Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Cycloheximide”

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 1,045 records · Page 58Linked to original sources
PubMed1988

[Dynamics of the biosynthesis of components of the protein synthesizing apparatus of the rat liver at the stage of restoration of translation, inhibited by cycloheximide].

The biosynthesis of proteins, ribosomal RNA and other components of the rat liver protein-synthesizing system during the reparation and subsequent activation of translation inhibited by a sublethal dose cycloheximide (CHI, 3 mg/kg) was studied. It was found that the incorporation of labeled precursors into proteins and ribosomal rRNA isolated from free and membrane-bound polysomes is repaired already 3 hours after CHI injection. 6-9 hours thereafter, the level of component labeling reaches control values, whereas the total protein biosynthesis is retarded. After 12-24 hours, marked stimulation of ribosome biosynthesis and the integration of ribosomes into polysomes are observed together with an asymmetric accumulation of excessive amounts of newly synthesized 40S subunits into polysomes 12 hours after CHI infection. The putative mechanisms of the activation of expression of the part of the genome responsible for protein and ribosomal rRNA synthesis as well as for the synthesis of other components of the protein-synthesizing system are discussed.

Animals↗
PubMedDate not supplied

[Effect of cycloheximide on the morphological and biochemical changes in chromatin in non-irradiated and irradiated rat thymocytes].

The level of chromatin degradation was studied and the method of electron-microscopy was used to estimate the changes in the ultrastructure of irradiated and nonirradiated thymocytes of rats treated with cycloheximide. The latter was found to decrease the degree of derangement of nuclear ultrastructure and the level of chromatin degradation in exposed animals and to increase the yield of these damages in thymocytes of nonirradiated animals. The electronmicroscopic determinations showed that the percentage of thymocytes with the impaired nucleus structure is twice as high as that of degraded chromatin. The causes of the quantitative disagreement between the morphological and biochemical indices of the interphase thymocyte death are discussed.

Animals↗
PubMed1987

Effect of cycloheximide on heat-induced cell killing, radiosensitization, and loss of cellular DNA polymerase activities in Chinese hamster ovary cells.

A whole-cell assay technique for DNA polymerase alpha and beta was used to measure the activities of both enzymes in Chinese hamster ovary cells after hyperthermic treatment at 43 degrees C in the presence or absence of 10 micrograms/ml cycloheximide (CHM). In the same experiments, the effect of CHM on heat killing and heat radiosensitization was also investigated. CHM treatment before and during heating protected the cells for all three end points, i.e., heat-induced cell killing, radiosensitization, and loss of cellular DNA polymerase activities.

Animals↗
PubMed1987

Protection of Chinese hamster ovary cells from heat killing by treatment with cycloheximide or puromycin: involvement of HSPs?

Cycloheximide (CHM) or puromycin (PUR) added for 2 h before heating at 43 degrees C followed by either PUR or CHM during heat greatly protected cells from heat killing. This protection increased with inhibition of protein synthesis. Since treatment with a drug both before and during heating was required for heat protection, and since one drug could be exchanged for the other after the 2-h pretreatment without affecting the heat protection, a common mode of action involving inhibition of protein synthesis is suggested for the two drugs. Drug treatment reduced the synthesis of heat-shock proteins (HSPs) as studied by one-dimensional gel electrophoresis by 80-98% relative to 37 degrees C untreated controls. Synthesis of large molecules (greater than 30 kDa) was preferentially inhibited by PUR but not by CHM. Also for CHM, but not for PUR treatment, a 42 kDa band appeared along with a great reduction in the 43 kDa actin band during CHM treatment at both 37 and 43 degrees C. Furthermore, during CHM or PUR treatment, incorporation of [35S]methionine into HSP families 70, 87, or 110 was not increased relative to incorporation into total protein. However, synthesis of the 70 kDa HSP family was selectively suppressed when cells were incubated at 37 degrees C after CHM treatment, but when cells were incubated at 37 degrees C after treatment at 43 degrees C with CHM, synthesis of the 70 kDa HSP family resumed. When cells were labeled for 3 days, there was no preferential accumulation or turnover of HSP families during heating with or without CHM. Therefore, heat protection caused by treatment with CHM or PUR apparently involves a common mode of action not associated with changes in either total levels or synthesis of HSP families during drug treatment before and during heating. The significance of the changes observed in the synthesis of the HSP 70 family after heat is unknown. As thermotolerance developed during 5 h at 42 degrees C without drugs, synthesis of HSP families 70, 87, and 110, as studied with one-dimensional gels, increased 1.4-fold relative to synthesis of total protein, but compared to HSP families in cells labeled for 5 h at 37 degrees C incorporation was reduced by 40%. The increase of unique HSPs, if studied with two-dimensional gels, would probably be much greater.(ABSTRACT TRUNCATED AT 400 WORDS)

