AJP - Heart Watch the video to learn how APS reaches out to developing nations.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
QUICK SEARCH:   [advanced]


     

Am J Physiol Heart Circ Physiol (September 9, 2004). doi:10.1152/ajpheart.00655.2004
This Article
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
288/1/H142    most recent
00655.2004v1
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 Web of Science
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 Web of Science (9)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Xiao, D.
Right arrow Articles by Zhang, L.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Xiao, D.
Right arrow Articles by Zhang, L.
Submitted on July 2, 2004
Accepted on August 18, 2004

Adaptation of Uterine Artery Thick and Thin Filament Regulatory Pathways to Pregnancy

DaLiao Xiao1 and Lubo Zhang1*

1 Center for Perinatal Biology, Department of Physiology & Pharmacology, Loma Linda University School of Medicine, Loma Linda, CA, USA

* To whom correspondence should be addressed. E-mail: lzhang{at}som.llu.edu.

Little is known about the adaptation of contractile mechanisms of uterine artery smooth muscle to pregnancy. The present study tested the hypothesis that pregnancy differentially regulates thick and thin filament regulatory pathways in the uterine artery. Isometric tension, intracellular free Ca2+ concentration ([Ca2+]i), and phosphorylation of 20 kDa myosin light chain (MLC20) were measured simultaneously in uterine arteries isolated from nonpregnant and near-term (140 days gestation) pregnant sheep. Phenylephrine-mediated [Ca2+]i, MLC20 phosphorylation and contractions were significantly increased in pregnant, as compared with nonpregnant, uterine arteries. In contrast, phenylephrine-mediated Ca2+ sensitivity of MLC20 phosphorylation was decreased in the pregnant uterine arteries. Simultaneous measurement of phenylephrine-stimulated tension and MLC20 phosphorylation in the same tissue indicated a decrease in MLC20 phosphorylation-independent contractions in the pregnant uterine arteries. In addition, activation of protein kinase C (PKC) produced significantly lower sustained contractions in pregnant, as compared with nonpregnant, uterine arteries in the absence of changes in MLC20 phosphorylation levels in either vessel. In the nonpregnant uterine arteries, the MEK/ERK inhibitor PD098059 significantly increased phenylephrine-mediated, MLC20 phosphorylation-independent contractions. The results suggest that in the uterine artery pregnancy up-regulates {alpha}1-adrenoceptor-mediated Ca2+ mobilization and MLC20 phosphorylation. In contrast, pregnancy down-regulates the Ca2+ sensitivity of myofilaments, which is mediated by both thick and thin filament pathways.




This article has been cited by other articles:


Home page
 HypertensionHome page
D. Xiao, X. Huang, S. Yang, and L. Zhang
Direct Chronic Effect of Steroid Hormones in Attenuating Uterine Arterial Myogenic Tone: Role of Protein Kinase C/Extracellular Signal-Regulated Kinase 1/2
Hypertension, August 1, 2009; 54(2): 352 - 358.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
K. Chang, D. Xiao, X. Huang, L. D. Longo, and L. Zhang
Chronic hypoxia increases pressure-dependent myogenic tone of the uterine artery in pregnant sheep: role of ERK/PKC pathway
Am J Physiol Heart Circ Physiol, June 1, 2009; 296(6): H1840 - H1849.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Regul. Integr. Comp. Physiol.Home page
W. Chen and R. A. Khalil
Differential [Ca2+]i signaling of vasoconstriction in mesenteric microvessels of normal and reduced uterine perfusion pregnant rats
Am J Physiol Regulatory Integrative Comp Physiol, December 1, 2008; 295(6): R1962 - R1972.
[Abstract] [Full Text] [PDF]

Home page
 Reproductive SciencesHome page
K. Chang and Lubo Zhang
Review Article: Steroid Hormones and Uterine Vascular Adaptation to Pregnancy
Reproductive Sciences, April 1, 2008; 15(4): 336 - 348.
[Abstract] [PDF]

Home page
 Biol. Reprod.Home page
H. Zhang and L. Zhang
Role of Protein Kinase C Isozymes in the Regulation of alpha1-Adrenergic Receptor-Mediated Contractions in Ovine Uterine Arteries
Biol Reprod, January 1, 2008; 78(1): 35 - 42.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
H. Zhang, D. Xiao, L. D. Longo, and L. Zhang
Regulation of {alpha}1-adrenoceptor-mediated contractions of uterine arteries by PKC: effect of pregnancy
Am J Physiol Heart Circ Physiol, November 1, 2006; 291(5): H2282 - H2289.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
D. Xiao, X. Huang, L. D. Longo, W. J. Pearce, and L. Zhang
Regulation of baseline Ca2+ sensitivity in permeabilized uterine arteries: effect of pregnancy
Am J Physiol Heart Circ Physiol, July 1, 2006; 291(1): H413 - H420.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
D. Xiao, J. N. Buchholz, and L. Zhang
Pregnancy attenuates uterine artery pressure-dependent vascular tone: role of PKC/ERK pathway
Am J Physiol Heart Circ Physiol, June 1, 2006; 290(6): H2337 - H2343.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
Visit Other APS Journals Online
Copyright © 1977 by the American Physiological Society.