Requisite role of cardiac myocytes in coronary alpha(1)-adrenergic constriction

Article

关键词: ARTERIES;    MICROCIRCULATION;    STIMULATION;    ACTIVATION;    RECEPTORS;    RESPONSES;    TONE;    DOG;   

DOI  :  10.1161/01.CIR.98.1.9

来源: SCIE

【 摘 要 】

Background-alpha-Adrenergic activation in vivo causes constriction of coronary arterioles, but, paradoxically, in vitro these microvessels do not contract to this stimulus. We hypothesized that cardiac myocytes have a requisite role in alpha(1)-adrenergic coronary arteriolar constriction through the release of myocyte-derived contractile factor(s). Methods and Results-Administration of the alpha(1)-adrenergic agonist phenylephrine did not constrict isolated coronary arterioles, but constriction was observed to supernatant obtained from phenylephrine-treated cardiac myocytes. Constriction to the supernatant was blocked by administration of an endothelin-A antagonist to the microvessel preparation or an alpha-adrenergic antagonist to the myocytes and was augmented after administration of an adenosine antagonist. Administration of phenylephrine to the myocytes increased endothelin-1 levels in the supernatant, but only to subthreshold concentrations. Conclusions-Cardiac myocytes have a requisite role in constriction of coronary resistance vessels to alpha(1)-adrenergic stimuli, which may be mediated by endothelin-1 and other unidentified myocyte-derived vasoconstrictors.

【 授权许可】

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