Adaptation, Biological↗
PubMed1987

[Characteristics of [3H]cycloheximide distribution, protein and DNA biosynthesis in rat organs after sublethal blocking of translation].

The kinetics of accumulation and release of [3H]cycloheximide (CHI) as well as protein and DNA biosyntheses in some organs of the rats injected with sublethal doses of CHI were studied. It was shown that in the majority of organs under study (especially in the liver, kidneys and adrenals) the inhibition is completed within 12 hours after CHI injection followed by the resumption of protein and DNA syntheses. In the thymus and pancreas the levels of these biosyntheses remain below control values up to the 72nd hour. A positive correlation was observed between the decrease of CHI (or its metabolites) concentration and the beginning of protein and DNA syntheses in different organs. However, there was a reverse correlation between the high values of squares below the kinetic curves of CHI release from the liver, kidneys and adrenals and the intensive resumption of protein and DNA biosyntheses in these organs. It was thus assumed that in these particular organs CHI is subjected to intensive biotransformations. The contribution of the endocrine system to the induction of intensive compensatory protein and DNA syntheses in the liver were estimated from the viewpoint of the nature of reconstructive processes occurring in the appropriate organs.

Animals↗
PubMed1986

Potential subtypes of Chlamydia psittaci based on effects of cortisone with cytochalasin B or cycloheximide.

Strains of Chlamydia psittaci were differentiated as to their biological characteristics using growth in Vero cells. These host cells were chlamydial infected without centrifugation, but treated with either cortisone and cytochalasin B or cortisone and cycloheximide. The criterion was the time of 100% cytopathic effect and specific sloughing, accompanied by the maximum infectivity of C. psittaci. Possible subtypic characteristics were determined for three avian strains.

Cell Division↗
PubMedDate not supplied

[Effect of irradiation on the intensity of chromatin protein synthesis in the rat liver during protection with serotonin in pulsed inhibition of translation by cycloheximide].

The model of impulse translation inhibition by cycloheximide in the rat liver was used for studying the combined and separate effect of serotonin and irradiation on the intensity of synthesis of chromatin proteins (histones and nonhistone proteins). Irradiation induces a considerable inhibition of the protein synthesis intensity, while serotonin has a contrary action, that under conditions of subsequent irradiation provides an increase in the synthesis level of histones and nonhistone proteins. Possible mechanisms of the irradiation and serotonin effect on the synthesis processes of chromatin proteins in the organism are discussed.

Animals↗
PubMedDate not supplied

[Effect of the in vitro conditions of mouse oocyte maturation on their capacity for parthenogenetic activation as affected by cycloheximide and ethanol].

The efficiency of 7% ethanol and cycloheximide (CH) as activators of parthenogenesis was compared on the in vitro matured oocytes of the CBA/C57BL (F1) mice. CH is a more potent activator but the oocytes are activated by ethanol more synchronously. The oocytes matured in the F12, F10 and RPMI 1640 media were activated by ethanol reliably better than those matured in the Minimum Essential Medium Eagle or in the M3 medium. Addition of five amino acids (arginine, alanine, serine, aspartic and glutamic acids), only ornithine or arginine, as well as prolongation of oocyte cultivation in M3 from 19.5 to 26.5 h reliably increased the percentage of activated oocytes.

