Skip to main content
NCBI home page
The Journal of Physiology logoLink to The Journal of Physiology
. 1972 Mar;221(2):283–309. doi: 10.1113/jphysiol.1972.sp009752

Action potentials from ventricular mechanoreceptors stimulated by occlusion of the coronary sinus in the dog

M F Muers, P Sleight
PMCID: PMC1331334  PMID: 5020979

Abstract

1. In experiments to determine the type of intra-cardiac receptors which cause the coronary sinus occlusion reflex, recordings were made from sixty-nine single and small multi-fibre preparations of cardiac vagal afferents in open-chest anaesthetized dogs.

2. Thirty-two fibres were stimulated by occlusion of the coronary sinus outflow through an indwelling Morawitz cannula. No receptors were stimulated during occlusions at peak systolic coronary venous pressures below the threshold for reflex cardiovascular depression. At higher pressures, fibre recruitment and further increases in stimulated discharge were demonstrated.

3. The afferent endings of twenty-nine of these fibres were mechanically localized to the epicardium and myocardium of the left ventricle. Three were in the right ventricle. Seventeen single fibres discharged spontaneously at an average of 0·9 impulses/sec. There was cardiac modulation of both resting and stimulated discharge, with most action potentials in systole. Seven of eight fibres conducted at less than 1·0 m/sec.

4. These ventricular receptors and a further twenty-two otherwise like them but not stimulated by occlusions were designated epi-myocardial receptors.

5. 73% of receptors were stimulated by intrapericardial nicotine (50-100 μg). Presumptively superficial receptors were more sensitive to this stimulus.

6. Epi-myocardial receptors were stimulated by intravenous or intracoronary catecholamines, by electrical stimulation of cardiac sympathetic nerves, and by eliciting the carotid sinus occlusion reflex. Aortic occlusion stimulated 66% of fibres tested, but was a less effective stimulus. After all these stimuli, there was a systolic modulation of discharge in more than 70% of fibres.

7. It was concluded that the epi-myocardial receptors are similar to those previously shown to cause the epicardial chemoreflex, and to participate in the coronary chemoreflex. It is suggested that they are responsive to systolic mechanical changes which are accentuated by catecholamines. Their possible effectiveness in other cardiac reflexes and in initiating circulatory changes at the beginning of exercise and the vasovagal syndrome is discussed.

Full text

PDF
283

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. 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]
  2. 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]
  3. 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]
  4. DAWES G. S., COMROE J. H., Jr Chemoreflexes from the heart and lungs. Physiol Rev. 1954 Apr;34(2):167–201. doi: 10.1152/physrev.1954.34.2.167. [DOI] [PubMed] [Google Scholar]
  5. FERGUSON T. B., SHADLE O. W., GREGG D. E. Effect of blood and saline infusion on ventricular end diastolic pressure, stroke work, stroke volume and cardiac output in the open and closed chest dog. Circ Res. 1953 Jan;1(1):62–68. doi: 10.1161/01.res.1.1.62. [DOI] [PubMed] [Google Scholar]
  6. GONZALEZ SERRATOS H., ERLIJ D. Un reflejo circulatorio de origen coronario. Arch Inst Cardiol Mex. 1958 May-Jun;28(3):404–418. [PubMed] [Google Scholar]
  7. JEWETT D. L. ACTIVITY OF SINGLE EFFERENT FIBRES IN THE CERVICAL VAGUS NERVE OF THE DOG, WITH SPECIAL REFERENCE TO POSSIBLE CARDIO-INHIBITORY FIBRES. J Physiol. 1964 Dec;175:321–357. doi: 10.1113/jphysiol.1964.sp007520. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Muers M. F., Sleight P. The reflex cardiovascular depression caused by occlusion of the coronary sinus in the dog. J Physiol. 1972 Mar;221(2):259–282. doi: 10.1113/jphysiol.1972.sp009751. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. 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]
  10. RUSHMER R. F. Shrinkage of the heart in anesthetized, thoracotomized dogs. Circ Res. 1954 Jan;2(1):22–27. doi: 10.1161/01.res.2.1.22. [DOI] [PubMed] [Google Scholar]
  11. SLEIGHT P. A CARDIOVASCULAR DEPRESSOR REFLEX FROM THE EPICARDIUM OF THE LEFT VENTRICLE IN THE DOG. J Physiol. 1964 Oct;173:321–343. doi: 10.1113/jphysiol.1964.sp007459. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. SZENTIVANYI M., JUHASZ-NAGY A. Two types of coronary vasomotor reflexes. Q J Exp Physiol Cogn Med Sci. 1962 Oct;47:289–298. doi: 10.1113/expphysiol.1962.sp001611. [DOI] [PubMed] [Google Scholar]
  13. Sleight P., Widdicombe J. G. Action potentials in fibres from receptors in the epicardium and myocardium of the dog's left ventricle. J Physiol. 1965 Nov;181(2):235–258. doi: 10.1113/jphysiol.1965.sp007758. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Tiedt N., Litwin J., Skolasinska K. The dynamics of the coronary venous pressure in the dog. Pflugers Arch Gesamte Physiol Menschen Tiere. 1966;288(1):27–42. doi: 10.1007/BF00412533. [DOI] [PubMed] [Google Scholar]
  15. Widdicombe J. G. Action potentials in parasympathetic and sympathetic efferent fibres to the trachea and lungs of dogs and cats. J Physiol. 1966 Sep;186(1):56–88. doi: 10.1113/jphysiol.1966.sp008020. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from The Journal of Physiology are provided here courtesy of The Physiological Society

RESOURCES