Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.3.5.1 (succinate dehydrogenase)
 8,177 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of tetragalloylglucose (1,2,3,6-tetra-O-galloyl-beta-D-glucose) on purified complex II (succinate-ubiquinone oxidoreductase) of the mitochondrial electron transport system of Ascaris muscle were studied. Both succinate-ubiquinone-1 (Q1) oxidoreductase, and succinate dehydrogenase measured with 3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide (MTT) in the presence of phenazine methosulfate (PMS) were inhibited by tetragalloylglucose. The inhibitions of both reductase activities of complex II were of competitive type, and the inhibitor constant (Ki) for Ascaris complex II (148 nM) was lower than that for rat liver complex II (1.5 microM). Thus, Ascaris complex II is much more sensitive to this inhibitor than the mammalian counterpart.
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PMID:Inhibitory effects of tetragalloylglucose on the complex II of mitochondrial respiratory chain of Ascaris muscle. 260 4

Twenty lines of human gastro intestinal and breast cancer xenografts, in which chemosensitivity spectra by the in vivo nude mouse assay had been clarified. were subjected to the in vitro SDI (succinate dehydrogenase inhibition) assay using MTT dye to assess the accuracy of this drug sensitivity test against 4 drugs i.e., mitomycin C (MMC), adriamycin (ADM) 5 fluorouracil (5-FU), and cisplatin (CDDP). After 3 days incubation, the suspension of every tumor cells including small fragments showed a marked decrease of SD activity even when no anticancer drug was added to the assay medium. Among these 4 drugs evaluated MMC exhibited a statistically significant correlation between chemosensitivity values of the in vitro SDI assay and those of the nude mouse assay. However, the other 3 drugs demonstrated no correlation between the values of these two methods. Since the primary cultured fibroblasts revealed, in general, lower sensitivity to these drugs, contamination of fibroblast may decrease the SDI values when materials from solid tumors with rich stroma such as a type of stomach cancer were subjected. It is considered that the prediction of chemosensitivity to every drug will be impossible by a in vitro SDI assay.
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PMID:[Evaluation of predictability of in vitro SDI assay in comparison with in vivo nude mouse assay]. 280 37

We compared the colorimetric reactions between the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl 2H-tetrazolium bromide (MTT) assay and the succinate dehydrogenase inhibition (SDI) test, in order to evaluate the usefulness of the SDI test for in vitro chemosensitivity testing. The addition of sodium succinate enhanced the colorimetric absorbance at 565 nm in the MTT assay in a dose- and a time-dependent manner, in mouse sarcoma-180 (S-180) cells. At 10 microM of sodium succinate, a dose used in the SDI test, the absorbance of the MTT assay increased by about 2.5-fold in the S-180 cells and in 10 human tumor tissues. The absorbance in the SDI test correlated well with the viable cell number of S-180 cells (r = 0.9993). These results show that the SDI test, using MTT as a tetrazolium salt, has a higher sensitivity for predicting cell viability, compared to the MTT assay.
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PMID:Sodium succinate enhances the colorimetric reaction of the in vitro chemosensitivity test: MTT assay. 318 53

The Escherichia coli membrane-bound D-lactate dehydrogenase and succinate dehydrogenase were assayed on the basis of the phenazine methosulfate- (PMS-) mediated reduction of the tetrazolium salt, MTT. An initial slower phase (lag) in the time-course of the reaction was observed and analyzed. The results were as follows. (1) The time lag in the assay of the D-lactate dehydrogenase was eliminated by preincubating the membranes with PMS plus D-lactate, with PMS plus succinate, or with PMS plus NADH (conditions which implicated PMS reduction). (2) When the D-lactate dehydrogenase was assayed by another method based on the measurement of the pyruvate formed, neither was a time lag observed nor was the enzyme activity affected by membrane preincubation with PMS plus D-lactate. (3) Although the superoxide radical was involved in MTT reduction, this radical seemed not to participate in the generation of the time lag. (4) Membranes whose D-lactate dehydrogenase activity had previously been destroyed by heating at 80 degrees C for 1 min, were able to prolong the time lag in MTT reduction when added to the assay medium for the D-lactate dehydrogenase from untreated membranes, whereas membranes previously heated at 100 degrees C instead of 80 degrees C did not have this effect. It was concluded that the E. coli membranes interfered in the dehydrogenase assay based on the PMS-mediated reduction of MTT. The time lag was interpreted as a period during which the interfering substance reacted with reduced PMS inhibiting the reduction of MTT.
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PMID:Study of a time lag in the assay of Escherichia coli membrane-bound dehydrogenases based on tetrazolium salt reduction. 388 Nov 33

