-6442 | repository@u.library.arizona.edu
    DSpace software copyright © 2002-2017  DuraSpace
    Quick Guide | Contact Us | Send Feedback
    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.