RESUMEN
Based on the reactive oxygen species (ROS) regulatory properties of diphenyleneiodonium (DPI), we investigated the effects of DPI on host-infected T. gondii proliferation and determined specific concentration that inhibit the intracellular parasite growth but without severe toxic effect on human retinal pigment epithelial (ARPE-19) cells. As a result, it is observed that host superoxide, mitochondria superoxide and H2O2 levels can be increased by DPI, significantly, followed by suppression of T. gondii infection and proliferation. The involvement of ROS in anti-parasitic effect of DPI was confirmed by finding that DPI effect on T. gondii can be reversed by ROS scavengers, N-acetyl-L-cysteine and ascorbic acid. These results suggest that, in ARPE-19 cell, DPI can enhance host ROS generation to prevent T. gondii growth. Our study showed DPI is capable of suppressing T. gondii growth in host cells while minimizing the un-favorite side-effect to host cell. These results imply that DPI as a promising candidate material for novel drug development that can ameliorate toxoplasmosis based on ROS regulation.
Asunto(s)
Antiprotozoarios/farmacología , Células Epiteliales/efectos de los fármacos , Células Epiteliales/parasitología , Factores Inmunológicos/farmacología , Compuestos Onio/farmacología , Especies Reactivas de Oxígeno/metabolismo , Toxoplasma/crecimiento & desarrollo , Antiprotozoarios/toxicidad , Línea Celular , Células Epiteliales/fisiología , Humanos , Factores Inmunológicos/toxicidad , Compuestos Onio/toxicidad , Epitelio Pigmentado de la Retina/efectos de los fármacos , Epitelio Pigmentado de la Retina/parasitología , Toxoplasma/efectos de los fármacosRESUMEN
The synthesis of a series of bifunctional Gd(III) complexes 1-3 covalently bound to arylphosphonium cations possessing a varying degree of delocalisation at the phosphonium centre is presented. The influence of the degree of delocalisation was investigated with regards to in vitro cytotoxicity, cellular uptake of Gd, tumor-cell selectivity and intracellular localisation of Gd within human glioblastoma (T98G) and human glial (SVG p12) cells. Cellular uptake and selectivity studies for the Gd(III) complexes indicate that a reduced delocalisation at the phosphonium centre can lead to an enhanced Gd uptake into SVG p12 cells which results in a decrease in the overall tumor cell selectivity. Synchrotron X-ray fluorescence (microbeam XRF) imaging has demonstrated for the first time that uniform uptake of Gd(III) complex 2 within a population of T98G cells increased as a function of increasing Gd incubation times. The Gd maps show dispersed spots of high intensity which are consistent with mitochondrial uptake.
Asunto(s)
Complejos de Coordinación/farmacología , Gadolinio/química , Compuestos Onio/farmacología , Compuestos Organofosforados/farmacología , Línea Celular Tumoral/metabolismo , Complejos de Coordinación/química , Complejos de Coordinación/metabolismo , Complejos de Coordinación/toxicidad , Humanos , Mitocondrias/metabolismo , Estructura Molecular , Compuestos Onio/química , Compuestos Onio/metabolismo , Compuestos Onio/toxicidad , Compuestos Organofosforados/química , Compuestos Organofosforados/metabolismo , Compuestos Organofosforados/toxicidadRESUMEN
A series of permeating cations based on alkyl derivatives of triphenylphosphonium (C(n)-TPP(+)) containing linear hydrocarbon chains (butyl, octyl, decyl, and dodecyl) was investigated in systems of isolated mitochondria, bacteria, and liposomes. In contrast to some derivatives (esters) of rhodamine-19, wherein butyl rhodamine possessed the maximum activity, in the case of C(n)-TPP a stimulatory effect on mitochondrial respiration steadily increased with growing length of the alkyl radical. Tetraphenylphosphonium and butyl-TPP(+) at a dose of several hundred micromoles exhibited an uncoupling effect, which might be related to interaction between C(n)-TPP(+) and endogenous fatty acids and induction of their own cyclic transfer, resulting in transport of protons across the mitochondrial membrane. Such a mechanism was investigated by measuring efflux of carboxyfluorescein from liposomes influenced by C(n)-TPP(+). Experiments with bacteria demonstrated that dodecyl-TPP(+), decyl-TPP(+), and octyl-TPP(+) similarly to quinone-containing analog (SkQ1) inhibited growth of the Gram-positive bacterium Bacillus subtilis, wherein the inhibitory effect was upregulated with growing lipophilicity. These cations did not display toxic effect on growth of the Gram-negative bacterium Escherichia coli. It is assumed that the difference in toxic action on various bacterial species might be related to different permeability of bacterial coats for the examined triphenylphosphonium cations.
