What question did this study set out to answer?

To evaluate the contribution of coronary constrictor vasomotor tone to the metabolic adaptation and reactive hyperaemic response of the coronary circulation.

January 22, 1963Quarterly Journal of Experimental Physiology and Cognate Medical Sciences

The Physiological Rôle of Coronary Constrictor Fibres. Ii. The Rôle of Coronary Vasomotors in Metabolic Adaptation of the Coronaries

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To evaluate the contribution of coronary constrictor vasomotor tone to the metabolic adaptation and reactive hyperaemic response of the coronary circulation.
Assessed coronary metabolic adaptation using reactive-hyperaemia tests in canines anesthetized with morphine-chloralose.
Manipulated coronary vasomotor tone through unilateral or bilateral carotid artery clamping, surgical or pharmacological vasomotor disruption, and intracoronary vasopressin infusion.
Augmenting coronary constrictor tone via carotid clamping markedly elevated the magnitude of reactive hyperaemic responses relative to control conditions.
Disrupting coronary vasomotor pathways pharmacologically or surgically reduced or eliminated hyperaemic responses, whereas intracoronary vasopressin restored vessel tone and metabolic adaptability.
Diminished constrictor tone led to coronary vessel rigidity, impairing vascular lumen adjustments and myocardial oxygen consumption during heightened cardiac work.

Structured PICO

Population

Dogs under morphine-chloralose narcosis

Intervention

Alteration of coronary constrictor tone via clamping carotids, pharmacological or surgical interruption of coronary vasomotor pathways, and intracoronary administration of vasopressin

Comparator

Reactions during the control period

Outcome

Degree of hyperemic responses evaluated by the reactive-hyperemia testsurrogate

Coronary vasomotor constrictor tone serves as a necessary reserve for metabolic adaptation of the coronaries, and its loss leads to vessel rigidity analogous to angina pectoris.

Discussion

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Implication

Coronary constrictor tone supports metabolic adaptation in canines; leaves open its role in human coronary reserve and angina.

Cite This Study

Szentiványi et al. (1963) studied this question.

synapsesocial.com/papers/6a82df44ac779081c023bb40 https://doi.org/10.1113/expphysiol.1963.sp001630

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The Physiological Rôle of Coronary Constrictor Fibres. Ii. The Rôle of Coronary Vasomotors in Metabolic Adaptation of the Coronaries

Key Points

Structured PICO

Discussion

Implication

Cite This Study

The Physiological Rôle of Coronary Constrictor Fibres. Ii. The Rôle of Coronary Vasomotors in Metabolic Adaptation of the Coronaries

Key Points

Structured PICO

Discussion

Implication

Cite This Study

Also Consider

Also Consider