Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “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 829 records · Page 46Linked to original sources

Hypothesis on the role of hydroxylysyl glycosides in collagen fibre organization.

Hydroxylysine (Hyl) glycosides were determined both on the collagen produced by in-vitro cultures of human skin fibroblasts and pig articular chondrocytes and on the insoluble collagen extracted from bovine cornea and sclera. The disorganized collagen present in the culture medium showed a Hyl di- to mono-glycoside ratio markedly higher than the molecules extracted from the cell layer, where electron microscopy investigations demonstrated the real presence of collagen fibres. Moreover in bovine cornea the insoluble collagen showed a ratio Hyl di- to mono-glycoside significantly higher than in sclera, which, on the contrary, possesses fibres with larger mean diameter. The possible conversion of Hyl diglycoside to monoglycoside was suggested by the demonstration of an alpha (1----2) glucosidase activity on Hyl diglycoside , in an enzyme extract from cultured human skin fibroblasts. A role for the processes of collagen glycosylation and deglycosylation was thus considered.

Animals↗

[Gitoformate and digitoxin as alternatives to kidney-dependent glycosides in the therapy of cardiac insufficiency].

Kidney independent glycosides offer a high measure of therapeutic safety in comparison with kidney dependent glycosides. The intoxication rate lies between 4 and 6%. The pharmacokinetic properties of pentaformylgitoxin (INN: gitoformate) are comparable with those for digitoxin. The active glycoside 16-formylgitoxin (INN: gitaloxin) is formed by rapid deformylation of the formyl residue on the sugar chain. The maintenance dose of 0.06 mg daily, based on the half-life, produces therapeutic concentrations in the range 6-30 ng/ml. The required loading dose, as for digitoxin, amounts to 10 times the maintenance dose.

Cardiac Glycosides↗

[Indications and contraindications for therapy with cardiac glycosides].

Today glycosides have 3 indications: manifest and chronic cardiac insufficiency, arrhythmia absoluta and paroxysmal supraventricular tachycardia. Glycosides are no longer important in the therapy of acute cardiac insufficiency. There are also absolute and relative contraindications which should be recognized; in coronary heart disease glycosides should only be used if there is really a latent of manifest cardiac insufficiency.

Action Potentials↗

Cardenolide analogues. 11. Improved method for the use of Fétizon's reagent in the synthesis of cardiac glycosides.

An improved procedure has been developed for preparing glycosides of cardenolide genins. The method uses specially prepared Fétizon's reagent as catalyst, combined, in most cases, with mercuric cyanide and mercuric bromide. In the presence of this catalyst, genins react readily, at room temperature, with per-acetylated 1-bromo-sugars to give the acetylated glycosides in high yield with little or no side reaction. The reaction proceeds almost to completion in 30 to 60 min. The free glycoside is obtained by mild deacetylation using triethylamine/methanol/water (20:20:1) at room temperature for 72 h. Proof of structure was obtained using chemical ionization mass spectrometry, NMR spectroscopy and comparison of physical constants with published data. The compounds were tested for inotropic activity using the isolated guinea pig atrium.

Animals↗

[Changes in tumor cell sensitivity to the action of triterpene glycosides in liposomes].

The effect of the increased levels of cholesterol in ascites tumor cells of mouse sarcoma 37 on the cytochemical activity of 4 triterpene glycosides was studied. A definite correlation between the increase in the cholesterol level in the cells and the glycoside activity was noted. The effect character of some triterpene glycosides depended on the pH value of the medium.

Animals↗

Tissue binding sites involved in quinidine-cardiac glycoside interactions.

Quinidine has been shown to alter pharmacokinetics of digoxin by displacing the glycoside from mutual binding sites which are stereospecific with respect to quinidine. Characteristics of the binding site involved in quinidine-digoxin interaction were studied further in guinea pigs and rats. In the anesthetized rat quinidine significantly increased digoxin, but not digitoxin or ouabain, concentration in plasma during an i.v. infusion of a radiolabeled glycoside. In the anesthetized guinea pig, quinidine markedly increased plasma digoxin, but not digoxigenin or dihydrodigoxin, concentrations as estimated from a competitive binding assay using [3H]ouabain and a partially purified Na+, K+-adenosine triphosphatase preparation. Plasma sodium and potassium concentrations were not altered by quinidine either in control or digoxin-treated guinea pigs. In anesthetized guinea pigs, the quinidine concentrations in plasma was 6.4 +/- 1.1 muM after a 260-min fusion of quinidine at a rate of 26 mumol/kg/hr in control animals and 7.9 +/- 1.6 muM in those which were simultaneously infused with digoxin at a rate of 0.2 mumol/kg/hr. Antiarrhythmic agents, lidocaine, DL-propranolol or verapamil, did not cause a significant change in plasma digoxin concentration in the anesthetized guinea pigs. These results indicate that the binding site involved in quinidine-digoxin interaction has a strict structural requirement with respect ot the glycoside. Additionally, of the four antiarrhythmic drugs, quinidine appears to be the only agent which interacts with digoxin.

