Search results for "Digitoxin"
showing 10 items of 15 documents
Dose-response relationships and plasma concentrations of digitalis glycosides in man.
1978
An inter-individual, randomized, double-blind study of digitoxin (Dt) and β-acetyl digoxin (D) was performed in 120 healthy male volunteers. Groups of 10 persons each received orally D 0, 0.1, 0.2, 0.3, 0.4, 0.5 or 0.6 mg and Dt 0.04, 0.08, 0.12, or 0.16 mg daily for 7 days; Loading doses were given for the first three days. Plasma levels were measured with an86Rb-erythrocyte assay 24 h after the last dose. ECG, carotid artery pulse and phonocardiogram were recorded prior to (b) and 24 h after (a) the last dose. QTc, amplitude of T-waves in V2 to V6, electromechanical systole (QS2c) and left ventricular ejection time (LVETc) were measured. The differences between a and b (Δ-values) reflect …
The effect of cathartic agents on transmucosal electrical potential difference in the human rectum.
1980
Active ion transport in the colon is generating a transmucosal electrical potential difference (PD) of about 40 mV. Cathartic agents inhibit electrolyte and water net-absorption or cause net-secretion which should be reflected in a change of PD. In 83 normal subjects the effect of an isotonic eletrolyte solution (control) and different cathartic agents on rectal PD was tested: Laxatives (bisacodyl, rhein), bile acids (cholic and deoxycholic acid), fatty acids (oleic and ricinoleic acid) and cardiac glycosides (meproscillarin, digitoxin, digoxin). Bisacodyl, deoxycholic acid in high concentration, meproscillarin and digitoxin significantly decreased PD, while the other substances did not. Ca…
Azapropazone binding to human serum albumin
1980
Azapropazone, a new non-steroidal antiinflammatory drug, is strongly bound to human serum albumin. As revealed by Scatchard analysis, one high-affinity binding site with an association constant of about 1.2 x 10(6)M-1 and two low-affinity binding sites with association constants of about 0.05 x 10(6)M-1 were found. While the high-affinity binding site of azapropazone is clearly not identical with the diazepam or digitoxin binding sites of human serum albumin, contradictory evidence was found by optical measurements and displacement studies for the similarity of the azapropazone and the warfarin binding site of human serum albumin. At present, it is suggested that both drugs bind to differen…
Induction of digoxin-like material production, and the digoxin binding in the unicellular organism Tetrahymena by digitoxin.
1998
Thin layer chromatographic, and laser-confocal microscopic analyses with a monoclonal antibody to digoxin also displaying high affinity to digoxigenin, were used to determine the presence and localization of cardioactive glycosides. Tetrahymena pyriformis was found to possess digitoxigenin-like material, but digoxin, digitoxin, digoxigenin, gitoxin and lanatoside C were not detected. Digitoxin treatment elicited the appearance of a digoxin-like material in the progeny generations. Digoxin was taken up by untreated Tetrahymena, especially strongly 24 h after digitoxin treatment. While the cardenolide was localized in vesicles of the cell body in untreated Tetrahymena, the engulfed digoxin ap…
Digoxin and digitoxin elimination in man by charcoal hemoperfusion
1978
Since there is no widely used causal means of reducing the severity of massive digitalis intoxication the capability of hemoperfusion with coated activated charcoal to remove toxicologically relevant amounts of digoxin and digitoxin was evaluated in vitro and in man. At a blood flow rate of 100 ml/min the digoxin clearance by hemoperfusion in vitro was 51±8 ml/min in comparison to 24.3±11.3 ml/min by hemodialysis. The average hemoperfusion clearance of digitoxin was 31.7±13.4 ml/min, whereas almost no digitoxin was removed by hemodialysis. These clearance values point to the ability of hemoperfusion of eliminating digitalis glycosides from the blood. They do not clarify the essential questi…
Vergleich der subcellulären Verteilung von 3H-Strophanthin und 3H-Digi-toxin im Meerschweinchenherzen / Comparison of the Subcellular Distribution of…
1969
Um Aufschlus uber den Wirkort von Herzglykosiden in der Herzmuskelzelle zu erhalten, wurde die subcellulare Verteilung von 3H-Digitoxin und 3H-Strophanthin untersucht und mit dem positiv inotropen Effekt verglichen. Meerschweinchenherzen wurden nach der Langendorff-Methode mit glykosidhaltiger Tyrodelosung (3 · 10−7 bzw. 2,8 · 10−7 g/ml; 37°C) perfundiert; die Kontraktionskraft wurde fortlaufend isotonisch registriert. Die Glykosidkonzentration in den einzelnen Fraktionen wurde nach Homogenisation, Differentialzentrifugation und Extraktion der Glykoside mit Toluol bzw. Dioxan mit einem Flussigkeitsszintillations-zahlgerat bestimmt. Die Ruckverteilung wahrend der Aufarbeitung wurde in Kontro…
Über eine Nebenwirkung von Herzglykosiden auf die Viskosität des Blutes
1964
Die Strukturviskositat und Thixotropie von menschlichem Blut wird durch zugesetzte Herzglykoside (k-Strophanthin, Digitoxin) erniedrigt. Dieses Phanomen unterstutzt die Wirkung der Herzglykoside am Herzen.
Interspecies differences in cancer susceptibility and toxicity.
1999
One of the most complex challenges to the toxicologist represents extrapolation from laboratory animals to humans. In this article, we review interspecies differences in metabolism and toxicity of heterocyclic amines, aflatoxin B1, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), and related compounds, endocrine disrupters, polycyclic aromatic hydrocarbons, tamoxifen, and digitoxin. As far as possible, extrapolations to human toxicity and carcinogenicity are performed. Humans may be more susceptible to the carcinogenic effect of heterocyclic amines than monkeys, rats, and mice. Especially, individuals with high CYP1A2 and 3A4 activities and the rapid acetylator phenotype may be expected to have …
An economical hemoperfusion system to determine in vitro clearances of various poisons with different adsorbents.
1980
An economical hemoperfusion system for clearance studies in vitro was developped. It was ascertained, that hemoperfusion using columns which contain 13 g of adsorbent and perfused at a blood flow rate of 1.25 ml/min results in the same relative clearances as when using clinical sized columns containing 300–355 g of the absorbent and run at 100 ml/min. The adsorption kinetics of toxicologically important drugs and pesticides are given as examples. To date 27 substances were tested systematically. The investigation has shown, that no adsorbent is without exception the best one, but the efficacy can vary from substance to substance.
Isoform specificity of cardiac glycosides binding to human Na+,K+-ATPase α1β1, α2β1 and α3β1
2009
Abstract Cardiac glycosides inhibit the Na + ,K + -ATPase and are used for the treatment of symptomatic heart failure and atrial fibrillation. In human heart three isoforms of Na + ,K + -ATPase are expressed: α 1 β 1 , α 2 β 1 and α 3 β 1 . It is unknown, if clinically used cardiac glycosides differ in isoform specific affinities, and if the isoforms have specific subcellular localization in human cardiac myocytes. Human Na + ,K + -ATPase isoforms α 1 β 1 , α 2 β 1 and α 3 β 1 were expressed in yeast which has no endogenous Na + ,K + -ATPase. Isoform specific affinities of digoxin, digitoxin, β-acetyldigoxin, methyldigoxin and ouabain were assessed in [³H]-ouabain binding assays in the abse…