Biomaterial Database

Gram-negative endotoxemia: effects on cardiac Na-Ca exchange and stoichiometry. 1989

C C Hale, and J A Allert, and R S Keller, and H R Adams, and J L Parker

Department of Veterinary Biomedical Sciences, University of Missouri, Columbia 65211.

We studied the acute effects of gram-negative endotoxemia on Na-Ca exchange activity and stoichiometry in cardiac sarcolemmal (SL) vesicles isolated from pentobarbital-anesthetized dogs. Dogs were given either endotoxin (ET; 1.5 mg/kg IV) or saline vehicle (C; n = 4 dogs/group). Characteristic of endotoxemia, endotoxin produced a decrease in mean arterial pressure from 120 to 60 mmHg, an increase in packed cell volume from 38% to 60%, and an increase in heart rate from 130 to 190 bpm. After 2 hr, hearts were removed and SL vesicles were prepared from left and right ventricular tissue. For ET and C, Na-dependent Ca2+ uptake (left ventricle) was 3.13 and 3.44 (2 sec) and 18.60 and 19.42 (60 sec) nmole Ca2+/mg protein, respectively; ET group values were not significantly different from corresponding C values in either left or right ventricles. The stoichiometry of Na-Ca exchange was determined in left ventricular vesicles by a previously described thermodynamic approach utilizing a K+-valinomycin gradient opposed by Na+ equilibrium potentials (Reeves and Hale: J Biol Chem 259:7733-7739, 1984). The stoichiometry of exchange of Na+ for Ca2+ was 2.84 +/- 0.09 and 2.74 +/- 0.14 for ET and C, respectively. We conclude that during the developmental phase (2 hr) of endotoxemia, there were no ET-mediated changes in cardiac Na-Ca exchange activity in SL vesicles from either left or right ventricular tissue and the exchange process remained electrogenic with a stoichiometry of 3Na+ for 1Ca2+.

UI	MeSH Term	Description	Entries
D007474	Ion Exchange	Reversible chemical reaction between a solid, often one of the ION EXCHANGE RESINS, and a fluid whereby ions may be exchanged from one substance to another. This technique is used in water purification, in research, and in industry.	Exchange, Ion
D009206	Myocardium	The muscle tissue of the HEART. It is composed of striated, involuntary muscle cells (MYOCYTES, CARDIAC) connected to form the contractile pump to generate blood flow.	Muscle, Cardiac,Muscle, Heart,Cardiac Muscle,Myocardia,Cardiac Muscles,Heart Muscle,Heart Muscles,Muscles, Cardiac,Muscles, Heart
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
D002621	Chemistry	A basic science concerned with the composition, structure, and properties of matter; and the reactions that occur between substances and the associated energy exchange.
D004285	Dogs	The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)	Canis familiaris,Dog
D004731	Endotoxins	Toxins closely associated with the living cytoplasm or cell wall of certain microorganisms, which do not readily diffuse into the culture medium, but are released upon lysis of the cells.	Endotoxin
D004927	Escherichia coli Infections	Infections with bacteria of the species ESCHERICHIA COLI.	E coli Infections,E. coli Infection,Infections, E coli,Infections, Escherichia coli,E coli Infection,E. coli Infections,Escherichia coli Infection,Infection, E coli,Infection, E. coli,Infection, Escherichia coli
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
D012508	Sarcolemma	The excitable plasma membrane of a muscle cell. (Glick, Glossary of Biochemistry and Molecular Biology, 1990)	Sarcolemmas
D012772	Shock, Septic	Sepsis associated with HYPOTENSION or hypoperfusion despite adequate fluid resuscitation. Perfusion abnormalities may include but are not limited to LACTIC ACIDOSIS; OLIGURIA; or acute alteration in mental status.	Endotoxin Shock,Septic Shock,Shock, Endotoxic,Shock, Toxic,Toxic Shock,Toxic Shock Syndrome,Endotoxin Shocks,Shock Syndrome, Toxic,Shock, Endotoxin,Shocks, Endotoxin,Toxic Shock Syndromes