Affiliation:
1. Department of Physiology and Biophysics, School of Medicine, University of Washington present address Seattle, Washington 98105
Abstract
The role of the vagus in the control of coronary blood flow was studied in chloralose-anesthetized dogs with open chests. Propranolol, 1.0 mg/kg iv, was used for beta-receptor blockade. Heart rate was maintained at a constant level with atrial and ventricular pacing. Left circumflex coronary artery blood flow was measured with an electromagnetic flowmeter. The experimental design accounted for the four major determinants of coronary blood flow: (1) aortic pressure, (2) myocardial systolic compression, (3) alterations in myocardial oxygen tension and metabolism secondary to changes in contractile force, (4) neural control. Efferent stimulation of the cut cervical vagi (30 Hz, 2 msec, 8-10 v) resulted in decreased aortic blood pressure and increased coronary blood flow. Late diastolic coronary artery resistance fell to 58% of the control value after 5 seconds of vagal stimulation. Atropine, 0.5 mg/kg iv, blocked these effects. It is concluded that direct parasympathetic coronary vasodilation results from vagal stimulation, which is independent of vagal chronotropic and inotropic effects.
Publisher
Ovid Technologies (Wolters Kluwer Health)
Subject
Cardiology and Cardiovascular Medicine,Physiology
Reference39 articles.
1. Innervation of the heart;WOOLLARD H. H.;J. Anat.,1926
2. Untersuchungen iiber einige von den Moinenten, welche Einfluss auf die Herzbewegungen, auf den Stillstand und auf das Aufhoren des Contraktionsvermogens des Herzens haben;PANUM P. L.;Schmidt's Jahrb.,1858
3. Ventilation standards for small mammals
4. An integrating cardiotachometer for optical or pen recording
5. Alterations in ventricular dynamics induced by stimulation of the cervical vagosympathetic trunk;PACE J. B.;Am. J. Physiol.,1968
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