Oestrogen relaxes human epicardial coronary arteries through non-endothelium-dependent mechanisms

Autor: Canwen Jiang, Adrian H. Chester, Magdi H. Yacoub, Peter L. Collins, Julie A.A. Borland
Rok vydání: 1995
Předmět:
Adult
Male
medicine.medical_specialty
Adolescent
Endothelium
medicine.medical_treatment
Indomethacin
Myocardial Ischemia
Isometric exercise
In Vitro Techniques
Arginine
Thromboxane A2
chemistry.chemical_compound
Sex Factors
Internal medicine
medicine
Humans
Vasoconstrictor Agents
Lung transplantation
Enzyme Inhibitors
Child
Beta (finance)
omega-N-Methylarginine
Estradiol
biology
business.industry
Estrogen Replacement Therapy
Infant
General Medicine
Middle Aged
Coronary Vessels
Prostaglandin Endoperoxides
Synthetic
Vasodilation
Nitric oxide synthase
Coronary arteries
medicine.anatomical_structure
chemistry
Vasoconstriction
15-Hydroxy-11 alpha
9 alpha-(epoxymethano)prosta-5
13-dienoic Acid
Child
Preschool
biology.protein
Cardiology
Female
Endothelium
Vascular
Cardiology and Cardiovascular Medicine
business
Artery
Zdroj: Coronary Artery Disease. 6:417-422
ISSN: 0954-6928
DOI: 10.1097/00019501-199505000-00009
Popis: BACKGROUND Oestrogen-replacement therapy is associated with a reduced incidence of cardiovascular disease. The acute administration of oestrogen improves myocardial ischemia in women with coronary heart disease. In this study we investigated the relaxing effect of oestradiol-17 beta on human coronary arteries in vitro and determined the role of endothelial modulation in this relaxation by using isolated human coronary arteries. METHODS Atherosclerosis-free epicardial arteries from men and women were removed from patients undergoing heart or combined heart and lung transplantation. The arteries were cut into ring segments and placed into organ baths containing Tyrode's solution. Changes in isometric tension were measured. The relaxing response to oestradiol-17 beta (10(-10) - 10(-5) mol/l) was investigated and the effects of endothelium, NGmonomethyl-L-arginine and indomethacin on the response of oestradiol-17 beta were assessed. RESULTS Oestradiol-17 beta (10(-10) - 10(-5) mol/l) induced significant relaxation in coronary arteries pre-contracted with the thromboxane A2 analog (U46619; 3 x 10(-8) mol/l). Relaxation was significantly greater in coronary arteries from female patients. No significant differences were observed between arteries with or without endothelium nor after nitric oxide synthase or cyclo-oxygenase inhibition. These results indicate that oestradiol-17 beta induces human coronary artery relaxation via an endothelium-independent mechanism in vitro. The sex of the patients significantly affects sensitivity of the coronary arterial rings to oestrogen. CONCLUSION Oestradiol-17 beta-induced coronary relaxation may play an important role in regulation of coronary tone, and may partly explain why oestrogen improves myocardial ischemia in women and why it protects postmenopausal women from the risk of developing coronary heart disease.
Databáze: OpenAIRE
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