Heterogeneous microvascular coronary alpha-adrenergic 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.

alpha-adrenergic coronary vasoconstriction and myocardial ischemia in humans.

The use of quantitative coronary angiography, combined with Doppler and PET, has recently been directed at the study of alpha-adrenergic coronary vasomotion in humans. Confirming prior animal experiments, there is no evidence of alpha-adrenergic coronary constrictor tone at rest. Again confirming prior experiments, responses to alpha-adrenoceptor activation are augmented in the presence of coro...

Emerging importance of alpha-adrenergic coronary vasoconstriction in acute coronary syndromes and its genetic background.

As compared to the beta-adrenoceptor–mediated effects of sympathetic activation, alpha-adrenoceptor–mediated effects on coronary blood flow have long received little attention. This was largely due to the fact that, in animal experiments under physiologic circumstances, there is very little alpha-adrenergic coronary vasomotor tone at rest, and the increase in coronary blood flow during sympathe...

The paradox of adrenergic coronary vasoconstriction.