Skip to main content
PMC home page
Journal of Anatomy logoLink to Journal of Anatomy
. 1999 Oct;195(Pt 3):341–357. doi: 10.1046/j.1469-7580.1999.19530341.x

Localisation and quantitation of autonomic innervation in the porcine heart I: conduction system

SIMON J CRICK 1 ,✉, MARY N SHEPPARD 2 , SIEW YEN HO 1 , ROBERT H ANDERSON 1
PMCID: PMC1468004  PMID: 10580850

Abstract

This study was prompted by the prospect of transgenic pigs providing donor hearts for transplantation in human recipients. Autonomic innervation is important for the control of cardiac dynamics, especially in the conduction system. Our objective was to assess the relative distribution of autonomic nerves in the pig heart, focusing initially on the conduction system but addressing also the myocardium, endocardium and epicardium (see Crick et al. 1999). Quantitative immunohistochemical and histochemical techniques were adopted. All regions of the conduction system possessed a significantly higher relative density of the total neural population immunoreactive for the general neuronal marker protein gene product 9.5 (PGP 9.5) than did the adjacent myocardium. A similar density of PGP 9.5-immunoreactive innervation was observed between the sinus node, the transitional region of the atrioventricular node, and the penetrating atrioventricular bundle. A differential pattern of PGP 9.5-immunoreactive innervation was present within the atrioventricular node and between the components of the ventricular conduction tissues, the latter being formed by an intricate network of Purkinje fibres. Numerous ganglion cell bodies were present in the peripheral regions of the sinus node, in the tissues of the atrioventricular groove, and even in the interstices of the compact atrioventricular node. Acetylcholinesterase (AChE)-containing nerves were the dominant subpopulation observed, representing 60–70% of the total pattern of innervation in the nodal tissues and penetrating atrioventricular bundle. Tyrosine hydroxylase (TH)-immunoreactive nerves were the next most abundant neural subpopulation, representing 37% of the total pattern of innervation in the compact atrioventricular node compared with 25% in the transitional nodal region. A minor population of ganglion cell bodies within the atrioventricular nodal region displayed TH immunoreactivity. The dominant peptidergic nerve supply possessed immunoreactivity for neuropeptide Y (NPY), which displayed a similar pattern of distribution to that of TH-immunoreactive nerve fibres. Calcitonin gene-related peptide (CGRP)-immunoreactive nerves represented 8–9% of the total innervation of the nodal tissues and penetrating atrioventricular bundle, increasing to 14–19% in the bundle branches. Somatostatin-immunoreactive nerve fibres were relatively sparse (4–13% of total innervation) and were most abundant in the nodes, especially the compact atrioventricular node. The total pattern of innervation of the porcine conduction system was relatively homogeneous. A substantial proportion of nerve fibres innervating the nodal tissues could be traced to intracardiac ganglia indicative of an extensive intrinsic supply. The innervation of the atrioventricular node and ventricular conduction tissues was similar to that observed in the bovine heart, but markedly different to that of the human heart. It is important that we are aware of these findings in view of the future use of transgenic pig hearts in human xenotransplantation.

Keywords: Cardiac conduction system, autonomic nervous system, xenotransplantation

Full Text

The Full Text of this article is available as a PDF (1.3 MB).

