© 1999 by European Society of Cardiology
Copyright © 1999, European Society of Cardiology
Short-term exposure to physiological levels of 17β-estradiol enhances endothelium-independent relaxation in porcine coronary artery1
Department of Pharmacology, Faculty of Medicine, The University of Hong Kong, 1/F Li Shu Fan Building, 5 Sassoon Road, Hong Kong, PR China
* Corresponding author. Tel.: +852-2819-9103; fax: +852-2817-0859. E-mail address: hteoh@hkusua.hku.hk (H. Teoh)
Objectives: While alterations in cholesterol and lipoprotein profiles partly account for menopause being a risk factor for coronary heart disease, recent studies have suggested that 17β-estradiol may have vascular effects. Our aims were to study the short-term effects of 17β-estradiol on vascular function in isolated porcine coronary artery rings. Concomitantly, we sought to determine if physiological concentrations of 17β-estradiol could acutely potentiate relaxation. Results: 17
- and 17β-estradiol at pharmacological (>1 µM) concentrations produced relaxation in U46619
[GenBank]
-pre-contracted porcine coronary artery rings. Relaxation evoked by 17β-estradiol was not reversed by the estrogen receptor antagonists tamoxifen and ICI 182780. Following 20 min exposure to a physiological concentration of 17β-estradiol (1 nM), which on its own had no effect, relaxation elicited by cromakalim, levcromakalim and sodium nitroprusside, but not bradykinin or calcium ionophore A23187
[GenBank]
, were significantly enhanced. This potentiating action was also insensitive to tamoxifen and ICI 182780. Our data provide evidence for an acute indirect relaxant action of 17β-estradiol and suggest that it may be via a tamoxifen- and ICI 182780-insensitive estrogen receptor. While this response was only observed at pharmacological concentrations, the potentiation of cromakalim, levcromakalim and sodium nitroprusside relaxation was evident in the presence of a physiological concentration (1 nM) of 17β-estradiol. Conclusions: These results demonstrate that short-term exposure to 17β-estradiol, at concentrations that have no effect on their own, can enhance vasorelaxation. These vascular effects may partly account for some of the acute effects of 17β-estradiol on blood flow.
KEYWORDS Estradiol; Vessel; Coronary; Vasodilation; Swine
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  T. Traupe, C. D. Stettler, H. Li, E. Haas, I. Bhattacharya, R. Minotti, and M. Barton Distinct Roles of Estrogen Receptors {alpha} and {beta} Mediating Acute Vasodilation of Epicardial Coronary Arteries Hypertension, June 1, 2007; 49(6): 1364 - 1370. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Moritz, R. Gust, and H. H. Pertz Characterization of the Relaxant Response to N,N'-Dipropyl-1,2-bis(2,6-dichloro-4-hydroxyphenyl)ethylenediamine in Porcine Coronary Arteries J. Pharmacol. Exp. Ther., May 1, 2007; 321(2): 699 - 706. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. R. Magness, T. M. Phernetton, T. C. Gibson, and D.-b. Chen Uterine blood flow responses to ICI 182 780 in ovariectomized oestradiol-17{beta}-treated, intact follicular and pregnant sheep J. Physiol., May 15, 2005; 565(1): 71 - 83. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. R. Rouleau, A. Dagnault, D. Simard, B. Lavallee, A. Belanger, A. Blouin, and J. G. Kingma Jr. Effect of estrogen replacement therapy on distribution of myocardial blood flow in female anesthetized rabbits Am J Physiol Heart Circ Physiol, September 1, 2001; 281(3): H1407 - H1412. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. S. Hayward, W. V. Kalnins, and R. P. Kelly Acute effects of 17beta -estradiol on ventricular and vascular hemodynamics in postmenopausal women Am J Physiol Heart Circ Physiol, November 1, 2000; 279(5): H2277 - H2284. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. Teoh, A. Quan, and R. Y.K Man Acute impairment of relaxation by low levels of testosterone in porcine coronary arteries Cardiovasc Res, March 1, 2000; 45(4): 1010 - 1018. [Abstract] [Full Text] [PDF]
|
|