Search results for "sulfide"
showing 10 items of 388 documents
Synthesis of Both Ionic Species of Ammonium Dithiocarbamate Derived Cholic Acid Moieties
2011
The reaction of 3-aminopropylamide of cholic acid with CS2 produced a bile acid derivative of dithiocarbamic acid which further formed an ammonium salt with another molecule of 3-aminopropylamide of cholic acid. The cationic 3-ammonium propylamide of cholic acid did not react further with CS2 and the formed salt was stable in the reaction mixture, even when excess CS2 was used. When the reaction was carried out in the presence of aqueous sodium hydroxide, only the bile acid derivative of sodium dithiocarbamate was formed. The dithiocarbamate derivatives were characterized by 1H- and 13C-NMR spectroscopy and ESI-TOF mass spectrometry.
Potassium channels contribute to the increased sensitivity of the rabbit carotid artery to hydrogen sulfide in diabetes
2019
Abstract Hydrogen sulfide (H2S) is a potential endothelium-derived hyperpolarizing factor (EDHF) and adventitium- or adipocyte-derived relaxing factor (ADRF) which vasorelaxant action is mediated by potassium channels. H2S could also play an important role in the pathophysiology of diabetic cardiovascular complications. The present study has investigated the influence of alloxan-induced diabetes on the role of potassium channels mediating the relaxant response of the rabbit carotid artery to NaHS, a donor of H2S. NaHS (10−8-3 × 10−5 M) relaxed phenylephrine-precontracted carotid arteries, with higher potency in diabetic than in control rabbits. The selective blockers of potassium channels c…
Activity and immunohistochemistry of DT-diaphorase in hamster and human kidney tumours.
1994
We have studied the biochemical and immunohistochemical changes of DT-diaphorase in diethylstilbestrol (DES)-induced hamster kidney tumours and human biopsies from normal kidneys and renal clear cell carcinoma. The activities of primary and secondary antioxidants in these hamster and human tissues are also reported. DT-diaphorase is decreased in the different subcellular fractions of hamster and human tissues. In hamster kidney the activities of the one-electron quinone reductases show a nearly two-fold increase. Immunohistochemical findings confirm the decrease in DT-diaphorase in hamster and human tissues. This image is of special interest in the case of nephroblastoma (Wilms' tumour), si…
Oxidative stress in bisphosphonate-related osteonecrosis of the jaws
2013
Objectives To analyze whether oxidative stress (OS) changes are present in patients with bisphosphonate-related osteonecrosis of the jaw (BRONJ) versus controls. Materials and Methods Oxidative stress was analyzed in serum and unstimulated saliva of three groups: Group 1 consisted of 24 patients who had been treated with intravenous bisphosphonates (ivBPs) and developed BRONJ, group 2 consisted of 20 patients who had received ivBPs and did not develop BRONJ, and group 3 comprised 17 control subjects. Reduced glutathione (GSH), malondialdehyde (MDA), oxidized glutathione (GSSG), and 8–oxo-7,8-dihydro-2-deoxyguanosine (8-oxo-dG) levels, as well as the GSSG/GSH ratio, were measured. Results Me…
Gender- and age-related distinctions for the in vivo prooxidant state in Fanconi anaemia patients.
2004
Abstract Some selected oxidative stress parameters were measured in 56 Fanconi anaemia (FA) patients (42 untransplanted and 14 transplanted), 54 FA heterozygotes (parents) and 173 controls. Untransplanted FA patients showed a highly significant increase in leukocyte 8-hydroxy-2’-deoxyguanosine (8-OHdG) (p = 0.00003) and a borderline increase (p = 0.076) in urinary levels of 8-OHdG vs. child controls. These increases were more pronounced in female FA patients (p = 0.00005 for leukocyte 8-OHdG, and p = 0.021 for urinary 8-OHdG). Female FA patients also displayed a highly significant excess of spontaneous chromosomal breaks vs. male patients (p = 0.00026), in the same female:male ratio (≅ 1.4)…
Regulation of glutathione metabolism in Ehrlich ascites tumour cells.