Animals↗
PubMed1986

Protection of Chinese hamster ovary cells from hyperthermic killing by cycloheximide or puromycin.

Cycloheximide (CHM) and puromycin (PUR) were used at various concentrations up to maxima of 10 micrograms/ml and 100 micrograms/ml, respectively, which inhibited protein synthesis by 95% without any cytotoxicity. The drugs were added to the cells for a maximum period of 7 h, with various combinations for treatment before, during, and after heating. Maximum protection, i.e., a 10,000-fold increase in survival from 5 X 10(-6) to 5 X 10(-2) after 4 h at 43 degrees C, required both 1-2 h of treatment before heating and 1-2 h of treatment during heating. For treatments at 45.5 degrees C, the protection was less, i.e., a 100-fold increase in survival from 10(-5) to 10(-3). Little or no protection was observed if after treatment, the drug was removed before heating, or if the drug was added at the start of heating and left on for 5 min to 3 h after heating. For both drugs, the amount of protection increased as inhibition of protein synthesis increased. However, the amount of protection from the drugs was the same only at about 95% inhibition; at 60-85% inhibition, CHM afforded more protection than PUR. Therefore, the modes of action of the drugs might be common at high drug concentrations, but different when intermediate concentrations are used.

Animals↗
PubMed1985

Changes in rat liver immunoreactive cathepsin D after cycloheximide.

A rocket immunoelectrophoretic procedure has been developed for the assay of cathepsin D (EC 3.4.23.5) immunoreactive protein, in a 10-100 ng range, directly on crude soluble liver homogenate extracts. By this method, the drop in activity of rat liver cathepsin D effected by repeated doses of cycloheximide, a protein synthesis inhibitor, reflects a parallel change in total enzyme protein content, the specific activity being stable in the course of the treatment. These observations are compatible with the hypothesis that ongoing enzyme degradation, coupled with impaired synthesis, accounts for such a decline of cathepsin D.

Animals↗
PubMedDate not supplied

[Crithidia oncopelti (Kinetoplastmonada) strains resistant to cycloheximide and chloramphenicol].

By gradual (during several months) increase of the concentrations of cycloheximide (C) and chloramphenicol (Ch) in cultural medium there were obtained strains of C. oncopelti resistant to the effect of 20, 50, 100 mkg/ml and 2.5 mg/ml Ch. During 38, 28, 19 and 12 subculturings (that corresponds to 160, 120, 80 and 50 cell generations, respectively) on media without inhibitors parasites preserve their resistance to corresponding concentrations of C and Ch without essential changes. Cross resistance between obtained strains of Crithidia was missing. Therefore, the characters of resistance to C and Ch are rather specific, genetically specified and can be used as genetical markers.

Animals↗
PubMed1985

In vitro synthesis of IgE in atopic and nonatopic individuals: the effects of pokeweed mitogen, Staphylococcus aureus-derived mitogens, and cycloheximide.

We studied the production of immunoglobulin (Ig)E in cultures containing mononuclear cells obtained from atopic and nonatopic subjects. The two groups did not differ in their baseline production of IgE. Pokeweed mitogen (PWM) and three different products of Staphylococcus aureus: purified protein A, heat-killed formalinized bacteria, and double-formalinized bacteria--induced a significant increase in the in vitro production of IgE. Mononuclear cells from both atopic and nonatopic individuals were stimulated to the same degree by all four mitogens. The increased production of IgE by PWM was totally abolished by cycloheximide; hence it was due to de novo protein synthesis.

Adolescent↗
PubMed1985

[Structural characteristics of DNA from the rat liver during inhibition of protein synthesis with cycloheximide].

At cot around 20, the rat liver DNA reassociation curves were obtained 12-48 hours after injection of the animals with sublethal doses of cycloheximide. In total preparations of DNA-24 and DNA-36 at cot 0.02-0.06, the number of fast reassociating sequences was increased, on the average, by 4%. The differences in reassociation rates for individual kinetic fractions are 2.5-3-fold. The total incorporation of the label into DNA-24 preparations is sharply decreased; however, a marked distinction in the incorporation between the fractions in parameter cot was observed.

