Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “CYSTAMINE”

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 91 records · Page 5Linked to original sources

Inhibition of acetyl-CoA carboxylase by cystamine may mediate the hypotriglyceridemic activity of pantethine.

Pantethine is a versatile and well-tolerated hypolipidemic agent whose efficacy in this regard appears to be mediated by its catabolic product cystamine, a nucleophile which avidly attacks disulfide groups. An overview of pantethine research suggests that the hypotriglyceridemic activity of pantethine reflects cystamine-mediated inhibition of the hepatic acetyl-CoA carboxylase, which can be expected to activate hepatic fatty acid oxidation. Inhibition of HMG-CoA reductase as well as a more distal enzyme in the cholesterol synthetic pathway may account for pantethine's hypocholesterolemic effects. If pantethine does indeed effectively inhibit hepatic acetyl-CoA carboxylase, it may have adjuvant utility in the hepatothermic therapy of obesity. As a safe and effective compound of natural origin, pantethine merits broader use in the management of hyperlipidemias.

Acetyl-CoA Carboxylase↗

The early effect of sublethal X-irradiation of phagocytic cells in mouse blood and the influence of cystamine as measured by chemiluminescence.

The metabolic burst accompanying phagocytosis of granulocytes (PMN) leads to the generation of activated oxygen species such as O-2, H2O2, 1O2 and OH; which give rise to chemiluminescence (CL) in the presence of luminol. Reliable CL-measurements of stimulated PMN can be carried out in freshly drawn mouse blood, when photon counts are related to the number of PMN. Effects of low dose total body X-irradiation were studied using C57B1/6 mice. It was found that 24 and 48 hours after irradiation (0.24-0.95 Gy) CL of whole blood was slightly decreased. If however CL-counts were related to the number of PMN, an enhanced CL per single granulocyte was recorded. The administration of cystamine leads to an immune stimulating effect of unirradiated animals. In animals, who received 0.95 Gy a distinct radioprotective effect of cystamine can be observed.

Adenosine Diphosphate↗

Increased protective effect of cystamine and mexamine against radiation after activation of the haemopoiesis by dextran sulphate in mice.

The effect gained by activation of haemopoietic cell populations by a single injection of dextran sulphate (DS) on the protective effect of cystamine and mexamine administered in small doses was monitored in mice. On irradiation 24 hours after the injection of DS the number of endogenous spleen colonies increased following the administration of mexamine and cystamine, the number of haemopoietic stem cells surviving in the femur after irradiation increased, and recovery of the cellularity of irradiated bone marrow was accelerated. Both substances administered 24 hours after the injection of DS significantly reduced the lethal effects of gamma rays. The maximum values of the dose reduction factor, for combined radiation protection, reached 1.48 as regards decreased lethal effects and 1.6 as regards equieffective E-MSC exposure.

5-Methoxytryptamine↗

[Effect of unithiol on cystamine toxicity in dogs].

In experiments with dogs it was shown that administration of unithiol before administration of cystamine decreases toxic effect of the last: period of excitation induced by cystamine is shortened, the time of emetic reaction decreases and expression of the emetic reaction to this preparation is diminished, the recorded EKG changes of conditions of heart decrease.

Animals↗

Influence of cystamine on activity and biotransformation of hexobarbital.

Influence of cystamine on hypnotic potency and biotransformation of hexobarbital in rats was studied. Duration of hexobarbital-induced sleep was prolonged maximally by 42% on the first day after premedication, and by 37% on the third day. After six days, differences from the control group were within the limits of experimental error. Biotransformation of hexobarbital was only slightly inhibited in rats premedicated with cystamine, confirmed by determinations of hexobarbital oxidase activity. Excretion of hexobarbital and its metabolites was delayed.

Animals↗

Amelioration of radiation damage to haemopoiesis by Ivastimul, given after irradiation to mice protected by peroral cystamine.

The combined radioprotection by preirradiation peroral cystamine and postirradiation Ivastimul treatment was examined in sublethally and lethally whole-body gamma-irradiated mice. The enhancement of haemopoietic recovery and increased survival of irradiated mice was demonstrated when a single dose of Ivastimul was administered after irradiation. Ameliorative influence of combined radioprotection may be explained by the haemopoietic stem cell protection by cystamine and haemopoietic stimulation mediated by Ivastimul.

