• 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

    THE EFFECTS OF BETA-ADRENERGIC BLOCKADE ON EXERCISE CAPACITY AND THERMOREGULATION IN TRAINED AND UNTRAINED SUBJECTS.

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Thumbnail
    Name:
    azu_td_8522810_sip1_c.pdf
    Size:
    3.999Mb
    Format:
    PDF
    Download
    Author
    FREUND, BEAU JEFFERE.
    Issue Date
    1985
    Keywords
    Adrenergic beta blockers.
    Exercise -- Physiological aspects.
    
    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
    Two investigations were conducted to examine the influence of beta-adrenergic blockade on cardiovascular, respiratory, metabolic, and thermoregulatory responses to maximal and submaximal exercise in both highly trained and untrained subjects. In both studies, subjects received randomized and double-blind oral medication with atenolol (100 mg/day), propranolol (160 mg/day), and placebo. In the first study significant reductions in HR max and ‘VO₂ max resulted during the atenolol and propranolol treatments in both the trained and untrained subjects. However, the reductions in ‘VO₂ max were significantly greater in the trained subjects and both groups experienced their greatest reduction during the propranolol treatment. In all subjects, the magnitude of reduction in HR max was significantly greater than the concomitant decrease in ‘VO₂ max. It is concluded that untrained subjects have a greater compensatory reserve than do trained subjects during maximal exercise while under beta-adrenergic blockade. In addition, significant advantages were found with the use of a selective compared to a non-selective beta blocker. Thermoregulation during prolonged exercise in the heat with beta blockade was studied in fourteen subjects. Subjects performed 90-minute cycle ergometer rides at a workload equivalent to 40% of the subjects' unblocked ‘VO₂ max. Rectal temperature was slightly higher during the atenolol trial compared to the placebo but was not different during the propranolol trial compared to the placebo. Skin blood flow was significantly lower during the propranolol trial compared to both the atenolol and placebo trials, but it did not differ significantly between the atenolol and placebo trials. Maintenance of rectal temperatures appeared to be achieved through changes in sweat rate, skin blood flow, and a reduced heat production, i.e., lower ‘VO₂ during the propranolol trial. The decrease in cutaneous blood flow reported during the propranolol trial is likely associated with the associated increase in TPR. This increase in TPR would help to compensate for the lower ‘Q and, hence, help maintain mean arterial pressure. Changes in substrate utilization, i.e., decreased lipolysis, during the beta-blocked trials may also be indicated. Lastly, the inability of two subjects to complete the 90-minute ride, the elevated RPE values, and the additional side effects reported during the propranolol trial would indicate an advantage for the use of a selective blocker.
    Type
    text
    Dissertation-Reproduction (electronic)
    Degree Name
    Ph.D.
    Degree Level
    doctoral
    Degree Program
    Animal 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.