Selected References

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

  1. Allen T. G., Burnstock G. Intracellular studies of the electrophysiological properties of cultured intracardiac neurones of the guinea-pig. J Physiol. 1987 Jul;388:349–366. doi: 10.1113/jphysiol.1987.sp016618. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Ardell J. L., Butler C. K., Smith F. M., Hopkins D. A., Armour J. A. Activity of in vivo atrial and ventricular neurons in chronically decentralized canine hearts. Am J Physiol. 1991 Mar;260(3 Pt 2):H713–H721. doi: 10.1152/ajpheart.1991.260.3.H713. [DOI] [PubMed] [Google Scholar]
  3. Armour J. A., Collier K., Kember G., Ardell J. L. Differential selectivity of cardiac neurons in separate intrathoracic autonomic ganglia. Am J Physiol. 1998 Apr;274(4 Pt 2):R939–R949. doi: 10.1152/ajpregu.1998.274.4.R939. [DOI] [PubMed] [Google Scholar]
  4. Armour J. A., Murphy D. A., Yuan B. X., Macdonald S., Hopkins D. A. Gross and microscopic anatomy of the human intrinsic cardiac nervous system. Anat Rec. 1997 Feb;247(2):289–298. doi: 10.1002/(SICI)1097-0185(199702)247:2<289::AID-AR15>3.0.CO;2-L. [DOI] [PubMed] [Google Scholar]
  5. Bowman T. A., Hughes H. C. Swine as an in vivo model for electrophysiologic evaluation of cardiac pacing parameters. Pacing Clin Electrophysiol. 1984 Mar;7(2):187–194. doi: 10.1111/j.1540-8159.1984.tb04885.x. [DOI] [PubMed] [Google Scholar]
  6. Bowman T. A., Hughes H. C. Ventriculoatrial conduction in swine during cardiac pacing: animal model for retrograde conduction. Am Heart J. 1984 Aug;108(2):337–341. doi: 10.1016/0002-8703(84)90621-5. [DOI] [PubMed] [Google Scholar]
  7. Butler C. K., Smith F. M., Cardinal R., Murphy D. A., Hopkins D. A., Armour J. A. Cardiac responses to electrical stimulation of discrete loci in canine atrial and ventricular ganglionated plexi. Am J Physiol. 1990 Nov;259(5 Pt 2):H1365–H1373. doi: 10.1152/ajpheart.1990.259.5.H1365. [DOI] [PubMed] [Google Scholar]
  8. Chow L. T., Chow S. S., Anderson R. H., Gosling J. A. Innervation of the human cardiac conduction system at birth. Br Heart J. 1993 May;69(5):430–435. doi: 10.1136/hrt.69.5.430. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Chow L. T., Chow S. S., Anderson R. H., Gosling J. A. The innervation of the human myocardium at birth. J Anat. 1995 Aug;187(Pt 1):107–114. [PMC free article] [PubMed] [Google Scholar]
  10. Cozzi E., White D. J. The generation of transgenic pigs as potential organ donors for humans. Nat Med. 1995 Sep;1(9):964–966. doi: 10.1038/nm0995-964. [DOI] [PubMed] [Google Scholar]
  11. Crick S. J., Anderson R. H., Ho S. Y., Sheppard M. N. Localisation and quantitation of autonomic innervation in the porcine heart II: endocardium, myocardium and epicardium. J Anat. 1999 Oct;195(Pt 3):359–373. doi: 10.1046/j.1469-7580.1999.19530359.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Crick S. J., Sheppard M. N., Anderson R. H., Polak J. M., Wharton J. A quantitative assessment of innervation in the conduction system of the calf heart. Anat Rec. 1996 Aug;245(4):685–698. doi: 10.1002/(SICI)1097-0185(199608)245:4<685::AID-AR9>3.0.CO;2-N. [DOI] [PubMed] [Google Scholar]
  13. Crick S. J., Sheppard M. N., Anderson R. H., Polak J. M., Wharton J. A quantitative study of nerve distribution in the conduction system of the guinea pig heart. J Anat. 1996 Apr;188(Pt 2):403–416. [PMC free article] [PubMed] [Google Scholar]
  14. Crick S. J., Sheppard M. N., Ho S. Y., Gebstein L., Anderson R. H. Anatomy of the pig heart: comparisons with normal human cardiac structure. J Anat. 1998 Jul;193(Pt 1):105–119. doi: 10.1046/j.1469-7580.1998.19310105.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Crick S. J., Wharton J., Sheppard M. N., Royston D., Yacoub M. H., Anderson R. H., Polak J. M. Innervation of the human cardiac conduction system. A quantitative immunohistochemical and histochemical study. Circulation. 1994 Apr;89(4):1697–1708. doi: 10.1161/01.cir.89.4.1697. [DOI] [PubMed] [Google Scholar]
