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. 1993 Dec;472:785–799. doi: 10.1113/jphysiol.1993.sp019973

Afferent discharges from coronary arterial and ventricular receptors in anaesthetized dogs.

M J Drinkhill 1, J Moore 1, R Hainsworth 1
PMCID: PMC1160513  PMID: 8145172

Abstract

1. Previous work has shown that increases in aortic root pressure result in reflex vasodilation, and that this response is likely to result mainly from stimulation of receptors in the coronary arteries, although contribution from left ventricular receptors was not excluded. This investigation was undertaken to resolve this question and to determine the afferent nerve fibres likely to be involved in this reflex. 2. In chloralose-anaesthetized dogs a perfusion circuit was used which allowed us to change the pressures in: (a) the aortic root, coronary arteries and the left ventricle; (b) aortic root and coronary arteries at constant ventricular pressure; and (c) the left ventricle with mean (although not pulse) aortic pressure constant. Electrophysiological recordings were made from slips dissected from the vagus nerve which responded with an increase in discharge to either combined increases in the pressures, or to aortic root injections of veratridine. 3. Recordings were made from twenty-one vagal afferents. On the basis of their conduction velocities, eleven were classified as non-myelinated and ten as myelinated. 4. Three non-myelinated afferents responded to veratridine injections only, three to both veratridine and combined aortic root and ventricular pressure changes, and five to pressure changes only. Responses to pressure occurred only when ventricular systolic pressure exceeded 30 kPa. 5. None of the myelinated afferents responded to veratridine. All showed increases in discharge to combined increases in mean aortic root, coronary arterial and left ventricular systolic pressures, which would be graded over a range similar to that which caused reflex changes. All were more sensitive to changes in mean coronary pressure than to changes in ventricular systolic pressure. 6. We conclude that myelinated vagal afferent nerve fibres, which respond predominantly to changes in mean coronary arterial pressure, are likely to be responsible for the vasodilation to the changes in mean aortic root pressure previously reported. These fibres are probably attached to coronary arterial mechanoreceptors.

