Endothelium-removal decreases relaxations of canine coronary arteries caused by β-adrenergic agonists and adenosine

摘要: Experiments were designed to investigate the importance of endothelium in relaxation isolated coronary arteries caused by beta-adrenoceptor agonists or adenosine. Rings canine left circumflex suspended for isometric tension recording organ chambers filled with physiological salt solution. Norepinephrine, isoproterenol, adenosine, acetylcholine, and sodium nitroprusside relaxations control rings contracted prostaglandin F2 alpha KCl. The all substances tested relatively smaller during contractions evoked KCl than those alpha. Mechanical removal abolished reduced catecholamines did not affect Endothelium-removal beta-adrenergic adenosine after pretreatment indomethacin. Indomethacin responses acetylcholine nitroprusside, but augmented response stimulation These results suggest that endothelial cells artery produce a signal which facilitates direct inhibitory action these on vascular smooth muscle.