A study of ventricular pressure receptors and their role in the Bezold reflex

Paintal, A. S. (1955) A study of ventricular pressure receptors and their role in the Bezold reflex Experimental Physiology, 40 (4). pp. 348-363. ISSN 0958-0670

PDF - Publisher Version

Official URL: http://ep.physoc.org/content/40/4/348.abstract?sid...


1. By recording impulses from single afferent units of the cervical vagus of the cat and localizing the receptor with certainty, it has been established that there are receptors in the right and left ventricles which respond to changes in ventricular pressure. These endings are not chemoreceptors. 2. Relatively few ventricular afferent fibres were found. They were characterized by an early systolic burst of impulses, often timed during the isometric phase of ventricular contraction, and in most fibres this burst terminated before mid-systole. Unlike other cardiovascular fibres, fluctuations in impulse activity during normal respiration were infrequent. 3. These ventricular fibres belong to the A group of medullated fibres, and it is estimated that their mean conduction velocity was between 10-20 m/sec. 4. Left atrial fibres with an early systolic burst of impulses as in ventricular fibres were also encountered, but they were rare. 5. All the ventricular receptors and about a third of the left atrial ones (both types A and B) were stimulated by veriloid and veratridine injected into the right atrium. From a consideration of the significant differences in the responses of the ventricular receptors to veriloid and veratridine respectively, and the parallel significant differences in the reflex cardiovascular responses, it was concluded that the ventricular receptors initiate the Bezold reflex. 6. The left atrial receptors contribute to the Bezold reflex but they do not initiate it following veriloid, and are probably chiefly responsible for the prolonged bradycardia of cardiac origin produced by veratridine. 7. The long delay in stimulating the left atrial receptors suggests that the veriloid alkaloids stimulate the receptors secondary to changes either in the alkaloid or in the immediate environment of the receptors. 8. The right atrial receptors (types A and B) were apparently not stimulated by the drugs, and so in the cat they play no part in the Bezold reflex.

Item Type:Article
Source:Copyright of this article belongs to John Wiley and Sons.
ID Code:37865
Deposited On:23 Apr 2011 11:35
Last Modified:17 May 2016 20:46

Repository Staff Only: item control page