Coronary Vascular and
Aortic Endothelial Permeability During Estrogen Therapy: A Study
in DOCA-Salt Hypertensive Ovariectomized Rats
M. KHAZAEI, M. NEMATBAKHSH
Department of Physiology, School of Medicine, Medical University
of Science, Isfahan, Iran
Received September 29, 2003
Accepted January 29, 2004
Summary
Cardiovascular disease (CVD) is a major source of morbidity and
mortality in the Western World. Premenopausal and
estrogen-treated postmenopausal women have a lower incidence of
CVD. It has been suggested that circulating endogenous estrogens
are probably responsible for this protection. This study
investigated the hypothesis that the reduction of endothelial
permeability is responsible for cardioprotective effects of
estrogen in hypertensive animals. Fourty-four rats were
ovariectomized and divided into five groups: groups 1, 2 and 4
received DOCA-salt and groups 3 and 5 received normal saline
(N/S) injection for four weeks. Then, in groups 4 and 5 the
blood pressure was measured. Group 1 received estradiol valerate
and in groups 2 and 3 continued with DOCA-salt and N/S injection
for six weeks, respectively. Endothelial permeability was
measured by Evans Blue extraction method. There was no
significant difference in endothelial permeability in coronary
circulation in estrogen-treated group and controls (12.97±2.32
vs. 9.96±1.01, respectively). Also, aortic endothelial
permeability in DOCA-salt hypertensive rats did not change
significantly after estrogen treatment (28.34±3.65 vs.
41.60±5.98). This study showed that the cardioprotective effects
of estrogen in DOCA-salt hypertensive animals are not mediated
by a reduction of endothelial permeability.
Key words
Aorta • Coronary artery • Endothelial permeability • Estrogen •
Hypertension
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