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Spontaneous action potentials of cells in the canine sinus node
- Source :
- Circulation Research. 39:76-82
- Publication Year :
- 1976
- Publisher :
- Ovid Technologies (Wolters Kluwer Health), 1976.
-
Abstract
- Right atria were excised from the hearts of 20 young dogs (15 +/- 5 weeks old) and maintained in vitro in order to perform microelectrode impalements. The atria contracted spontaneously for at least 6 hours at a stable rate of 127/min when they were perfused with Krebs-Ringer bicarbonate solution through the sinus node artery. Cells within a small area near the sinus node artery and between the superior vena cava and right atrium consistently yielded transmembrane potentials typical of pacemaker cells. This area was verified histologically to be the midportion of the sinus node. Electrical characteristics of these sinus node pacemaker cells were: maximum diastolic potential, -56 +/- 7 mV (mean +/- 1 SD); action potential amplitude, 56 +/- 8 mV; overshoot, 0 +/- 2 mV. Smooth transitions from phase 4 to phase 0 were always present. From these experiments we conclude that the excised perfused canine right atrium provides a useful new experimental cardiac preparation because it maintains stable spontaneous activity for many hours in vitro and the sinus node within it is readily accessible for study by intracellular microelectrodes.
- Subjects :
- medicine.medical_specialty
Physiology
Diastole
Action Potentials
Membrane Potentials
Dogs
Superior vena cava
Internal medicine
medicine
Animals
Sinus (anatomy)
Sinoatrial Node
Sinus Node Artery
business.industry
Anatomy
Electrophysiology
Perfusion
Microelectrode
medicine.anatomical_structure
cardiovascular system
Cardiology
Right atrium
Node (circuits)
Cardiology and Cardiovascular Medicine
business
Intracellular microelectrodes
Subjects
Details
- ISSN :
- 15244571 and 00097330
- Volume :
- 39
- Database :
- OpenAIRE
- Journal :
- Circulation Research
- Accession number :
- edsair.doi.dedup.....b3e509ad968e2d31e5f3721665c69455