Animals↗

Cardiac glycosides and their metabolites levels in plasma and heart of guinea-pigs after I. V. administration.

One hr, 3 hr and 6 hr after i.v. injection of tritiated gitoxin, digoxin and digitoxin to the guinea-pig, the chloroform-insoluble metabolites, mainly conjugates known to be cardio-inactive, represent two thirds of the cardiac glycoside and metabolites content of plasma for gitoxin, half for digitoxin and one quarter for digoxin. Most of the compounds taken up by the myocardium are chloroform-soluble and may be considered as cardio-active. Considering the nature and proportions of the unchanged cardiac glycoside and its cardio-active metabolites in the myocardium of the guinea-pig, the cardiac effects that would be measured after administration of digoxin ar due to unchanged digoxin only; after administration of digitoxin, these effects are partly due to unchanged digitoxin but also to 12 beta-hydroxylated metabolites; after administration of gitoxin, besides unchanged gitoxin, the hydrolysis products of the sugar chain of gitoxin may contribute to the cardiac effects. The data obtained in plasma and in myocardium between 1 and 6 hr after administration of digoxin or gitoxin show that the distribution of the unchanged cardiac glycoside and each chloroform-soluble metabolite, from plasma to myocardium, is achieved 1 hr after administration. This situation does not occur with digitoxin and its metabolites.

Animals↗

[Composition and biological activity of steroid glycosides from a suspended culture of Dioscorea deltoidea Wall cells].

Two major steroid spirostanol glycosides (oligospirostanosides): deltoside (melting point, 296 degrees C, [alpha]D10:-90.8 degrees C (c 5.0,Py) and dioscine (melting point, 285-285 degrees C, [alpha]D10:-106.5 degrees C (c 5.0, Py) and a minor glycoside diosgenin-3-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranoside were isolated form cell suspensions of Discorea deltoidea after fermentation with beta-glucosidase. The cell suspensions contained these glycosides as the furostanol analogs (oligofurostanosides) deltoside, protodioscine, and delta 5-furosten-3 beta,22,26-triol-3-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D- glucopyranoside. The native oligofurostanosides isolated from D. deltoidea cell suspensions have a high biological activity and can be used as phytobiostimulators in medicine, veterinary, and agriculture.

Carbohydrate Sequence↗

Kinetic analysis of ouabain binding to native and mutated forms of Na,K-ATPase and identification of a new region involved in cardiac glycoside interactions.

Cardiac glycosides inhibit the Na,K-ATPase by binding to the catalytic alpha subunit of the enzyme. Site-directed mutagenesis of the H1-H2 domain has demonstrated the importance of this region in determining cardiac glycoside affinity. In this study, random mutagenesis was used to identify an amino acid, arginine 880, in the COOH-terminal portion of the alpha subunit which influences the sensitivity of the enzyme to ouabain. This residue is predicted to reside in the H7-H8 extracellular loop. Conversion of arginine 880 to a proline causes a 10-fold increase in the dissociation rate constant and a 2-fold increase in the association rate constant for [3H]ouabain binding. This results in an enzyme with a KD for ouabain 5-fold higher than the wild-type sheep alpha 1 isoform. These data are compatible with arginine 880 comprising a portion of the ouabain binding site. Furthermore, if arginine 880 is at the physical binding site, then this finding lends support to models that place this amino acid extracellularly since cardiac glycosides interact with the extracellular surface of the Na,K-ATPase. The ouabain binding characteristics of substitution R880P were compared with those of several different Na,K-ATPases, each of which contains a single amino acid substitution in the H1-H2 region of the alpha subunit. The substituted enzymes, C104A, Y108A, E116Q, P118K, and Y124F, vary considerably in their rates of dissociation (1-4-fold increase in the dissociation rate constant). In addition, the rate of association of [3H]ouabain binding to substitution P118K is 2-fold slower than that of the wild-type enzyme. These results suggest that the H1-H2 domain may participate directly in ouabain binding as well as be involved in conformational changes, both of which could affect the sensitivity of the enzyme to ouabain.

