Terminal diversification of the myocyte lineage generates Purkinje fibers of the cardiac conduction system

The rhythmic contraction of the vertebrate heart is dependent on organized propagation of electrical excitation through the cardiac conduction system. Because both muscle- and neuron-specific genes are co-expressed in cells forming myocardial conduction tissues, two origins, myogenic and neural, have been suggested for this specialized tissue. Using replication-defective retroviruses, encoding recombinant beta-galactosidase (beta-gal), we have analyzed cell lineage for Purkinje fibers (i.e., the peripheral elements of the conduction system) in the chick heart. Functioning myocyte progenitors were virally tagged at embryonic day 3 of incubation (E3). Clonal beta-gal+ populations of cells, derived from myocytes infected at E3 were examined at 14 (E14) and 18 (E18) days of embryonic incubation. Here, we report that a subset of clonally related myocytes differentiates into conductile Purkinje fibers, invariably in close spatial association with forming coronary arterial blood vessels. These beta-gal+ myogenic clones, containing both working myocytes and Purkinje fibers, did not incorporate cells contributing to tissues of the central conduction system (e.g. atrioventricular ring and bundles). In quantitative analyses, we found that whereas the number of beta-gal+ myocyte nuclei per clone more than doubled between E14 and E18, the number of beta-gal+ Purkinje fiber nuclei remained constant.(ABSTRACT TRUNCATED AT 250 WORDS)

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Why Do We Have Purkinje Fibers Deep in Our Heart?

Physiological Research ◽

10.33549/physiolres.932686 ◽

2014 ◽

pp. S9-S18 ◽

Cited By ~ 18

Author(s):

D. SEDMERA ◽

R. G. GOURDIE

Keyword(s):

Conduction System ◽

Human Anatomy ◽

Cardiac Conduction ◽

Cardiac Conduction System ◽

Model Species ◽

Purkinje Fibers ◽

Current State

Purkinje fibers were the first discovered component of the cardiac conduction system. Originally described in sheep in 1839 as pale subendocardial cells, they were found to be present, although with different morphology, in all mammalian and avian hearts. Here we review differences in their appearance and extent in different species, summarize the current state of knowledge of their function, and provide an update on markers for these cells. Special emphasis is given to popular model species and human anatomy.

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Dynamical behavior of cardiac conduction system under external disturbances: simulation based on microcontroller technology

Physica Scripta ◽

10.1088/1402-4896/ac47ba ◽

2022 ◽

Author(s):

Rodrigue Fonkou ◽

Patrick Louodop ◽

Pierre Kisito Talla

Keyword(s):

Blood Pressure ◽

Electric Current ◽

Sinus Node ◽

Dynamical Behavior ◽

Heart Rhythm ◽

Conduction System ◽

Cardiac Conduction ◽

Cardiac Conduction System ◽

Very High Frequency ◽

Purkinje Fibers

Abstract The heart rhythm is one of the most interesting aspects of the dynamic behavior of biological systems. Understanding heart rhythms is essential in the dynamic analysis of the heart. Each type of dynamic behaviour can describe normal or pathological physiology. The heart is made up of nodes ranging from SA node (natural pacemaker) to Purkinje fibers. The electric current originates in the sinus node and travels through the heart until it reaches the Purkinje fibers, causing after its passage through each of the nodes a heartbeat thus constituting the electrocardiogram (ECG). Since the origin of the electric current is the sinus node, in this article we study numerically and experimentally by microcontroller the influence of the sinus node on the propagation of electric current through the heart. A study of the sinus node in its autonomous state shows us that in their coupled state, the nodes of the heart qualitatively reproduce the time series of the action potential of this latter, which leads to the recording of the ECG. A study when the sinus node is subjected to periodic pulsed excitation E 1(t) = kP(t), assumed to come from blood pressure, with P(t) the blood pressure, shows that for some selected frequencies, it is found that the nodes of the heart and the ECG exhibit responses having the same shape and the same frequencies as those of the pulsatile blood pressure. This suggests the possibility of using such a conversion and excitation mechanism to replicate the functioning of cardiac conduction system. The chaotic analysis of the sinus node subjected to a sinusoidal type disturbance (E 0sin(ωt)) is also presented, it shows that in its chaotic state, the nodes of the heart, as well as the ECG, provide very high frequency signals. This requires the control of the sinus node (natural pacemaker) in such a situation

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Skeletal Muscle–Specific Myosin Binding Protein-H Is Expressed in Purkinje Fibers of the Cardiac Conduction System

Circulation Research ◽

10.1161/01.res.80.5.665 ◽

1997 ◽

Vol 80 (5) ◽

pp. 665-672 ◽

Cited By ~ 23

Author(s):

Tatiana Alyonycheva ◽

Leona Cohen-Gould ◽

Christiana Siewert ◽

Donald A. Fischman ◽

Takashi Mikawa

Keyword(s):

Skeletal Muscle ◽

Binding Protein ◽

Conduction System ◽

Cardiac Conduction ◽

Cardiac Conduction System ◽

Purkinje Fibers ◽

Myosin Binding Protein ◽

Myosin Binding

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Distribution and Structure of Purkinje Fibers in the Heart of Ostrich (Struthio camelus) with the Special References on the Ultrastructure

International Journal of Zoology ◽

10.1155/2013/293643 ◽

2013 ◽

Vol 2013 ◽

pp. 1-6 ◽

Cited By ~ 2

Author(s):

Paria Parto ◽

Mina Tadjalli ◽

S. Reza Ghazi ◽

Mohammad Ali Salamat

Keyword(s):

Light And Electron Microscopy ◽

Great Part ◽

Conduction System ◽

Point Of View ◽

Cardiac Conduction ◽

Cardiac Conduction System ◽

Purkinje Fibers ◽

Thin Ring ◽

T Tubules ◽

P Cells

Purkinje fibers or Purkinje cardiomyocytes are part of the whole complex of the cardiac conduction system, which is today classified as specific heart muscle tissue responsible for the generation of the heart impulses. From the point of view of their distribution, structure and ultrastructural composition of the cardiac conduction system in the ostrich heart were studied by light and electron microscopy. These cells were distributed in cardiac conducting system including SA node, AV node, His bundle and branches as well as endocardium, pericardium, myocardium around the coronary arteries, moderator bands, white fibrous sheet in right atrium, and left septal attachment of AV valve. The great part of the Purkinje fiber is composed of clear, structure less sarcoplasm, and the myofibrils tend to be confined to a thin ring around the periphery of the cells. They have one or more large nuclei centrally located within the fiber. Ultrastructurally, they are easily distinguished. The main distinction feature is the lack of electron density and having a light appearance, due to the absence of organized myofibrils. P-cells usually have two nuclei with a mass of short, delicate microfilaments scattered randomly in the cytoplasm; they contain short sarcomeres and myofibrillar insertion plaque. They do not have T-tubules.

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