Asunto(s)
Bacillus subtilis/efectos de los fármacos , Mitocondrias Hepáticas/efectos de los fármacos , Compuestos Onio/toxicidad , Compuestos Organofosforados/química , Animales , Bacillus subtilis/metabolismo , Ácidos Grasos/metabolismo , Liposomas , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Mitocondrias Hepáticas/metabolismo , Membranas Mitocondriales/efectos de los fármacos , Membranas Mitocondriales/metabolismo , Compuestos Onio/química , Compuestos Organofosforados/toxicidad , Plastoquinona/análogos & derivados , Plastoquinona/química , Plastoquinona/toxicidad , Protones , Ratas , Relación Estructura-ActividadRESUMEN
Transient receptor potential ankyrin 1 (TRPA1) is a Ca(2+)-permeable nonselective cation channel expressed in neuronal and nonneuronal cells and plays an important role in acute and inflammatory pain. Here, we show that an NADPH oxidase (NOX) inhibitor, diphenyleneiodonium (DPI), functions as a TRPA1 activator in human embryonic kidney cells expressing human TRPA1 (HEK-TRPA1) and in human fibroblast-like synoviocytes. Application of DPI at 0.03-10 µM induced a Ca(2+) response in HEK-TRPA1 cells in a concentration-dependent manner. The Ca(2+) response was effectively blocked by a selective TRPA1 antagonist, HC-030031 (HC). In contrast, DPI had no effect on HEK cells expressing TRPV1-V4 or TRPM8. Four other NOX inhibitors, apocynin (APO), VAS2870 (VAS), plumbagin, and 2-acetylphenothiazine, also induced a Ca(2+) response in HEK-TRPA1 cells, which was inhibited by pretreatment with HC. In the presence of 5 mM glutathione, the Ca(2+) response to DPI was effectively reduced. Moreover, mutation of cysteine 621 in TRPA1 substantially inhibited the DPI-induced Ca(2+) response, while it did not inhibit the APO- and VAS-induced responses. The channel activity was induced by DPI in excised membrane patches with both outside-out and inside-out configurations. Internal application of neomycin significantly inhibited the DPI-induced inward currents. In inflammatory synoviocytes with TRPA1, DPI evoked a Ca(2+) response that was sensitive to HC. In mice, intraplantar injection of DPI caused a pain-related response which was inhibited by preadministration with HC. Taken together, our findings demonstrate that DPI and other NOX inhibitors activate human TRPA1 without mediating NOX.
Asunto(s)
Inhibidores Enzimáticos/farmacología , NADPH Oxidasas/antagonistas & inhibidores , Proteínas del Tejido Nervioso/agonistas , Compuestos Onio/farmacología , Canales de Potencial de Receptor Transitorio/agonistas , Animales , Conducta Animal/efectos de los fármacos , Calcio/metabolismo , Canales de Calcio/genética , Canales de Calcio/metabolismo , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/toxicidad , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo , Glutatión/metabolismo , Células HEK293 , Humanos , Inflamación/metabolismo , Potenciales de la Membrana , Ratones , NADPH Oxidasas/metabolismo , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/metabolismo , Compuestos Onio/toxicidad , Dolor/inducido químicamente , Dolor/fisiopatología , Dolor/psicología , Umbral del Dolor/efectos de los fármacos , Membrana Sinovial/efectos de los fármacos , Membrana Sinovial/metabolismo , Canal Catiónico TRPA1 , Factores de Tiempo , Transfección , Canales de Potencial de Receptor Transitorio/genética , Canales de Potencial de Receptor Transitorio/metabolismoRESUMEN
BACKGROUND/AIM: Deferoxamine (DFO), an iron chelator, has been reported to induce hypoxia-inducible factor-1α (HIF-1α) expression. HIF-1α plays a critical role in promoting tumor metastasis. However, the molecular mechanisms underlying induction of HIF-1α in breast cancer cells remain unknown. Our aim was to ascertain whether DFO enhanced cancer metastasis in MDA-MB-231 cells. METHODS: Cellular reactive oxygen species (ROS) was measured by flow cytometry. Cell migration was determined by wound healing and transwell assays. Protein and mRNA expression were detected by western blotting and RT-PCR, respectively. RESULTS: DFO treatment enhanced cell migration and invasion, while HIF-1α expression was significantly up-regulated at the post-transcriptional level. However, treatment with a NADPH oxidase inhibitor, diphenyleneiodonium (DPI), strongly inhibited ROS generation and HIF-1α expression, as well as cell migration and invasion. Notably, DFO treatment increased extracellular signal-regulated kinase (ERK)1/2 phosphorylation. Inhibition of ROS production with DPI attenuated DFO-induced ERK1/2 activation. Moreover, a MEK1 inhibitor, PD98059, suppressed DFO-induced cell migration and invasion. CONCLUSION: DFO-induced HIF-1α expression involves a cascade of signaling events including ROS generation, activation of ERK signaling, and subsequent promotion of cell migration and invasion. These findings indicate a risk associated with DFO and other iron chelators for treatment of tumors with invasive potential.
