Biomaterial Database

The effect of thapsigargin on sarcoplasmic reticulum Ca2+ content and contractions of single myocytes of rat ventricular myocardium. 1993

B Lewartowski, and B Wolska

Department of Clinical Physiology, Medical Centre of Postgraduate Education, Warsaw, Poland.

The effect of Thapsigargin (TG) shown to block selectively the Ca(2+)-ATPase of sarcoplasmic reticulum (SR) on the SR Ca2+ content and contractions of single rat cadiomyocytes was investigated. In 80% of cells 10(-6) M TG blocked Ca2+ uptake by SR at rest, depleted the SR Ca2+, inhibited postrest potentiation and changed the pattern of response to premature contractions. Amplitude of steady state contractions was reduced to 11 +/- 4% of pre-TG control. In 20% of cells TG had similar effect on the SR function, however, amplitude of contractions was reduced to only 50 +/- 7% of control. It is concluded that the results obtained in 80% of the cells are compatible with the wide-spread notion that contractions of rat cardiac myocytes are activated predominantly by Ca2+ released from SR. However, population of myocytes of ventricular myocardium of this species is not homogeneous in this respect. In 20% of them contractions are activated by both sarcolemmal and SR Ca2+ contribution being approximately equal. These cells occupy intermediate position between guinea-pig cells and the bulk of rat cells.

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
D010936	Plant Extracts	Concentrated pharmaceutical preparations of plants obtained by removing active constituents with a suitable solvent, which is evaporated away, and adjusting the residue to a prescribed standard.	Herbal Medicines,Plant Extract,Extract, Plant,Extracts, Plant,Medicines, Herbal
D010946	Plants, Medicinal	Plants whose roots, leaves, seeds, bark, or other constituent parts possess therapeutic, tonic, purgative, curative or other pharmacologic attributes, when administered to man or animals.	Herbs, Medicinal,Medicinal Herbs,Healing Plants,Medicinal Plants,Pharmaceutical Plants,Healing Plant,Herb, Medicinal,Medicinal Herb,Medicinal Plant,Pharmaceutical Plant,Plant, Healing,Plant, Medicinal,Plant, Pharmaceutical,Plants, Healing,Plants, Pharmaceutical
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
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
D006636	Histamine Release	The secretion of histamine from mast cell and basophil granules by exocytosis. This can be initiated by a number of factors, all of which involve binding of IgE, cross-linked by antigen, to the mast cell or basophil's Fc receptors. Once released, histamine binds to a number of different target cell receptors and exerts a wide variety of effects.	Histamine Liberation,Histamine Liberations,Histamine Releases
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
D013729	Terpenes	A class of compounds composed of repeating 5-carbon units of HEMITERPENES.	Isoprenoid,Terpene,Terpenoid,Isoprenoids,Terpenoids
D051381	Rats	The common name for the genus Rattus.	Rattus,Rats, Laboratory,Rats, Norway,Rattus norvegicus,Laboratory Rat,Laboratory Rats,Norway Rat,Norway Rats,Rat,Rat, Laboratory,Rat, Norway,norvegicus, Rattus