3T3 Cells↗

[Comparative study of the effect of cycloartane and cardiac glycosides on various parameters of myocardial metabolism in animals].

Administration of cycloartane (askendoside D-10 mg/kg, cyclosiversioside F-25 mg/kg) and heart glycosides (strophanthin K-0.36 mg/kg, celanide-1 mg/kg) for 3-10 days is found to exert unidirectional effect on the indices of carbon, lipid and adenine nucleotide metabolism in animal myocardium under study. Glycogen and ATP content increases under parallel decrease of lactate and nonesterified fatty acid content. Differences in the effect of cycloorthane and heart glycosides and especially on the indices of myocardial carbon metabolism were registered under more prolonged administration. Administration of heart glycosides in contrast to cycloorthane ones promotes a decrease of glycogen level and redox potential and increase of lactate content.

Adenosine Triphosphate↗

The stimulatory effect on human erythrocyte rubidium-86 uptake by anti-cardiac-glycoside antibodies.

Considerable, but as yet still controversial evidence indicates the presence, in mammalian tissues of endogenous digitalis-like factors (EDLFs) which inhibit cell membrane Na+, K(+)-adenosine triphosphatase (Na+, K(+)-ATPase) and which may cross-react with anti-digitalis antibodies. The aim of this study was to evaluate the effect of antibodies against cardiac glycosides on Na+, K(+)-ATPase in human erythrocytes. For this purpose, we measured the effect of antibodies against two different cardiac glycosides (anti-ouabain rabbit antiserum and anti-digoxin Fab fragments) on the activity of the Na+, K(+)-ATPase, as measured by erythrocyte rubidium-86 (86Rb) uptake, in subjects who had never come into contact with exogenous cardiac glycosides, and compared these results with the effect of two control rabbit sera: a normal serum and an antiserum to a non-related antigen. Anti-ouabain rabbit antiserum and anti-digoxin Fab fragments induced a significantly greater percentage change in 86Rb uptake in the erythrocytes than the two control sera (ANOVA followed by multiple comparison by the Games-Howell test). The average percentage change was +11.8 +/- 16.3% (n = 19) (mean +/- SD) for anti-ouabain antiserum +10.8 +/- 15.6% (n = 23) for anti-digoxin Fab fragments, -1.68 +/- 11.2% (n = 11) for anti-rhGM-CSF antiserum, and -5.8 +/- 11.7 (n = 10) for normal control serum. In a subgroup of ten subjects in whom the 3 antisera were tested simultaneously, the stimulation of erythrocyte 86Rb uptake induced by the two antidigitalis antibodies correlated significantly (r = 0.906, p = 0.001, n = 10).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[Action of triterpene glycosides of the dammarane series and their aglycones on the K+ and H+ ion currents in erythrocytes, induced by the ionophore A23187 and divalent ions].

The influence of the dammarane triterpene glycosides Rb1, Rb2, Rg1 and Rf and their aglycones 20(S) protopanaxatriol and 20(S) protopanaxadiol on fluctuation of the K+ and H+ flows in erythrocytes induced by ionophore A23187 and Ca2+ was studied. It was shown that glycoside Rb1 (10 to 50 micrograms/ml) and 20(S) protopanaxatriol (30 micrograms/ml) had a property of inducing fluctuation of the K+ and H+ flows in erythrocytes. In case of Rb1 the system entirely reversed to the initial state whereas in case of the protopanaxatriol use after the fluctuation the system did not reverse to the initial state. Glycosides Rb2 (10 to 30 micrograms/ml), Rg1 (5 to 20 micrograms/ml) and Rf (10 to 100 micrograms/ml) and 20(S) protopanaxadiol (30 micrograms/ml) in the concentrations used did not initiate the fluctuations. The above substances increased the extracellular concentration of K+ and pH without the system reversion to the initial state.

Animals↗

[Effect of triterpene glycosides on RNA biosynthesis in a yeast cell culture of Saccharomyces carlsbergensis].

The effect of triterpen glycosides of cauloside C from Caulophyllum robustum, theasaponine from Thea sinensis ahd stichoposide A from Stichopus japonicus on multiplication and biosynthesis of RNA in the cells of a 7-hour culture of Saccharomyces carlsbergensis was studied. It was shown that cauloside C, theasaponine and stichoposide A in concentrations of 7.5 gamma/ml inhibited multiplication of the yeast cells by 65, 10 and 90 per cent respectively. The summation RNA of the yeast cells is divided into 3 zones on Sephadex G-100. The glycosides induced no pronounced changes in the chromotographic profile of RNA. Biosynthesis of the transport and ribosomal RNA were inhibited to the same extent. Triterpen glycosides inhibited the biosynthesis of RNA at the stage of 14C-uridine in corporation into the nucleotide pool of the yeast cells.

