Biomaterial Database

Calcium currents in normal and hypertrophied isolated feline ventricular myocytes. 1988

R B Kleiman, and S R Houser

Department of Physiology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140.

The magnitude and kinetics of the slow inward calcium current (Isi) were compared in single right ventricular myocytes that were isolated from normal cats and cats with right ventricular hypertrophy. Peak inward current density was greater in hypertrophy than normal myocytes (-20.4 +/- 15.3 vs. -10.4 +/- 8.8 microA/cm2, P less than 0.05). When we blocked early outward currents with intracellular CsCl, however, the peak magnitude of Isi was shown to be similar in hypertrophy and normal myocytes (-16.4 +/- 11.2 vs. -12.7 +/- 3.0 microA/cm2, P = NS). The increased net inward current in hypertrophy was thus due to a decrease in Cs-sensitive early outward current rather than an increase in the magnitude of Isi. The fast component of inactivation of Isi was similar in hypertrophy and normal myocytes, but the slow component was delayed in hypertrophy (slow time constant; tau slow = 75.9 +/- 14.7 ms vs. tau slow = 60.6 +/- 4.9 ms, P less than 0.05). These abnormalities of Isi may contribute to the prolonged duration of the action potential and of contraction in hypertrophied myocardium, but a defect in excitation-contraction coupling distal to Isi appears to produce the diminished magnitude of contraction.

UI	MeSH Term	Description	Entries
D012016	Reference Values	The range or frequency distribution of a measurement in a population (of organisms, organs or things) that has not been selected for the presence of disease or abnormality.	Normal Range,Normal Values,Reference Ranges,Normal Ranges,Normal Value,Range, Normal,Range, Reference,Ranges, Normal,Ranges, Reference,Reference Range,Reference Value,Value, Normal,Value, Reference,Values, Normal,Values, Reference
D002415	Cats	The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)	Felis catus,Felis domesticus,Domestic Cats,Felis domestica,Felis sylvestris catus,Cat,Cat, Domestic,Cats, Domestic,Domestic Cat
D002586	Cesium	A member of the alkali metals. It has an atomic symbol Cs, atomic number 55, and atomic weight 132.91. Cesium has many industrial applications, including the construction of atomic clocks based on its atomic vibrational frequency.	Caesium,Caesium-133,Cesium-133,Caesium 133,Cesium 133
D002712	Chlorides	Inorganic compounds derived from hydrochloric acid that contain the Cl- ion.	Chloride,Chloride Ion Level,Ion Level, Chloride,Level, Chloride Ion
D004553	Electric Conductivity	The ability of a substrate to allow the passage of ELECTRONS.	Electrical Conductivity,Conductivity, Electric,Conductivity, Electrical
D006321	Heart	The hollow, muscular organ that maintains the circulation of the blood.	Hearts
D006332	Cardiomegaly	Enlargement of the HEART, usually indicated by a cardiothoracic ratio above 0.50. Heart enlargement may involve the right, the left, or both HEART VENTRICLES or HEART ATRIA. Cardiomegaly is a nonspecific symptom seen in patients with chronic systolic heart failure (HEART FAILURE) or several forms of CARDIOMYOPATHIES.	Cardiac Hypertrophy,Enlarged Heart,Heart Hypertrophy,Heart Enlargement,Cardiac Hypertrophies,Enlargement, Heart,Heart Hypertrophies,Heart, Enlarged,Hypertrophies, Cardiac,Hypertrophies, Heart,Hypertrophy, Cardiac,Hypertrophy, Heart
D006352	Heart Ventricles	The lower right and left chambers of the heart. The right ventricle pumps venous BLOOD into the LUNGS and the left ventricle pumps oxygenated blood into the systemic arterial circulation.	Cardiac Ventricle,Cardiac Ventricles,Heart Ventricle,Left Ventricle,Right Ventricle,Left Ventricles,Right Ventricles,Ventricle, Cardiac,Ventricle, Heart,Ventricle, Left,Ventricle, Right,Ventricles, Cardiac,Ventricles, Heart,Ventricles, Left,Ventricles, Right
D006439	Hemodynamics	The movement and the forces involved in the movement of the blood through the CARDIOVASCULAR SYSTEM.	Hemodynamic
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