• Login
    View Item 
    •   Home
    • Brock Theses
    • Newly Added Theses
    • View Item
    •   Home
    • Brock Theses
    • Newly Added Theses
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    All of BrockUCommunitiesPublication DateAuthorsTitlesSubjectsThis CollectionPublication DateAuthorsTitlesSubjectsProfilesView

    My Account

    LoginRegister

    Statistics

    Display statistics

    The influence of estrogen on skeletal muscle myosin regulatory light chain phosphorylation, post-tetanic potentiation, work, and power in C57BL/6 mice

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Thumbnail
    Name:
    Brock_Pellegrino_Andrea_2023.pdf
    Size:
    5.722Mb
    Format:
    PDF
    Download
    Author
    Pellegrino, Andrea
    Keyword
    Estradiol
    Potentiation
    Skeletal Muscle
    Myosin
    
    Metadata
    Show full item record
    URI
    http://hdl.handle.net/10464/17808
    Abstract
    Estrogen hormones are implicated in influencing skeletal muscle contractile function and specifically, the interactions between myosin and actin that facilitate contraction. Myosin regulatory light chain (RLC) phosphorylation (RLC-p) is highly associated with an increase in the percentage of myosin proteins strongly bound to actin during contractile activity. Myosin RLC-p is also highly associated with post-tetanic potentiation (PTP) i.e. the short-term increase in force observed following tetanic stimulation characteristic of fast-twitch skeletal muscle. The purpose of this study was to examine the influence of ovarian hormone deficiency and 17β-Estradiol (E2) replacement, on the PTP of concentric twitch force and myosin RLC-p of mouse fast twitch skeletal muscle. To this end, 4-month-old wildtype C57BL/6 mice were allocated to the ovariectomized (OVX), ovariectomized with E2 replacement (OVX+E), or sham-ovariectomized (SHAM) condition (n=8 mice). Extensor digitorum longus (EDL) muscles were surgically extracted and mounted for in vitro contractile experiments at 25° C involving the use of a brief potentiating stimulus (PS) to induce PTP. The PS, consisting of four equally spaced tetani (400Hz, 100ms) over 10.5s, significantly increased concentric twitch force and myosin RLC-p levels across condition groups. However, no significant differences in PTP, myosin RLC-p, or rates of force development and relaxation were observed between muscles of the OVX, OVX+E and SHAM conditions. A significant drop in relative tetanic force amongst the first and second tetanus within the PS was observed of muscles from OVX mice compared to that of OVX+E and SHAM mice. Specific force, calculated as the ratio of force to muscle PCSA, total work, peak work, and power production, were significantly increased following the PS across conditions, and were significantly less of muscles from OVX mice compared to OVX+E and SHAM, both prior to and following the PS. Data are contrary to the primary hypothesis that E2 influences myosin RLC-p and PTP in fast twitch skeletal muscle, though are suggestive of an influence of OVX and E2 on skeletal muscle quality.
    Collections
    Newly Added Theses

    entitlement

     
    DSpace software (copyright © 2002 - 2023)  DuraSpace
    Quick Guide | Contact Us
    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.