1992
Glutathione metabolism was studied in cancer cells during the growth of an Ehrlich ascites tumour. GSH, but not GSSG, content decreases when cell proliferation and the rate of protein synthesis in the tumour decrease. This change correlates with a decrease in the rate of GSH synthesis and an increase in glutathione peroxidase and glutathione S-transferase activities. Glutathione efflux from tumour cells seems to co-ordinate with the rate of GSH synthesis. Cysteine, and not methionine, promotes GSH synthesis in tumour cells. However, changes in the rate of GSH synthesis are not due to limitations in the supply of blood cysteine or to changes in the intracellular amino acid pool of the cancer…
Modification of hepatic drug-metabolizing enzymes in rat fed naturally occurring allyl sulphides
1994
1. The effects of feeding allyl sulphides to rat (2000 ppm of the diet for 15 days) were investigated on various microsomal hepatic drug-metabolizing enzymes by their immunochemical detection and catalytic activity. 2. Allyl sulphides provoked a temporary dietary restriction, which enhanced the microsomal level of P450 and the activities of NADH-cytochrome c reductase and p-hydroxybiphenyl UDP-glucuronyltransferase (UDPGT 2), and lowered the activities of p-nitrophenol hydroxylase (PNPH), N-nitrosodimethylamine demethylase (NDMAD), laurate omega-hydroxylase (LAH) and glutathione S-transferase (GST). Therefore, pair-fed animals were used as a more relevant control for the dietary effects of …
Hepatic metabolism of diallyl disulfide in rat and man
2003
International audience; 1. The metabolism of diallyl disulphide was investigated in vitro with rat and human liver cell subfractions and ex vivo with an isolated perfused rat liver. 2. Diallyl disulphide was oxidized to diallylthiosulphinate by rat liver microsomes with an apparent K-m = 0.86 +/- 0.1 mM and an apparent V-max = 0.47 +/- 0.12 nmol min(-1) mg(-1) protein (mean +/- SE). Both cytochrome P450 (CYP) and flavin-containing monooxygenases were involved, with CYP2B1/2 and CYP2E1 being the most active CYP enzymes. 3. In rat and man, microsomal oxidation of allylmethyl sulphide to allylmethyl sulphoxide and allylmethyl sulphone also occurred, although at a low rate. Diallyl disulphide w…
Dose-dependent metabolic disposition of hydroxytyrosol and formation of mercapturates in rats
2013
Hydroxytyrosol (HT), one of the major polyphenols present in olive oil, is known to possess a high antioxidant capacity. The aim of the present study was to investigate dose dependent (0, 1, 10 and 100 mg/kg) alterations in the metabolism of HT in rats since it has been reported that metabolites may contribute to biological effects. Special attention was paid to the activation of the semiquinone quinone oxidative cycle and the formation of adducts with potential deleterious effects. Thus, we developed a novel analytical methodology to monitor the in vivo formation of the HT mercapturate, N-acetyl-5-S-cysteinyl-hydroxytyrosol in urine samples. Biomarkers of hepatic and renal toxicity were ev…
Production of T suppressor factor specific for the hapten picryl chloride requires both T suppressor cells and an antigen-specific, genetically restr…
1987
Summary We investigated the requirement for activation of T suppressor cells specific for the hapten picryl chloride and the release of hapten-specific T suppressor factor. Using an in vivo experimental system, we report that activation of T suppressor cells and the consequent release of T suppressor factor required two signals: one was provided by primed T suppressor cells, i.e. spleen cells from mice injected with the tolerogen picrylsulphonic acid, and the other was provided by the specific antigen in the context of H-2 gene products. Mechanisms by which the interaction between these two signals led to activation of T suppressor cells and the production of T suppressor factor, as well as…