Animals↗

Combined radioprotection by preirradiation peroral cystamine and postirradiation glucan administration.

The possibilities of combined radioprotection, using preirradiation peroral cystamine and postirradiation intraperitoneal glucan administration in sublethally and lethally whole-body gamma-irradiated mice were investigated. The results demonstrated at least additive radioprotective effects of both agents, manifested in the enhancement of postirradiation haemopoietic recovery and increased survival of irradiated mice. The effects appear to depend on the sequential cell protection mediated by cystamine and enhanced haemopoietic repopulation induced by glucan.

Animals↗

Enhancement of haemopoietic recovery in sublethally gamma-irradiated mice by the joint use of indomethacin and cystamine.

The effects of indomethacin and cystamine, administered prior to gamma-irradiation of mice, were investigated. Synergistic enhancement of haemopoietic recovery was observed under the conditions of a joint use of both drugs. The reason for this synergistic action is probably a joint operation of two mechanisms, i.e., the lowering of the radiosensitivity of haemopoietic stem cells by cystamine and the increase of the proliferation of surviving haemopoietic cells by indomethacin.

Animals↗

Effect of the pretreatment with pyrazole, cystamine or diphenyl-P-phenylenediamine (DPPD) on the CCl4-promoted pentane evolution in rats.

CCl4 administration to Sprague-Dawley male rats promotes pentane evolution which is an index of lipid peroxidation (LP) occurrence in vivo. Pyrazole (150 mg/kg, ip) or cystamine (600 mg/kg, po) pretreatment do not prevent CCl4-induced increases in pentane evolution, while the prior administration of the powerful antioxidant DPPD (600 mg/kg, ip at 48, 24 and 10 minutes before CCl4) prevents most of it. Since previous studies evidenced that pyrazole and cystamine but not DPPD prevent several early effects of CCl4 and diminish the intensity of the covalent binding of CCl4 reactive metabolites to cellular constituents (CB), results suggest that CB and LP might be related to those deleterious effects of CCl4 on the liver.

Animals↗

[Chromatin breakdown in the white blood cells of rats during irradiation and in combined radiation injury under cystamine protection].

The polydeoxyribonucleotide (PDN) level in leukocytes of peripheral blood of rats treated with cystamine adequately reflects the severity and outcome of radiation sickness. Preventive application of cystamine against the combined effect of ionizing radiation and heat decreased the PDN level in white blood cells but did not influence the survival of animals.

Animals↗

[Comparative study of cystamine conversion in the tissues of white mice and rats].

At different periods following introduction to animals of radioprotector cystamine its unchanged form and oxidation products (hypotaurine and taurine) in tissues were determined. In the tissues of mice and rats the cystamine metabolism is shown to proceed at varying rates, correlating with the level of basal metabolism.

Animals↗

Studies on the effect of cystamine on imipramine metabolism in radiation sickness.

Investigations were carried out for elucidating the effect of cystamine on the metabolism of imipramine in rats irradiated with a dose of 600 R. The investigations were based on determination of desmethylimipramine, the principal metabolite of this drug. It was found that cystamine reduced the serum imipramine level to control values but had no effect decreasing the level of desmethylimipramine. It caused also no fall in the concentration of this metabolite in brain tissue and even it raised this concentration. The authors explained these findings as a result of secondary resorption of desmethylimipramine into the blood stream, and a result of changed activity of beta-glucuronidase, these mechanisms being partly responsible for the overall effect.

Animals↗

Cystamine effect on the pharmacokinetics of imipramine in radiation sickness.

Investigations were carried out on the effect of cystamine premedication (100 mg/kg) before irradiation with 600 R on imipramine (40 mg/kg) kinetics in male Wistar rats. It was found that cystamine prevented changes in blood imipramine level in the irradiated animals but it protected additionally the process of drug elimination from the blood (T 1/2 beta in controls = 1.67 h, in irradiated = 2.38 h, in irradiated premedicated = 4.01 h).

