Biomaterial Database

Membrane currents and tension in cat ventricular muscle treated with cardiac glycosides. 1975

T F McDonald, and H Nawrath, and W Trautwein

The effect of cardiac glycosides on membrane currents and tension in cat ventricular muscle was studied using the single sucrose gap voltage clamp method. Complete tension-voltage and current-voltage relations were obtained in five preparations before and during treatment with dihydro-ouabain (DHO, 1.7 X 10(-5)M). After 1-2 minutes of DHO, the developed tension was 15% greater than control, but there was no change in either the slow inward (calcium) current (Ica) or the level of the outward current flowing at the end of a 300-msec depolarization (Iout). After 6-8 minutes of DHO, there was a 60% increase in developed tension, a noticeable increase in resting tension, a 20% decrease in Ica, and a smaller increase in Iout. It seems possible that the reduction of Ica was due to a reduced driving force. In preparations treated with ouabain (5 X 10(-7)M, 3-5 minutes), developed tension was 45-150% greater than control with no change in Ica or Iout between -45 and + 15 mv. We conclude that the inotropic action of these cardiac glycosides is not mediated by an increase in Ica.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D010042	Ouabain	A cardioactive glycoside consisting of rhamnose and ouabagenin, obtained from the seeds of Strophanthus gratus and other plants of the Apocynaceae; used like DIGITALIS. It is commonly used in cell biological studies as an inhibitor of the NA(+)-K(+)-EXCHANGING ATPASE.	Acocantherin,G-Strophanthin,Acolongifloroside K,G Strophanthin
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
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
D002462	Cell Membrane	The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.	Plasma Membrane,Cytoplasmic Membrane,Cell Membranes,Cytoplasmic Membranes,Membrane, Cell,Membrane, Cytoplasmic,Membrane, Plasma,Membranes, Cell,Membranes, Cytoplasmic,Membranes, Plasma,Plasma Membranes
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.
D005260	Female		Females
D006321	Heart	The hollow, muscular organ that maintains the circulation of the blood.	Hearts
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
D013314	Stress, Mechanical	A purely physical condition which exists within any material because of strain or deformation by external forces or by non-uniform thermal expansion; expressed quantitatively in units of force per unit area.	Mechanical Stress,Mechanical Stresses,Stresses, Mechanical