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Effects of Endothelin-1 on the Relaxation of Rat Coronary Arteries
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- ResearcherID
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Abstract
- To analyze the effects of endothelin-1 on the b-adrenergic response of the coronary circulation, 2-mm-long segments of coronary arteries from rats were prepared for isometric tension recording in organ baths. The relaxation to isoproterenol (3 x 10(-8) M), field electrical stimulation (4 Hz, 0.1-millisecond duration, 10 seconds), acetylcholine (3 x 10(-8) M), and sodium nitroprusside (10(-9) M) was recorded in arteries precontracted with U46619 (10(-7) to 5 x 10(-7) M) before and after treatment with endothelin-1 (3 3 10210 and 1029 M). The relaxation to isoproterenol was increased by treatment with endothelin-1 and with the endothelin ET(B) antagonist BQ788 (10(-6) M) but not with the endothelin ET(A) antagonist BQ123 (10(-6) M) or with the blocker of protein kinase C chelerythrine (10(-5) M). In the presence of BQ788, BQ123, or chelerythrine, endothelin-1 did not modify the relaxation to isoproterenol. Treatment with endothelin-1 did not modify the relaxation to electrical stimulation, acetylcholine, or sodium nitroprusside. These results suggest that endothelin-1 may potentiate coronary beta-adrenergic vasodilatation, at least in part due to stimulation of endothelin ET(A) receptors and activation of protein kinase C.
- Subjects :
- Male
medicine.medical_specialty
Vasodilation
Stimulation
In Vitro Techniques
Muscle, Smooth, Vascular
Rats, Sprague-Dawley
chemistry.chemical_compound
Coronary circulation
Thromboxane A2
Internal medicine
Isometric Contraction
medicine
Animals
Vasoconstrictor Agents
Pharmacology
Endothelin-1
Antagonist
Isoproterenol
Adrenergic beta-Agonists
Endothelin 1
Coronary Vessels
Rats
Chelerythrine
Endocrinology
medicine.anatomical_structure
chemistry
15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid
cardiovascular system
Sodium nitroprusside
Cardiology and Cardiovascular Medicine
Acetylcholine
medicine.drug
Subjects
Details
- Database :
- OpenAIRE
- Journal :
- ResearcherID
- Accession number :
- edsair.doi.dedup.....b3a4f904acf3518e0585b4b9e16b8975