Animals↗
PubMed1985

Reversal of antibody-dependent cellular cytotoxicity suppression by cycloheximide.

Antibody-dependent cell-mediated cytotoxicity (ADCC) carried out by fresh and precultured peripheral blood mononuclear cells (PBMC) was compared. The results indicate that the cytotoxic capability was decreased in precultured PBMC, probably due to the effect of suppressor cells. The depletion of adherent cells before preincubation eliminated inhibitory effects, suggesting that the suppressor activity resided in this cell fraction. In addition, supernatants from adherent cell cultures were also able to suppress ADCC of non-adherent PBMC. Normal ADCC values were restored by supplementing the reaction medium with cycloheximide (Cy) 1 X 10(-3) M. The enhancing effect of Cy was exerted upon whole and adherent PBMC, while the opposite effect was observed when ADCC was carried out by non-adherent cells. The fact that Cy increased ADCC activity by precultured PBMC might rule out the possibility that suppression could be ascribed to trivial factors such as cell death, overcrowding or steric hindrance. The results presented in this report support the premise that ADCC is under active immunoregulation.

Antibody-Dependent Cell Cytotoxicity↗
PubMedDate not supplied

[The effect of cycloheximide and actinomycine D on the spontaneous and operative behaviours of the pigeon (author's transl)].

Three groups of pigeons were studied: controls, pigeons treated with cycloheximide and pigeons treated with actinomycine D. It was noticed that in the first group spontaneous activity increased during different trials and that learning was rapid. In the second group, spontaneous activity remained constant during sucessive experiments while learning improved slowly. In the third group, spontaneous activity gradually disappeared and learning was non-existant. There is a parallelism between spontaneous and operative behavior in the control groups as well as in the treated animals.

Animals↗
PubMed1979

Changes induced by fasting and cycloheximide in the vacuolar apparatus of rat hepatocytes. A morphometric investigation.

An increase in the number of autophagic vacuoles and in the size of the dense and residual bodies was observed in the hepatocytes of rats fasted for 24 hours; moreover, the number of dense bodies was reduced. These data suggest that the previously reported acceleration in cell protein degradation caused by fasting can be accounted for by enhanced autography. The treatment with cycloheximide, which was previously found to prevent this proteolytic response, also prevents the appearance of signs of enhanced autophagic activity.

Animals↗
PubMed1977

[Effect of chloramphenicol and cycloheximide on synthesis of delta-aminolevulinate dehydratase in green and greening barley shoots].

The synthesis of sigma-aminolevulinate dehydratase (EC 4.2.1.24) in green or greening barley shoots was shown to increase, when the plants were grown on chloramphenicol solutions of varying concentrations for 48 hrs upon illumination. This was evidenced from the increase in the enzyme activity of the chloroplast preparations isolated from the shoots as compared to the controls grown in aqueous media. Similar treatment by cycloheximide resulted in inhibition of the enzyme synthesis as observed in the experiments with green and greening shoots. The activity of porphobilinogenase (the porphobilinogene deaminase and uroporphirinogene III cosynthetase complex) showed similar dependence on the effect of the antibiotics. The results obtained are discussed in terms of localization of the chloroplast enzyme syntheses inside the cell.

Ammonia-Lyases↗
PubMedDate not supplied

[Action of cycloheximide on the ultrastructure and metabolic processes in a swine embryo kidney cell culture. I].

Cycloheximide treatment (for 24 hrs, concentrations 1 and 10 microgram/ml) strongly inhibits the intensity of protein and DNA synthesis and the mitotic activity in cells of a pig embryo kidney culture, to a lesser extent inhibits the RNA synthesis in nuclei and nucleoli, reduces the activity of succinate-, lactate- and alpha-glycerophosphate dehydrogenases. There is a condensation of chromatin, a distortion of the granular endoplasmic reticulum integrity, a partial release of its membranes from the ribosomes, changes in the structure of the Golgi complex, morphology and ultrastructure of mitochondria. All these changes are secondary ones and are connected with the suppression of protein synthesis in cells.

Animals↗