Animals↗

[Effect of cystamine on formation and repair of post-irradiation single-strand DNA breaks].

Content of breaks in single-strand DNA, activity of superoxide dismutase and concentration of malonic dialdehyde were studied in blood lymphocytes of irradiation-impaired rats after treatment with cystamine. Cystamine decreased the effects of irradiation as showed all the patterns studied. The protective action exhibited by the drug in radiation shielding of DNA involved both direct and indirect effects.

Animals↗

Thioltransferase can utilize cysteamine as same as glutathione as a reductant during the restoration of cystamine-treated glucose 6-phosphate dehydrogenase activity.

Glucose 6-phosphate dehydrogenase (G6PD) [EC 1.1.1.49] is inactivated by the incubation with cystamine very efficiently, but not by oxidized glutathione. This inactivation advanced following the incubation-time and concentration of cystamine. The inactivated-G6PD is restored its activity by the treatment of thioltransferase with 1 mM cysteamine or reduced glutathione (GSH) much more effectively than only by thiols. For the first time, we suggested thioltransferase can utilize cysteamine in stead of GSH during its thiol/disulfide exchange reaction activity.

Animals↗

Biochemical and cytotoxic properties of the isomeric forms of N,N'-bis[N-2-chloroethyl)-N-nitrosocarbamoyl] cystamine.

Three isomeric forms of a cystamine-containing chloroethylnitrosourea, N,N'-bis[N-(2-chloroethyl)-N-nitrosocarbamoyl]cystamine (CNCC), have been identified and separated by high pressure liquid chromatography. Isomer S, 3,3'-bis[N-(2-chloroethyl)-N-nitrosocarbamoyl] ethyl disulfide, was significantly less cytotoxic than isomer C, 1,1'-bis [N-(2-chloroethyl)-N-nitrosocarbamoyl] ethyl disulfide, or isomer M, 1,3'-bis[N-(2-chloroethyl)-N-nitrosocarbamoyl] ethyl disulfide, in either a human Namalva lymphoblastoid or a rat Walker 256 carcinoma cell line. Both isomers S and C inhibited DNA synthesis at a 50 microM concentration. A structural analysis of the isomeric forms suggested that bioreduction of the disulfide bond would permit both isomers to produce isocyanate moieties which would carbamoylate intracellular proteins and depress nucleic acid synthesis. The reduced cytotoxic potential of isomer S is consistent with a prolongation in the half-life of production of alkylating carbonium species that lack the capacity to cross-link macromolecules. Overall, the relative position of the NH group within each of the nitrosourea isomers appears critical to the biological properties of the drug.

Animals↗

Cystamine inhibits transglutaminase and caspase-3 cleavage in glutamate-exposed astroglial cells.

Although the precise role of transglutaminase in cell death is unknown, several findings demonstrate that tissue transglutaminase selectively accumulates in cells undergoing apoptosis both in vivo and in vitro. Calcium-dependent transglutaminase reactions are also implicated in several neurodegenerative diseases, including alterations in the release of excitatory amino acids. One prevalent theme in cell damage induced by excitotoxic stimuli in different regions of the CNS is that apoptosis may be executed by intracellular caspase proteases. Furthermore, the presence of functional ion channel-gated receptors in glial cells suggests that also astrocytes can be susceptible to glutamate's toxic effects. In this study, we demonstrated that prolonged exposure to glutamate (100 microM) of cultured astrocytes caused an increase in the expression of tissue transglutaminase (tTG). This effect was prevented by preincubation with GYKI 52466, an antagonist of AMPA/KA receptors. Glutamate exposure also promoted an increase in caspase-3 compared with control cultures. Confocal laser microscopy analysis demonstrated the presence of activated caspase-3 in the cytoplasm as well as in the nucleus. The inhibition of TG-catalyzed reactions by cystamine (1 mM) blocked the activation pathway of caspase-3, with an evident reduction of enzyme cleavage. These results suggest that glutamate increased both TG and caspase-3 in astroglial cells early in the excitotoxin-induced events.

Animals↗