Conduction velocity and gap junction resistance in hypertrophied, hypoxic guinea-pig left ventricular myocardium. 1998

M Cooklin, and W R Wallis, and D J Sheridan, and C H Fry
Academic Cardiology Unit, Division of the National Heart and Lung Institute, Imperial College School of Medicine, St Mary's Hospital, South Wharf Road, London W2 1NY, UK.

The passive and active electrical properties of left ventricular myocardium were measured, using conducted action potentials and current clamp of isolated myocytes. The objective was to quantify changes of intracellular resistivity, Ri, during hypertrophic growth and the simultaneous imposition of cellular hypoxia. Ri was estimated from the time course of the rising phase of a conducted action potential using a solution of the two-dimensional cable equation. The thoracic aorta of guinea-pigs was constricted to induce left ventricular hypertrophy (LVH) and myocardium used 50 and 150 days post-operation. Conduction velocity increased in the earlier stage of LVH and declined in the later stage, compared with age-matched controls. Hypoxia reduced conduction velocity in all experimental groups. Ri increased only in the later stage of hypertrophy (253 +/- 39 Omega cm to 544 +/- 130 Omega cm) and was additionally increased by hypoxia in all groups (e.g. control myocardium 252 +/- 39 Omega cm to 506 +/- 170 Omega cm). The magnitude of the increase of Ri in hypertrophied, hypoxic myocardium can create conditions required to generate re-entrant arrhythmias.

UI MeSH Term Description Entries
D008839 Microelectrodes Electrodes with an extremely small tip, used in a voltage clamp or other apparatus to stimulate or record bioelectric potentials of single cells intracellularly or extracellularly. (Dorland, 28th ed) Electrodes, Miniaturized,Electrode, Miniaturized,Microelectrode,Miniaturized Electrode,Miniaturized Electrodes
D009119 Muscle Contraction A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments. Inotropism,Muscular Contraction,Contraction, Muscle,Contraction, Muscular,Contractions, Muscle,Contractions, Muscular,Inotropisms,Muscle Contractions,Muscular Contractions
D009431 Neural Conduction The propagation of the NERVE IMPULSE along the nerve away from the site of an excitation stimulus. Nerve Conduction,Conduction, Nerve,Conduction, Neural,Conductions, Nerve,Conductions, Neural,Nerve Conductions,Neural Conductions
D006168 Guinea Pigs A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research. Cavia,Cavia porcellus,Guinea Pig,Pig, Guinea,Pigs, Guinea
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
D000465 Algorithms A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task. Algorithm
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
D000860 Hypoxia Sub-optimal OXYGEN levels in the ambient air of living organisms. Anoxia,Oxygen Deficiency,Anoxemia,Deficiency, Oxygen,Hypoxemia,Deficiencies, Oxygen,Oxygen Deficiencies
D001013 Aorta, Thoracic The portion of the descending aorta proceeding from the arch of the aorta and extending to the DIAPHRAGM, eventually connecting to the ABDOMINAL AORTA. Aorta, Ascending,Aorta, Descending,Aortic Arch,Aortic Root,Arch of the Aorta,Descending Aorta,Sinotubular Junction,Ascending Aorta,Thoracic Aorta,Aortic Roots,Arch, Aortic,Ascending Aortas,Junction, Sinotubular,Root, Aortic,Sinotubular Junctions
D017379 Hypertrophy, Left Ventricular Enlargement of the LEFT VENTRICLE of the heart. This increase in ventricular mass is attributed to sustained abnormal pressure or volume loads and is a contributor to cardiovascular morbidity and mortality. Left Ventricular Hypertrophy,Ventricular Hypertrophy, Left,Hypertrophies, Left Ventricular,Left Ventricular Hypertrophies,Ventricular Hypertrophies, Left

Related Publications

M Cooklin, and W R Wallis, and D J Sheridan, and C H Fry
August 1997, Journal of cardiovascular electrophysiology,
M Cooklin, and W R Wallis, and D J Sheridan, and C H Fry
April 1991, Cardiovascular research,
M Cooklin, and W R Wallis, and D J Sheridan, and C H Fry
July 2007, Anadolu kardiyoloji dergisi : AKD = the Anatolian journal of cardiology,
M Cooklin, and W R Wallis, and D J Sheridan, and C H Fry
December 1990, European journal of pharmacology,
M Cooklin, and W R Wallis, and D J Sheridan, and C H Fry
May 1993, Journal of clinical pharmacology,
M Cooklin, and W R Wallis, and D J Sheridan, and C H Fry
April 1990, British journal of pharmacology,
M Cooklin, and W R Wallis, and D J Sheridan, and C H Fry
December 2004, Experimental biology and medicine (Maywood, N.J.),
M Cooklin, and W R Wallis, and D J Sheridan, and C H Fry
April 2001, Pflugers Archiv : European journal of physiology,
M Cooklin, and W R Wallis, and D J Sheridan, and C H Fry
January 2012, American journal of physiology. Heart and circulatory physiology,
M Cooklin, and W R Wallis, and D J Sheridan, and C H Fry
December 2013, Circulation. Arrhythmia and electrophysiology,
Copied contents to your clipboard!