Am J Physiol Cell Physiol AJP: Heart and Circulatory Physiology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Cell Physiol 258: C92-C98, 1990;
0363-6143/90 $5.00
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
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 Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Mackenzie, L. W.
Right arrow Articles by Stull, J. T.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Mackenzie, L. W.
Right arrow Articles by Stull, J. T.

AJP - Cell Physiology, Vol 258, Issue 1 C92-C98, Copyright © 1990 by American Physiological Society

ARTICLES

Myosin light chain phosphorylation in human myometrial smooth muscle cells

L. W. Mackenzie, R. A. Word, M. L. Casey and J. T. Stull
Cecil H. and Ida Green Center for Reproductive Biology Sciences, University of Texas, Southwestern Medical Center, Dallas 75235.

Ca2+/calmodulin-dependent phosphorylation of the 20-kDa regulatory light chain of myosin is of signal importance in the initiation of contraction in a number of smooth muscle tissues. In this investigation, we evaluated the relationship between intracellular free Ca2+/concentration [( Ca2+]i) and the extent of myosin light chain phosphorylation in cultured human myometrial smooth muscle cells. Treatment of myometrial cells with ionomycin caused a concentration- and time-dependent increase in [Ca2+]i and phosphorylation of myosin light chain. Temporally, the increases in light chain phosphorylation and [Ca2+]i in response to ionomycin were similar. In myometrial cells treated with ionomycin (10(-5) M) for 10 s, [Ca2+]i increased from 138 to 800 nM; in these same cells, myosin light chain phosphorylation increased from 5% to a maximum value of 54%. Half-maximal phosphorylation of myosin light chain was attained at 300 nM [Ca2+]i. Treatment of myometrial smooth muscle cells with prostaglandin (PG) F2 alpha (10(-8) M) and PGE2 (10(-8) M) caused a proportionate increase in [Ca2+]i and myosin light chain phosphorylation. In addition, [Ca2+]i and myosin light chain phosphorylation increased in response to oxytocin and angiotensin II. These findings indicate that a number of uterotonic agents effect an increase in [Ca2+]i, which in turn causes phosphorylation of myosin light chain. Furthermore, the concentration of Ca2+ in the cytoplasm is a primary determinant for myosin light chain phosphorylation in human myometrial smooth muscle cells.


This article has been cited by other articles:


Home page
 Am. J. Physiol. Cell Physiol.Home page
L. Bursztyn, O. Eytan, A. J. Jaffa, and D. Elad
Mathematical model of excitation-contraction in a uterine smooth muscle cell
Am J Physiol Cell Physiol, May 1, 2007; 292(5): C1816 - C1829.
[Abstract] [Full Text] [PDF]

Home page
 J. Pharmacol. Exp. Ther.Home page
M. Trujillo, L. Candenas, C. G. Cintado, J. Magraner, J. Fernandez, J. D. Martín, and F. M. Pinto
Hormonal Regulation of the Contractile Response Induced by Okadaic Acid in the Rat Uterus
J. Pharmacol. Exp. Ther., March 1, 2001; 296(3): 841 - 848.
[Abstract] [Full Text]

Home page
 Am. J. Physiol. Cell Physiol.Home page
V. P. Fomin, B. E. Cox, and R. A. Word
Effect of progesterone on intracellular Ca2+ homeostasis in human myometrial smooth muscle cells
Am J Physiol Cell Physiol, February 1, 1999; 276(2): C379 - C385.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online