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Selected References

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  1. Angell James J. E. The effects of altering mean pressure, pulse pressure and pulse frequency on the impulse activity in baroreceptor fibres from the aortic arch and right subclavian artery in the rabbit. J Physiol. 1971 Apr;214(1):65–88. doi: 10.1113/jphysiol.1971.sp009419. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Arndt J. O., Morgenstern J., Samodelov L. The physiologically relevant information regarding systemic blood pressure encoded in the carotid sinus baroreceptor discharge pattern. J Physiol. 1977 Jul;268(3):775–791. doi: 10.1113/jphysiol.1977.sp011881. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. BROWN A. M. MECHANORECEPTORS IN OR NEAR THE CORONARY ARTERIES. J Physiol. 1965 Mar;177:203–214. doi: 10.1113/jphysiol.1965.sp007586. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Bergel D. H., Makin G. S. Central and peripheral cardiovascular changes following chemical stimulation of the surface of the dog's heart. Cardiovasc Res. 1967 Jan;1(1):80–90. doi: 10.1093/cvr/1.1.80. [DOI] [PubMed] [Google Scholar]
  5. COLERIDGE H. M., COLERIDGE J. C., KIDD C. CARDIAC RECEPTORS IN THE DOG, WITH PARTICULAR REFERENCE TO TWO TYPES OF AFFERENT ENDING IN THE VENTRICULAR WALL. J Physiol. 1964 Nov;174:323–339. doi: 10.1113/jphysiol.1964.sp007490. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. COLERIDGE J. C., HEMINGWAY A., HOLMES R. L., LINDEN R. J. The location of atrial receptors in the dog: a physiological and histological study. J Physiol. 1957 Apr 3;136(1):174–197. doi: 10.1113/jphysiol.1957.sp005750. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Challenger S., McGregor K. H., Hainsworth R. Peripheral vascular responses to changes in left ventricular pressure in anaesthetized dogs. Q J Exp Physiol. 1987 Jul;72(3):271–283. doi: 10.1113/expphysiol.1987.sp003074. [DOI] [PubMed] [Google Scholar]
  8. Gupta B. N., Thames M. D. Behavior of left ventricular mechanoreceptors with myelinated and nonmyelinated afferent vagal fibers in cats. Circ Res. 1983 Mar;52(3):291–301. doi: 10.1161/01.res.52.3.291. [DOI] [PubMed] [Google Scholar]
  9. Hainsworth R., McGregor K. H., Ford R. Effect of veratridine injected into the aortic root on resistance and capacitance in the abdominal circulation in anaesthetized dogs. Q J Exp Physiol. 1986 Oct;71(4):589–598. doi: 10.1113/expphysiol.1986.sp003019. [DOI] [PubMed] [Google Scholar]
  10. Hainsworth R. Reflexes from the heart. Physiol Rev. 1991 Jul;71(3):617–658. doi: 10.1152/physrev.1991.71.3.617. [DOI] [PubMed] [Google Scholar]
  11. Kaufman M. P., Baker D. G., Coleridge H. M., Coleridge J. C. Stimulation by bradykinin of afferent vagal C-fibers with chemosensitive endings in the heart and aorta of the dog. Circ Res. 1980 Apr;46(4):476–484. doi: 10.1161/01.res.46.4.476. [DOI] [PubMed] [Google Scholar]
  12. McGregor K. H., Hainsworth R., Ford R. Hind-limb vascular responses in anaesthetized dogs to aortic root injections of veratridine. Q J Exp Physiol. 1986 Oct;71(4):577–587. doi: 10.1113/expphysiol.1986.sp003018. [DOI] [PubMed] [Google Scholar]
  13. Oberg B., Thorén P. Studies on left ventricular receptors, signalling in non-medullated vagal afferents. Acta Physiol Scand. 1972 Jun;85(2):145–163. doi: 10.1111/j.1748-1716.1972.tb05246.x. [DOI] [PubMed] [Google Scholar]
  14. PAINTAL A. S. A study of ventricular pressure receptors and their role in the Bezold reflex. Q J Exp Physiol Cogn Med Sci. 1955 Oct;40(4):348–363. doi: 10.1113/expphysiol.1955.sp001135. [DOI] [PubMed] [Google Scholar]
  15. Thames M. D., Donald D. E., Shepherd J. T. Behavior of cardiac receptors with nonmyelinated vagal afferents during spontaneous respiration in cats. Circ Res. 1977 Nov;41(5):694–701. doi: 10.1161/01.res.41.5.694. [DOI] [PubMed] [Google Scholar]
  16. Thorén P. Left ventricular receptors activated by severe asphyxia and by coronary artery occlusion. Acta Physiol Scand. 1972 Aug;85(4):455–463. doi: 10.1111/j.1748-1716.1971.tb05283.x. [DOI] [PubMed] [Google Scholar]
  17. Thorén P., Saum W. R., Brown A. M. Characteristics of rat aortic baroreceptors with nonmedullated afferent nerve fibers. Circ Res. 1977 Mar;40(3):231–237. doi: 10.1161/01.res.40.3.231. [DOI] [PubMed] [Google Scholar]
  18. Tutt S. M., McGregor K. H., Hainsworth R. Reflex vascular responses to changes in left ventricular pressure in anaesthetized dogs. Q J Exp Physiol. 1988 May;73(3):425–437. doi: 10.1113/expphysiol.1988.sp003158. [DOI] [PubMed] [Google Scholar]
  19. Vukasovic J. L., Tutt S. M., Crisp A. J., Hainsworth R. The influence of left ventricular pressure on the vascular responses to changes in carotid sinus pressure in anaesthetized dogs. Q J Exp Physiol. 1989 Sep;74(5):735–746. doi: 10.1113/expphysiol.1989.sp003325. [DOI] [PubMed] [Google Scholar]
  20. al-Timman J. K., Drinkhill M. J., Hainsworth R. Reflex responses to stimulation of mechanoreceptors in the left ventricle and coronary arteries in anaesthetized dogs. J Physiol. 1993 Dec;472:769–783. doi: 10.1113/jphysiol.1993.sp019972. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. al-Timman J. K., Hainsworth R. Reflex vascular responses to changes in left ventricular pressures, heart rate and inotropic state in dogs. Exp Physiol. 1992 May;77(3):455–469. doi: 10.1113/expphysiol.1992.sp003606. [DOI] [PubMed] [Google Scholar]

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