Asunto(s)
Movimiento Celular/efectos de los fármacos , Deferoxamina/toxicidad , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Sideróforos/toxicidad , Línea Celular Tumoral , Flavonoides/farmacología , Humanos , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteína Quinasa 3 Activada por Mitógenos/metabolismo , NADPH Oxidasas/antagonistas & inhibidores , NADPH Oxidasas/metabolismo , Compuestos Onio/toxicidad , Fosforilación/efectos de los fármacos , ARN Mensajero/metabolismo , Regulación hacia Arriba/efectos de los fármacosRESUMEN
INTRODUCTION: The public interest steadily increases in the biological adverse effects caused by components released from resin-based dental restorations. OBJECTIVE: In this study, the cytotoxicity and the genotoxicity were investigated of following released components from dental resin restorations in human gingival fibroblasts (HGF): tetraethyleneglycol dimethacrylate (TEEGDMA), neopentylglycol dimethacrylate (Neopen), diphenyliodoniumchloride (DPIC), triphenyl-stibane (TPSB) and triphenylphosphane (TPP). METHODS: XTT based cell viability assay was used for cytotoxicity screening of substances. γ-H2AX assay was used for genotoxicity screening. In the γ-H2AX assay, HGFs were exposed to the substances for 6h. Induced foci represent double DNA strand breaks (DSBs), which can induce ATM-dependent phosphorylation of the histone H2AX. Cell death effects (apoptosis and necrosis), induced by the substances were visually tested by the same investigator using the fluorescent microscope. RESULTS: All tested substances induced a dose-dependent loss of viability in HGFs. Following toxicity ranking among the substances at EC50-concentration were found in the XTT assay (mM, mean±SEM; n=5): DPIC>Neopen>TPSB>TPP>TEEGDMA. DSB-foci per HGF-cell were obtained, when HGFs were exposed to the EC50-concentration of each substance in the following order (mean±SEM; n=3): DPIC>Neopen>TPSB>TPP>TEEGDMA. Multi-foci cells (cells that contain more than 40 foci each) in 80 HGF-cells at EC50-concentration of each substance were found as follow (mean±SEM; n=3): DPIC>Neopen>TPP>TPSB>TEEGDMA. Cell apoptosis contained in each substance at EC50-concentration in the following order (mean±SEM; n=3): DPIC>Neopen>TPSB>TPP >TEEGDMA. Cell necrosis contained in each substance at EC50-concentration in the following order (mean±SEM; n=3): DPIC>Neopen>TPSB>TPP>TEEGDMA. CONCLUSION: Leached components from dental resin restorations can induce DNA DSBs and cell death effects in HGFs.
Asunto(s)
Resinas Compuestas/toxicidad , Roturas del ADN de Doble Cadena/efectos de los fármacos , Materiales Dentales/toxicidad , Fibroblastos/efectos de los fármacos , Encía/efectos de los fármacos , Apoptosis/efectos de los fármacos , Compuestos de Bifenilo/toxicidad , Técnicas de Cultivo de Célula , Línea Celular , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Encía/citología , Histonas/efectos de los fármacos , Humanos , Indicadores y Reactivos , Ensayo de Materiales , Metacrilatos/toxicidad , Microscopía Fluorescente , Mutágenos/toxicidad , Necrosis , Compuestos Onio/toxicidad , Compuestos Organofosforados/toxicidad , Polietilenglicoles/toxicidad , Ácidos Polimetacrílicos/toxicidad , Estilbenos/toxicidad , Sales de TetrazolioRESUMEN
Occurrence of macrophage apoptosis has been implicated for the altered immune function found in an opiate milieu. In the present study, we evaluated the role of oxidative stress in morphine-induced macrophage apoptosis. Morphine promoted the apoptosis of macrophages. This effect of morphine was associated with the production of superoxide and nitric oxide (NO). Antioxidants provided protection against morphine-induced macrophage injury. In addition, diphenyleneiodonium chloride, an inhibitor of reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation, attenuated the proapoptotic effect of morphine. Antitransforming growth factor-beta (anti-TGF-beta) antibody and propranolol (an inhibitor of the phospholipase D pathway) inhibited morphine-induced superoxide generation as well as apoptosis. N'-Tetraacetic acid tetra (acetoxymethyl) ester, a calcium-chelating agent, inhibited morphine-induced apoptosis, whereas thapsigargin (a calcium agonist) stimulated macrophage apoptosis under basal as well as morphine-stimulated states. These studies suggest that morphine-induced macrophage apoptosis is mediated through downstream signaling involving TGF-beta and NO production. Moreover, there is NADPH oxidation activation involving phospholipase D and Ca(2+), leading to the generation of superoxide. In in vivo studies, administration of N-acetyl cysteine and preinduction of heme oxygenase activity and epoetin alpha prevented morphine-induced peritoneal macrophage apoptosis, thus further confirming the role of oxidative stress in morphine-induced macrophage apoptosis.