  16. Day S. M., Gu J., Polak J. M., Bloom S. R. Somatostatin in the human heart and comparison with guinea pig and rat heart. Br Heart J. 1985 Feb;53(2):153–157. doi: 10.1136/hrt.53.2.153. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. De Biasi S., Vitellaro-Zuccarello L., Blum I. Histochemical and ultrastructural study on the innervation of human and porcine atrio-ventricular valves. Anat Embryol (Berl) 1984;169(2):159–165. doi: 10.1007/BF00303145. [DOI] [PubMed] [Google Scholar]
  18. De Biasi S., Vitellaro-Zuccarello L. Intrinsic innervation of porcine semilunar heart valves. Anat Embryol (Berl) 1982 Sep;165(1):71–79. doi: 10.1007/BF00304584. [DOI] [PubMed] [Google Scholar]
  19. Douglas W. R. Of pigs and men and research: a review of applications and analogies of the pig, sus scrofa, in human medical research. Space Life Sci. 1972 Jun;3(3):226–234. doi: 10.1007/BF00928167. [DOI] [PubMed] [Google Scholar]
  20. Forsgren S. Distribution of calcitonin gene-related peptide-like immunoreactivity in the bovine conduction system: correlation with substance P. Regul Pept. 1994 Jun 16;52(1):7–19. doi: 10.1016/0167-0115(94)90016-7. [DOI] [PubMed] [Google Scholar]
  21. Forsgren S. Neuropeptide Y-like immunoreactivity in relation to the distribution of sympathetic nerve fibers in the heart conduction system. J Mol Cell Cardiol. 1989 Mar;21(3):279–290. doi: 10.1016/0022-2828(89)90743-8. [DOI] [PubMed] [Google Scholar]
  22. Forsgren S. The distribution of terminal sympathetic nerve fibers in bundle branches and false tendons of the bovine heart. An immunohistochemical and catecholamine histofluorescence study. Anat Embryol (Berl) 1988;177(5):437–443. doi: 10.1007/BF00304741. [DOI] [PubMed] [Google Scholar]
  23. Franco-Cereceda A., Henke H., Lundberg J. M., Petermann J. B., Hökfelt T., Fischer J. A. Calcitonin gene-related peptide (CGRP) in capsaicin-sensitive substance P-immunoreactive sensory neurons in animals and man: distribution and release by capsaicin. Peptides. 1987 Mar-Apr;8(2):399–410. doi: 10.1016/0196-9781(87)90117-3. [DOI] [PubMed] [Google Scholar]
  24. Franco-Cereceda A., Lundberg J. M., Hökfelt T. Somatostatin: an inhibitory parasympathetic transmitter in the human heart? Eur J Pharmacol. 1986 Dec 2;132(1):101–102. doi: 10.1016/0014-2999(86)90019-1. [DOI] [PubMed] [Google Scholar]
  25. Gagliardi M., Randall W. C., Bieger D., Wurster R. D., Hopkins D. A., Armour J. A. Activity of in vivo canine cardiac plexus neurons. Am J Physiol. 1988 Oct;255(4 Pt 2):H789–H800. doi: 10.1152/ajpheart.1988.255.4.H789. [DOI] [PubMed] [Google Scholar]
  26. Gordon L., Polak J. M., Moscoso G. J., Smith A., Kuhn D. M., Wharton J. Development of the peptidergic innervation of human heart. J Anat. 1993 Aug;183(Pt 1):131–140. [PMC free article] [PubMed] [Google Scholar]
  27. Gordon L., Wharton J., Gaer J. A., Inglis G. C., Taylor K. M., Polak J. M. Quantitative immunohistochemical assessment of bovine myocardial innervation before and after cryosurgical cardiac denervation. Cardiovasc Res. 1993 Feb;27(2):318–326. doi: 10.1093/cvr/27.2.318. [DOI] [PubMed] [Google Scholar]
  28. Hassall C. J., Penketh R., Rodeck C., Burnstock G. The intracardiac neurones of the fetal human heart in culture. Anat Embryol (Berl) 1990;182(4):329–337. doi: 10.1007/BF02433493. [DOI] [PubMed] [Google Scholar]
  29. Hopkins D. A., Gootman P. M., Gootman N., Di Russo S. M., Zeballos M. E. Brainstem cells of origin of the cervical vagus and cardiopulmonary nerves in the neonatal pig (Sus scrofa). Brain Res. 1984 Jul 23;306(1-2):63–72. doi: 10.1016/0006-8993(84)90356-1. [DOI] [PubMed] [Google Scholar]
  30. Hughes H. C. Swine in cardiovascular research. Lab Anim Sci. 1986 Aug;36(4):348–350. [PubMed] [Google Scholar]
  31. Macdonald A. A., Poot P., Wensing C. J. Nerve endings in the pulmonary trunk, ductus arteriosus and aorta of intact and decapitated pig fetuses. Anat Embryol (Berl) 1983;168(3):395–404. doi: 10.1007/BF00304276. [DOI] [PubMed] [Google Scholar]
  32. Moravec J., Moravec M. Intrinsic nerve plexus of mammalian heart: morphological basis of cardiac rhythmical activity? Int Rev Cytol. 1987;106:89–148. doi: 10.1016/s0074-7696(08)61711-8. [DOI] [PubMed] [Google Scholar]
