Biomaterial Database

Spontaneous action potentials of cells in the canine sinus node. 1976

W T Woods, and F Urthaler, and T N James

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.

UI	MeSH Term	Description	Entries
D008564	Membrane Potentials	The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).	Resting Potentials,Transmembrane Potentials,Delta Psi,Resting Membrane Potential,Transmembrane Electrical Potential Difference,Transmembrane Potential Difference,Difference, Transmembrane Potential,Differences, Transmembrane Potential,Membrane Potential,Membrane Potential, Resting,Membrane Potentials, Resting,Potential Difference, Transmembrane,Potential Differences, Transmembrane,Potential, Membrane,Potential, Resting,Potential, Transmembrane,Potentials, Membrane,Potentials, Resting,Potentials, Transmembrane,Resting Membrane Potentials,Resting Potential,Transmembrane Potential,Transmembrane Potential Differences
D010477	Perfusion	Treatment process involving the injection of fluid into an organ or tissue.	Perfusions
D004285	Dogs	The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)	Canis familiaris,Dog
D004594	Electrophysiology	The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.
D000200	Action Potentials	Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.	Spike Potentials,Nerve Impulses,Action Potential,Impulse, Nerve,Impulses, Nerve,Nerve Impulse,Potential, Action,Potential, Spike,Potentials, Action,Potentials, Spike,Spike Potential
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012849	Sinoatrial Node	The small mass of modified cardiac muscle fibers located at the junction of the superior vena cava (VENA CAVA, SUPERIOR) and right atrium. Contraction impulses probably start in this node, spread over the atrium (HEART ATRIUM) and are then transmitted by the atrioventricular bundle (BUNDLE OF HIS) to the ventricle (HEART VENTRICLE).	Sinuatrial Node,Sinus Node,Sino-Atrial Node,Sinu-Atrial Node,Node, Sino-Atrial,Node, Sinoatrial,Node, Sinu-Atrial,Node, Sinuatrial,Node, Sinus,Nodes, Sino-Atrial,Nodes, Sinoatrial,Nodes, Sinu-Atrial,Nodes, Sinuatrial,Nodes, Sinus,Sino Atrial Node,Sino-Atrial Nodes,Sinoatrial Nodes,Sinu Atrial Node,Sinu-Atrial Nodes,Sinuatrial Nodes,Sinus Nodes