Journal of the Society for Gynecologic Investigation

 

Advanced Search

Journal Navigation

Journal Home

Subscriptions

Archive

Contact Us

Table of Contents

Register here to gain access to SAGE's 500+ Journals Online

Click here to sign up for SAGE Journal Email Alerts today!

Sign In to gain access to subscriptions and/or personal tools.
This Article
Right arrow Full Text (PDF)
Right arrow References
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to Saved Citations
Right arrow Download to citation manager
Right arrowRequest Permissions
Right arrow Request Reprints
Right arrow Add to My Marked Citations
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Matthew, A.
Right arrow Articles by Wray, S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Matthew, A.
Right arrow Articles by Kupittayanant, S.
Right arrow Articles by Burdyga, T.
Right arrow Articles by Wray, S.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati  
What's this?
Journal of the Society for Gynecologic Investigation, Vol. 11, No. 4, 207-212 (2004)
DOI: 10.1016/j.jsgi.2003.10.009

Characterization of Contractile Activity and Intracellular Ca2+ Signalling in Mouse Myometrium

A. Matthew, BSc

S. Kupittayanant, PhD

T. Burdyga, DSc

Department of Physiology, The University of Liverpool, Liverpool, United Kingdom; Department of Physiology, Suranaree University of Technoclogy, Thailand

S. Wray, PhD

Department of Physiology, Suranaree University of Technoclogy, Thailand; Department of Physiology, The University of Liverpool, Liverpool L69 3BX, United Kingdom. s.wray{at}liv.ac.uk

Objective: To characterize the contractile responses of mouse myometrium, the associated calcium (Ca2+) changes and the role of the sarcoplasmic reticulum (SR), and to better understand excitation contraction coupling in this tissue.

Methods: Strips of longitudinal myometrium were used, and Ca2+ was measured after loading with Indo-1.

Results: Intracellular Ca2+ transients, produced by Ca2+ entry, preceded phasic spontaneous contractions. Depolarization with high potassium concentration significantly increased the amplitude of the contractions and transformed the pattern of activity from phasic to tonic, with accompanying changes in intracellular Ca2+ concentration ([Ca2+]i). Oxytocin significantly stimulated contractile activity and [Ca2+]i above the level occurring spontanouesly. Thus all forms of contractile activity were closely correlated with Ca2+. When the SR was emptied using a blocker of the SR calcium-adenosinetriphosphatase, cyclopiazonic acid, spontaneous Ca2+ and force transients increased greatly in frequency and amplitude. Ryanodine, a blocket of Ca2+ -induced Ca2+ release (CICR), did not impair activity. In the absence of external Ca2+, oxytocin was able to relase Ca2+ from the SR through IB3 but produced only a small increase in force, demonstrating a requirement for Ca2+ entry as part of the mechanism of agonist action.

Conclusion: Mouse myometrium, (1) produces contractile activity reflecting changes in [Ca2+]i irrespective of the stimulus, (2) has a significant SR Ca2+ content releasable by agonist by not CICR, (3) has an SR acting to inhibit spontaneous activity, and (4) behaves qualitatively similarly to human and rat myometrium in major aspects of excitation contraction coupling and is therefore a useufl model tissue.

Key Words: Smooth muscle • SR Ca2+ release • agonists • sarcoplasmic reticulum


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati    What's this?