  33. Moravec M., Courtalon A., Moravec J. Intrinsic neurosecretory neurons of the rat heart atrioventricular junction: possibility of local neuromuscular feed back loops. J Mol Cell Cardiol. 1986 Apr;18(4):357–367. doi: 10.1016/s0022-2828(86)80899-9. [DOI] [PubMed] [Google Scholar]
  34. Moravec M., Moravec J. Adrenergic neurons and short proprioceptive feedback loops involved in the integration of cardiac function in the rat. Cell Tissue Res. 1989 Nov;258(2):381–385. doi: 10.1007/BF00239458. [DOI] [PubMed] [Google Scholar]
  35. Murphy D. A., O'Blenes S., Hanna B. D., Armour J. A. Capacity of intrinsic cardiac neurons to modify the acutely autotransplanted mammalian heart. J Heart Lung Transplant. 1994 Sep-Oct;13(5):847–856. [PubMed] [Google Scholar]
  36. Opthof T., de Jonge B., Jongsma H. J., Bouman L. N. Functional morphology of the pig sinoatrial node. J Mol Cell Cardiol. 1987 Dec;19(12):1221–1236. doi: 10.1016/s0022-2828(87)80532-1. [DOI] [PubMed] [Google Scholar]
  37. Petrecca K., Shrier A. Spatial distribution of nerve processes and beta-adrenoreceptors in the rat atrioventricular node. J Anat. 1998 May;192(Pt 4):517–528. doi: 10.1046/j.1469-7580.1998.19240517.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  38. Priola D. V. Intrinsic innervation of the canine heart. Effects on conduction in the atrium, atrioventricular node, and proximal bundle branch. Circ Res. 1980 Jul;47(1):74–79. doi: 10.1161/01.res.47.1.74. [DOI] [PubMed] [Google Scholar]
  39. Schemann M., Sann H., Schaaf C., Mäder M. Identification of cholinergic neurons in enteric nervous system by antibodies against choline acetyltransferase. Am J Physiol. 1993 Nov;265(5 Pt 1):G1005–G1009. doi: 10.1152/ajpgi.1993.265.5.G1005. [DOI] [PubMed] [Google Scholar]
  40. Selyanko A. A., Skok V. I. Synaptic transmission in rat cardiac neurones. J Auton Nerv Syst. 1992 Jul;39(3):191–199. doi: 10.1016/0165-1838(92)90012-6. [DOI] [PubMed] [Google Scholar]
  41. Singh S., Johnson P. I., Lee R. E., Orfei E., Lonchyna V. A., Sullivan H. J., Montoya A., Tran H., Wehrmacher W. H., Wurster R. D. Topography of cardiac ganglia in the adult human heart. J Thorac Cardiovasc Surg. 1996 Oct;112(4):943–953. doi: 10.1016/S0022-5223(96)70094-6. [DOI] [PubMed] [Google Scholar]
  42. Smith F. M., Hopkins D. A., Armour J. A. Electrophysiological properties of in vitro intrinsic cardiac neurons in the pig (Sus scrofa). Brain Res Bull. 1992 May;28(5):715–725. doi: 10.1016/0361-9230(92)90251-r. [DOI] [PubMed] [Google Scholar]
  43. Tranum-Jensen J. The ultrastructure of the sensory end-organs (baroreceptors) in the atrial endocardium of young mini-pigs. J Anat. 1975 Apr;119(Pt 2):255–275. [PMC free article] [PubMed] [Google Scholar]
  44. Webb S. C., Krikler D. M., Hendry W. G., Adrian T. E., Bloom S. R. Electrophysiological actions of somatostatin on the atrioventricular junction in sinus rhythm and reentry tachycardia. Br Heart J. 1986 Sep;56(3):236–241. doi: 10.1136/hrt.56.3.236. [DOI] [PMC free article] [PubMed] [Google Scholar]
  45. Wharton J., Gulbenkian S., Merighi A., Kuhn D. M., Jahn R., Taylor K. M., Polak J. M. Immunohistochemical and ultrastructural localisation of peptide-containing nerves and myocardial cells in the human atrial appendage. Cell Tissue Res. 1988 Oct;254(1):155–166. doi: 10.1007/BF00220029. [DOI] [PubMed] [Google Scholar]
  46. Wharton J., Polak J. M., Gordon L., Banner N. R., Springall D. R., Rose M., Khagani A., Wallwork J., Yacoub M. H. Immunohistochemical demonstration of human cardiac innervation before and after transplantation. Circ Res. 1990 Apr;66(4):900–912. doi: 10.1161/01.res.66.4.900. [DOI] [PubMed] [Google Scholar]
  47. White D., Wallwork J. Xenografting: probability, possibility, or pipe dream? Lancet. 1993 Oct 9;342(8876):879–880. doi: 10.1016/0140-6736(93)91939-j. [DOI] [PubMed] [Google Scholar]

Articles from Journal of Anatomy are provided here courtesy of Anatomical Society of Great Britain and Ireland

RESOURCES