Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “CARDIAC GLYCOSIDES”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 631 records · Page 35Linked to original sources
PubMed1975

Cardiac glycoside receptor in potassium depletion.

Ouabain binding capacity of cell membranes is directly related to (Na+ + K+)-ATPase activity. The extent of ouabain inhibition of (Na+ + K+)-ATPase is a measure of ouabain receptor sites occupied. Dissociation constants of the ouabain-receptor complexes are identical in all organs in a single species but vary among different species. K+ decreases the association rate constant of the ouabain receptor interaction without altering the dissociation rate constants. Titration of digoxin-inhibited (Na+ + K+)-ATPase from guinea pig heart with digoxin antibodies shows a reversal of the inhibition at lower antibody concentrations in the presence of K+ than in the absence of K+. It is concluded that digitalis intolerance in acute hypokalemia reflects the increased affinity of the cardiac glycoside receptor under these conditions.

Adenosine Triphosphatases↗
PubMed2000

A novel high-pressure liquid-liquid extraction process for downstream processing in biotechnology: extraction of cardiac glycosides.

This investigation examines phase equilibrium phenomena that can be used to create two water-like solvents for liquid-liquid extraction in downstream processing in biotechnology: a completely miscible, binary liquid mixture of water and a hydrophilic organic solvent (e. g., an alcohol) reveals a liquid phase split, when it is pressurized with a "near-critical" gas (i.e., a substance which at ambient conditions is a gas, near its critical temperature). This phase split results in two hydrophilic liquid phases. Making use of this phenomenon in process development first requires research on the phase split phenomenon and, second, research on the feasibility of biomolecule extraction and separation. In this study, basic fluid phase equilibrium phenomena are briefly described. Then, experimental results are reported for the partitioning of small amounts of cardiac glycosides (digitoxin and digoxin) on coexisting liquid phases in the high-pressure, three-phase, vapor-liquid-liquid equilibrium of the ternary system of "near critical" CO(2) + water + 1-propanol, at 313 K and 333 K. Finally, a process for extraction and separation of the aforementioned glycosides by means of the high-pressure phase equilibrium phenomenon is discussed.

1-Propanol↗
PubMed1998

Stereoselective inhibition by the diastereomers quinidine and quinine of uptake of cardiac glycosides into isolated rat hepatocytes.

The pharmacokinetic interaction between quinidine and digoxin in patients is well-known, in general requiring a dose reduction of digoxin in patients concomitantly treated with quinidine. Quinine, the diastereomer of quinidine, has not been as extensively studied in this respect. In addition to an interaction with the renal clearance of digoxin by quinidine, both diastereomers have been reported to inhibit the biliary clearance of digoxin in man. To further investigate the mechanisms of these hepatobiliary transport interactions at the cellular level, we compared the effects of quinidine and quinine, as well as of the calcium antagonist verapamil, on the uptake of digoxin and ouabain in isolated rat hepatocytes. Initial uptake rates of digoxin and ouabain were determined in the presence of various concentrations of quinine and quinidine. A concentration dependent inhibition of the cellular uptake of both cardiac glycosides by quinine and quinidine was found, quinine being a more potent inhibitor than quinidine. Our results indicate a stereoselective inhibition of the hepatocellular uptake by the two diastereomers quinidine and quinine, the latter being about equipotent to verapamil. This unequal inhibitory potency of the two basic drugs was detected earlier in oocyte studies with the cloned organic cation transporter OCT1.

Animals↗