Cells, Cultured↗

Effects of triterpenoid glycosides of the dammaran series and their aglycons on phase transitions of dipalmitoylphosphatidylcholine.

The effects of triterpenoid glycosides from Korean red ginseng Panax C.A. Meyer and their aglycons on the phase transitions of model DPPC membranes were studied by microcalorimetry. Glycosides Rb1, Rg1, 20(S) protopanaxadiol only slightly interacted with the DPPC gel phase and caused no formation of new phases. At concentrations close to equimolar values, the glycosides slightly disturbed the packing of lipids and induced the formation of the second phases with more dense lipid packing but smaller sizes of the cooperative domains as compared with pure lipid. Cholesterol (3%) produced no effect on the DPPC interaction with Rb1, Rg1 and panaxatriol but affected the DPPC interaction with panaxadiol. At equimolar panaxadiol/DPPC ratio and in the presence of 3% cholesterol, panaxadiol completely eliminated the main transition.

1,2-Dipalmitoylphosphatidylcholine↗

[Use of glucagon in cardiac glycoside poisoning in patients with congestive circulatory insufficiency].

The use of glucagon in 25 patients with congestive circulatory insufficiency of stage IIB-III (according to the classification suggested by N. D. Strazhesko and V. Kh. Vasilenko) on the background of intoxication due to cardiac glycosides showed the drug to be effective as a cardiotonic and antiarrthythmic agent in 12 patients with stage IIB circulatory insufficiency. The data obtained also bear evidence that glucagon may be used in combination with cardiac glycosides, this treatment in some cases having a more marked positive effect on the hemodynamics in patients with decompensation than that encountered in treatment with glucagon alone. When used together with glucagon, cardiac glycosides did not induce intoxication.

Adult↗

[Therapeutic equivalence and inequivalence of chemically identical substances using cardiac glycosides for an example (author's transpl)].

The problem of therapeutic equivalence or inequivalence cannot be solved by "ignoring facts and proclaiming opinions". The entire problem is multifarious and is not even clearly arranged although heart glycosides have been used for 200 years in the therapy of cardiac insufficiency. It comprises the physico-chemical properties of the drugs, its preparation and its pharmacolinetic behaviour in the organism. Therapeutic equivalence or inequivalence can primarily only be evaluated in connection with the disease and the symptoms of disease, respectively. Thus, manufacturers, pharmacists and physicians likewise are confronted with the problem. The differences in bioavailability of the individual cardiac glycosides show the necessity for: 1. The number of fixed combinations of heart glycosides should be limited in the interest of drug safety. 2. Only such drugs should be approved whose quantitative and qualitative equivalence has been demonstrated with regard to the monoglycoside. 3. When prescribing digoxin derivatives one should not only observe the bioavailability but take also into account the chemical stability and the pharmacolinetic behaviour.

Animals↗

[Radioimmunological estimation of cardiac glycoside concentration in the plasma].

Radioimmunoassay is a simple method for estimating the concentration of cardiac glycosides in the blood. The technique is described. An condition of the accuracy of the estimation is that the drug levels in blood and tissue have reached equilibrium, since only then will the blood concentration accurately reflect the drug level in the tissues. The therapeutic plasma levels are 0.7 to 2.0 ng/ml for digoxin and 10-30 ng/ml for digitoxin. Indications for estimating the plasma glycoside levels are reviewed; they include suspected digitalis poisoning or intolerance, interaction of glycosides with other drugs and suspected negligence on the part of the patient to take the prescribed dose.

Albumins↗

Suspected cardiac glycoside intoxication in sheep and goats in Namibia due to Ornithogalum nanodes (Leighton).

The main clinical and necropsy features of field and experimental cases of suspected cardiac glycoside intoxication following ingestion and dosing of the plant Ornithogalum nanodes, are described. The distribution of intoxication in the area as well as a description of the plant are given. Plant samples tested for cardiac glycosides by fluorescence polarization immuno-assay (FPIA) gave a strong positive reaction. This is a new finding, as other toxic Ornithogalum species in southern Africa are devoid of cardiac glycoside activity and poisoning with them result only in a severe, often fatal diarrhoea, without obvious cardiac involvement. It is also the first record of toxicity of this particular plant.

Animals↗