In vitro chemosensitivity was evaluated by SDI test in various human tumors including 1 lymph node metastasis of esophageal cancer, 10 gastric cancers, 4 colo-rectal cancers, 1 hepatoma, 2 lung cancers, 2 breast cancers and 1 gallbladder cancer. Tumor fragments cut with scissors were exposed to twelve kinds of antitumor drugs at five to ten times peak plasma concentration. After 3 days at 37 degrees C, each tumor fragment suspension was washed with phosphate-buffered saline and assayed for succinate dehydrogenase (SD) activity using 3-(4,5- dimethyl-2-thiazolyl)-2, 5-diphenyl-2H tetrazolium bromide (MTT) as a hydrogen acceptor. When the SD activity of the drug-treated cells was reduced to below 50% that of control cells, the chemosensitivity to the antitumor drug was considered positive. The chemosensitivity of each tumor varied individually. Mitomycin C or 5-fluorouracil are regularly used to treat gastric cancer patients, but, some specimens of gastric cancer in this study showed a resistance to these drugs and an unexpected sensitivity to other drugs. Our results show that the SDI test is a convenient method for clinical use and gives significant information about drug sensitivity.
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PMID:[In vitro chemosensitivity of various human tumors evaluated by the SDI (succinate dehydrogenase inhibition) test]. 405 18

The activity of succinate dehydrogenase (SDH) of liver parenchyma was histochemically determined by use of tetrazolium salts MTT and elutions technique on pubescent male rats prior to irradiation and during 30 days following single total-body X-radiation with 800 R (approx. LD 90/30). These data were compared with those after a single post-radial application of L-cysteine and tetrahydrofolic acid (FH 4). After irradiation and cysteine FH 4 therapy the SDH activity of the liver, in general, showed values which were significantly different from control and experimental groups. The higher enzyme activities were almost exclusively found in the treated animals. The minimum of the regression phase was reached on day 6 after irradiation. Approximately normal values were observed not before two weeks following irradiation, but only as consequence of cysteine/FH 4 therapy. In untreated animals, the SDH activity until on day 30 after irradiation was lower than 50% when compared to normal rats. The determined changes of SDH-activity from day 3 to day 15 after irradiation parallel those post-radial changes of body weight, blood picture and mortality which were found in comparative experiments under identical radiation conditions.
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PMID:[Interpretation of histochemical changes of succinate dehydrogenase activity in liver parenchyma during the monitoring of the clinical course of the acute radiation syndrome: study of sublethally whole-body irradiated rats]. 642 55

The activities of lactate dehydrogenase, succinate dehydrogenase and glutamate dehydrogenase, originating from rat hippocampus were determined 3, 10, 20 and 40 days post partum. Hemispheric asymmetry was tested using tetrazolium salt MTT-bromide and the elution technique. It could be revealed that significant differences between enzymatic activities occur between both hemispheres of the hippocampus. The greatest difference observed was 14%. Our dates show that a predominantly left-side dominance takes place in the hippocampus.
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PMID:[The activity of several dehydrogenases in both hemispheres of the hippocampus from rats during some phases of postnatal development (author's transl)]. 728 91

