| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Division of Pharmaceutical Sciences, University of Wyoming College of Health Sciences, Laramie, Wyoming 82071-3375; 2 University of North Dakota School of Medicine, Grand Forks 58203; 3 United States Department of Agriculture, Grand Forks Human Nutrition Research Center, Agricultural Research Service, Grand Forks 58202; and 4 Center for Biomedical Research, University of North Dakota School of Medicine, Grand Forks, North Dakota 58203
Women with functional
ovaries have a lower cardiovascular risk than men and postmenopausal
women. However, estrogen replacement therapy remains controversial.
This study examined the effect of ovarian hormone deficiency and
estrogen replacement on ventricular myocyte contractile function and
PKB/Akt activation. Nulliparous female rats were subjected to bilateral
ovariectomy (Ovx) or sham operation (sham). A subgroup of Ovx rats
received estrogen (E2) replacement (40 µg · kg
1 · day1)
for 8 weeks. Mechanical and intracellular Ca2+ properties
were evaluated including peak shortening (PS), time to PS (TPS), time
to 90% relengthening (TR90), maximal velocity of
shortening/relengthening (±dL/dt), fura 2 fluorescence intensity (FFI), and decay rate. Levels of
sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA2a),
phospholamban (PLB), and Akt were assessed by Western blot. Ovx
promoted body weight gain associated with reduced serum E2
and uterine weight, all of which were abolished by E2. Ovx
depressed PS and ±dL/dt, prolonged TPS,
TR90, and decay rate, and enhanced resting FFI, all of
which, with the exception of TPS, were restored by E2. Ovx
did not alter the levels of SERCA2a, PLB, and total Akt, but
significantly reduced Akt activation [phosphorylated Akt (pAkt)],
pAkt/Akt, and the SERCA2a-to-PLB ratio. These alterations in protein
expression were restored by E2. E2 enhanced PS
and +dL/dt in vitro, which was abolished by the
E2 receptor antagonist ICI-182780. Ovx reduced myocyte
Ca2+ responsiveness and lessened stimulating
frequency-induced decline in PS, both ablated by E2. These
data suggest that mechanical and protein functions of ventricular
myocytes are directly regulated by E2.
ovariectomy; cardiac myocyte; contraction, intracellular Ca2+
This article has been cited by other articles:
|
|
 |
|
  T. Bupha-Intr, J. Laosiripisan, and J. Wattanapermpool Moderate intensity of regular exercise improves cardiac SR Ca2+ uptake activity in ovariectomized rats J Appl Physiol, October 1, 2009; 107(4): 1105 - 1112. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Wang, Y. Wang, B. Weil, A. Abarbanell, J. Herrmann, J. Tan, M. Kelly, and D. R. Meldrum Estrogen receptor {beta} mediates increased activation of PI3K/Akt signaling and improved myocardial function in female hearts following acute ischemia Am J Physiol Regulatory Integrative Comp Physiol, April 1, 2009; 296(4): R972 - R978. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Z. Cao, L. Liu, W. Packwood, M. Merkel, P. D. Hurn, and D. M. Van Winkle Sex differences in the mechanism of Met5-enkephalin-induced cardioprotection: role of PI3K/Akt Am J Physiol Heart Circ Physiol, January 1, 2008; 294(1): H302 - H310. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. M. Kravtsov, K. W. L. Kam, J. Liu, S. Wu, and T. M. Wong Altered Ca2+ handling by ryanodine receptor and Na+-Ca2+ exchange in the heart from ovariectomized rats: role of protein kinase A Am J Physiol Cell Physiol, May 1, 2007; 292(5): C1625 - C1635. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Thawornkaiwong, J. Pantharanontaga, and J. Wattanapermpool Hypersensitivity of myofilament response to Ca2+ in association with maladaptation of estrogen-deficient heart under diabetes complication Am J Physiol Regulatory Integrative Comp Physiol, February 1, 2007; 292(2): R844 - R851. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Bupha-Intr, J. Wattanapermpool, J. R. Pena, B. M. Wolska, and R. J. Solaro Myofilament response to Ca2+ and Na+/H+ exchanger activity in sex hormone-related protection of cardiac myocytes from deactivation in hypercapnic acidosis Am J Physiol Regulatory Integrative Comp Physiol, February 1, 2007; 292(2): R837 - R843. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Bupha-Intr and J. Wattanapermpool Regulatory role of ovarian sex hormones in calcium uptake activity of cardiac sarcoplasmic reticulum Am J Physiol Heart Circ Physiol, September 1, 2006; 291(3): H1101 - H1108. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. F. Ceylan-Isik, K. H. LaCour, and J. Ren Sex difference in cardiomyocyte function in normal and metallothionein transgenic mice: the effect of diabetes mellitus J Appl Physiol, May 1, 2006; 100(5): 1638 - 1646. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. Pelzer, P.-A. A. Loza, K. Hu, B. Bayer, C. Dienesch, L. Calvillo, J. F. Couse, K. S. Korach, L. Neyses, and G. Ertl Increased Mortality and Aggravation of Heart Failure in Estrogen Receptor-{beta} Knockout Mice After Myocardial Infarction Circulation, March 29, 2005; 111(12): 1492 - 1498. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. Liew, M. A Stagg, J. Chan, P. Collins, and K. T MacLeod Gender determines the acute actions of genistein on intracellular calcium regulation in the guinea-pig heart Cardiovasc Res, January 1, 2004; 61(1): 66 - 76. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
