Biomaterial Database

Elementary events in excitation-contraction coupling of the mammalian myocardium. 1977

H Antoni

Excitation-contraction coupling of the mammalian myocardium is widely assumed to comprise the following chain of events: (1) Influx of Ca++ into the cell during the plateau phase of the action potential as well as Ca++ release from the subsarcolemmal cisternae of sarcoplasmic reticulum. (2) Activation of the contractile proteins by interaction of Ca++ with the troponin-tropomyosin system. (3) Relaxation due to reuptake of Ca++ by the sarcotubular system as well as by pumping of Ca++ out of the cell through the surface membrane and the transverse tubular system. (4) Movement of Ca++ in the longitudinal tubules back to the subsarcolemmal cisternae. A short comment is included about the effects of hypertrophy on the excitatory processes as well as on cellular structural constituents directly involved in excitation-contraction coupling.

UI	MeSH Term	Description	Entries
D009200	Myocardial Contraction	Contractile activity of the MYOCARDIUM.	Heart Contractility,Inotropism, Cardiac,Cardiac Inotropism,Cardiac Inotropisms,Contractilities, Heart,Contractility, Heart,Contraction, Myocardial,Contractions, Myocardial,Heart Contractilities,Inotropisms, Cardiac,Myocardial Contractions
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D006329	Heart Conduction System	An impulse-conducting system composed of modified cardiac muscle, having the power of spontaneous rhythmicity and conduction more highly developed than the rest of the heart.	Conduction System, Heart,Conduction Systems, Heart,Heart Conduction Systems,System, Heart Conduction,Systems, Heart Conduction
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
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
D012519	Sarcoplasmic Reticulum	A network of tubules and sacs in the cytoplasm of SKELETAL MUSCLE FIBERS that assist with muscle contraction and relaxation by releasing and storing calcium ions.	Reticulum, Sarcoplasmic,Reticulums, Sarcoplasmic,Sarcoplasmic Reticulums
D014335	Tropomyosin	A protein found in the thin filaments of muscle fibers. It inhibits contraction of the muscle unless its position is modified by TROPONIN.	Paramyosin,Miniparamyosin,Paratropomyosin,Tropomyosin Mg,alpha-Tropomyosin,beta-Tropomyosin,gamma-Tropomyosin,Mg, Tropomyosin,alpha Tropomyosin,beta Tropomyosin,gamma Tropomyosin
D014336	Troponin	One of the minor protein components of skeletal and cardiac muscles. It functions as the calcium-binding component in a complex with BETA-TROPOMYOSIN; ACTIN; and MYOSIN and confers calcium sensitivity to the cross-linked actin and myosin filaments. Troponin itself is a complex of three regulatory proteins (TROPONIN C; TROPONIN I; and TROPONIN T).	Troponin Complex,Troponins