Gliotoxin, an epipolythiodioxopiperizine mycotoxin, has been shown to be produced by, among other fungi, Aspergillus fumigatus Fresenius. This organism is the major causative agent of the respiratory disease aspergillosis in avian species, especially turkeys. Because gliotoxin has been shown to be immunosuppressive and has the potential for being involved in the pathogenesis of aspergillosis, the in vitro activity of this compound with avian lymphocytes was investigated. Immunosuppression was investigated using peripheral blood lymphocytes from turkeys in a lymphoblastogenesis assay and a cytotoxicity assay using conversion of the tetrazolium salt MTT to MTT formazan by the mitochondrial succinate dehydrogenase enzyme elaborated only by living cells. Gliotoxin appeared to have a threshold level in both tests because little or no response or stimulation was evident when cells were exposed to concentrations of the toxin below 100 ng/ml, but at 100 ng/ml, all cells appeared to be dead. Using T-2 mycotoxin as a known cytotoxic agent, the response in the MTT bioassay using turkey peripheral lymphocytes was linear with increasing concentrations of toxin. Gliotoxin may potentially cause immunosuppression in turkey poults through action on the lymphocytes or if this toxin were present in low concentrations stimulation could possibly occur.
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PMID:Gliotoxin inhibits transformation and its cytotoxic to turkey peripheral blood lymphocytes. 752 May 34

beta-Amyloid cores contain considerable amounts of D-Ser and D-Asp residues in Alzheimer's disease. We investigated the cytotoxic effects of various synthetic beta-amyloids, including D-Ser-substituted derivatives, on primary cultured neurons and nonneuronal HeLa cells. beta 25-35, its D-Ser26-substituted derivative, and beta 1-40 in 10-100 nM specifically suppressed mitochondrial succinate dehydrogenase activity [MTT [3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide] reduction] in HeLa cells, which are dependent on ATP production mainly from glycolysis, but did not exert detectable cytotoxicity, assessed by dye exclusion test, NADH levels, and uptake of [3H]Leu and [3H]Tdr. The beta-amyloids, on the other hand, did exert neurodegenerative effects on rat hippocampal cultured neurons in which ATP is mostly synthesized by the mitochondrion. The activities of beta 25-35 and [D-Ser26] beta 25-35 are dependent on their having beta-structures and not random forms. Although beta 25-35 was degraded rapidly by proteinase(s) in brain extract or leucine aminopeptidase, [D-Ser26] beta 25-35 is fairly resistant. These results indicate that one of the primary targets of beta-amyloids is suppression of mitochondrial succinate dehydrogenase, and the vulnerability of the brain of beta-amyloids can be explained by its large dependence on mitochondrial energy production. Moreover, racemization of serine residues of beta-amyloids may be involved in neurodegeneration and formation of senile plaques through escaping from the degradation process by brain proteinases.
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PMID:Suppression of mitochondrial succinate dehydrogenase, a primary target of beta-amyloid, and its derivative racemized at Ser residue. 897 58

For antitumor drug sensitivity testing we have been performing the succinic dehydrogenase inhibition test using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). A new tetrazolium salt 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenyl-amino) carbonyl]-2H-tetrazolium hydroxide (XTT) has been synthesized recently, and we have been conducting basic studies using it. We were able to obtain a high degree of sensitivity by adding phenazine methosulfate as a promoter in this assay. In these assays, there was a positive correlation between absorbance and cell count and XTT assay was more sensitive than MTT assay. In XTT assay, the production of formazan increases with reaction time over a protracted period of time, we assessed the possibility of performing assays with fewer cells than MTT was used. The results using cancer cell lines showed that when reacted for a longer time (6 h), it was possible to perform adequate assays using this method with 5,000 cells per well, and it will be useful when the amount of biopsy specimen is limited. We also evaluated the inhibition index of each of the drugs, comparing it with the MTT assay.
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PMID:High-sensitivity antitumor drug sensitivity testing. 797 Apr 99


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