The paradox of adrenergic coronary vasoconstriction.

The paradox of adrenergic coronary vasoconstriction.

Heterogeneous microvascular coronary alpha-adrenergic vasoconstriction.

We tested the hypothesis that humoral or neurogenic alpha-adrenergic activation in the coronary circulation would produce heterogeneous vascular reactions. To accomplish this, the epicardial coronary microcirculation was viewed through an intravital microscope using stroboscopic epi-illumination. Microvascular diameters were measured under control conditions during beta-adrenergic blockade (pro...

Alpha Adrenergic Vasoconstriction and Nitroglycerin Vasodilation of Large Coronary

Dr. Vatner was an Established Investigator, American Heart Association. Dr. Pagani's current address is the University of Milan, Milan, Italy. Received for publication 25 January 1979 and in revised form 6 August 1979. active changes. Alpha adrenergic stimulation is sufficiently powerful to reduce cross-sectional area, despite the opposing elevation of distending pressure.

Adrenergic coronary vasoconstriction in the presence of coronary stenosis in the dog.

Previous studies have demonstrated competition between sympathetic alpha receptor-mediated coronary vasoconstriction and local metabolic vasodilation during sympathetic activation. The present study tested if this competition also occurs in the presence of coronary stenosis. In closed-chest dogs, the left coronary artery was cannulated, and blood flow from the aorta was restricted by a moderate...

a-Adrenergic vasoconstriction reduces systolic retrograde coronary blood flow

Koichi Morita, Hidezo Mori, Katsuhiko Tsujioka, Akihiro Kimura, Yasuo Ogasawara, Masami Goto, Osamu Hiramatsu, Fumihiko Kajiya, and Eric O. Feigl. a-Adrenergic vasoconstriction reduces systolic retrograde coronary blood flow. Am. J. Physiol. 273 (Heart Circ. Physiol. 42): H2746–H2755, 1997.—There is a paradoxical a-adrenoceptor-mediated coronary vasoconstriction whenever there is adrenergic act...