Coronary vascular and myocardial responses to carotid body stimulation in the dog.

TitleCoronary vascular and myocardial responses to carotid body stimulation in the dog.
Publication TypeJournal Article
Year of Publication1975
AuthorsEhrhart IC, Parker PE, Weidner WJ, Dabney JM, Scott JB, Haddy FJ
JournalAm J Physiol
Date Published1975 Sep
KeywordsAnimals, Blood Pressure, Carbon Dioxide, Carotid Body, Carotid Sinus, Chemoreceptor Cells, Coronary Circulation, Dogs, Female, Heart, Heart Rate, Hydrogen-Ion Concentration, Male, Oxygen, Perfusion, Pressure, Vagotomy, Vascular Resistance, Ventricular Function

Coronary vascular and myocardial responses to selective hypoxic and/or hypercapnic carotid chemoreceptor stimulation were investigated in constantly ventilated, pentobarbital or urethan-chloralose anesthetized dogs. Bilaterally isolated carotid chemoreceptors were perfused with autologous blood of varying O2 and CO2 tensions via an extracorporeal lung circuit. Systemic gas tensions were unchanged. Effects of carotid chemoreceptor stimulation on coronary vascular resistance, left ventricular dP/dt, and strain-gauge arch output were studied at natural coronary blood flow with the chest closed and during constant-flow perfusion of the left common coronary artery with the chest open. Carotid chemoreceptor stimulation slightly increased left ventricular dP/dt and slightly decreased the strain-gauge arch output, while markedly increasing systemic pressure. Coronary blood flow increased; however, coronary vascular resistance not affected. These studies show that local carotid body stimulation increases coronary blood flow but has little effect on the myocardium. The increase in coronary blood flow results mainly from an increase in systemic arterial pressure. Thus these data provide little evidence for increased sympathetic activity of the heart during local stimulation of the carotid chemoreceptors with hypoxic and hypercapnic blood.

Alternate JournalAm J Physiol
PubMed ID2017

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