Asunto(s)
Apoptosis/efectos de los fármacos , Macrófagos Peritoneales/patología , Morfina/farmacología , Narcóticos/farmacología , Estrés Oxidativo/efectos de los fármacos , Superóxidos/metabolismo , Animales , Ansiolíticos/farmacología , Antioxidantes/farmacología , Calcio/metabolismo , Activación Enzimática/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Epoetina alfa , Eritropoyetina/metabolismo , Hemo Oxigenasa (Desciclizante)/metabolismo , Macrófagos Peritoneales/metabolismo , Ratones , NADPH Oxidasas/antagonistas & inhibidores , Óxido Nítrico/metabolismo , Compuestos Onio/toxicidad , Fosfolipasa D/antagonistas & inhibidores , Propranolol/farmacología , Proteínas Recombinantes , Tapsigargina/farmacología , Factor de Crecimiento Transformador beta/antagonistas & inhibidores , Factor de Crecimiento Transformador beta/inmunologíaRESUMEN
A boronated derivative of dequalinium, a delocalized lipophilic cation (DLC), was synthesized as a potential boron carrier for the selective targeting of mitochondria in malignant versus benign cells for boron neutron capture therapy (BNCT), a binary modality for the treatment of cancer. This agent, designated DEQ-B, was taken up and retained in vitro in the KB, F98, and C6 tumor cell lines but not in the normal epithelial cell line CV1. DEQ-B was also less toxic in the latter cell line at lower exposure concentrations The uptake, retention, and toxicity profiles of DEQ-B are comparable to those of the non-boronated DLCs, dequalinium, MKT 077, RH 123, and tetraphenylphosphonium chloride. Our results suggest that the synthesis and further evaluation of boronated DLCs as potential delivery agents for BNCT is warranted.
Asunto(s)
Terapia por Captura de Neutrón de Boro/métodos , Decualinio/análogos & derivados , Animales , Antineoplásicos/farmacocinética , Antineoplásicos/toxicidad , Boranos/síntesis química , Boranos/farmacocinética , Boranos/toxicidad , Neoplasias Encefálicas/metabolismo , Línea Celular , Chlorocebus aethiops , Decualinio/farmacocinética , Decualinio/toxicidad , Portadores de Fármacos , Células Epiteliales/metabolismo , Glioma/metabolismo , Humanos , Células KB/metabolismo , Compuestos Onio/farmacocinética , Compuestos Onio/toxicidad , Compuestos Organofosforados/farmacocinética , Compuestos Organofosforados/toxicidad , Piridinas/farmacocinética , Piridinas/toxicidad , Ratas , Ratas Endogámicas F344 , Rodamina 123/farmacocinética , Rodamina 123/toxicidad , Tiazoles/farmacocinética , Tiazoles/toxicidad , Células Tumorales CultivadasRESUMEN
o,o'-Diphenylenehalonium (DPH) cations represent a novel class of DNA-affinic compounds characterized by binding constants within the range of 10(5)-10(6) M(-1). The maximum binding capacity of 2-2.5 base pairs per DPH cation and about 30% hypochromic reduction in the optical absorption of DPH cations upon binding to DNA suggest intercalation as a likely binding mode. In a DNA-bound form, DPH cations induce strand breaks upon reduction by radiation-produced electrons in aqueous solutions. In keeping with this mechanism, the cleavage is strongly inhibited by oxygen and is not affected by OH radical scavengers in the bulk. The yields of DPH-mediated base release significantly exceed the yield of base release caused by hydroxyl radical (in the absence of scavenger) in anoxic solutions. The yields are weakly dependent on DNA loading within the range from 5 to 50 base pairs per intercalator, which indicates the ability of excess electrons in DNA to react with a scavenger separated by tens of base pairs from the electron attachment site. The question regarding the mechanism by which the distant reactants reach each other in DNA remains unanswered, although it most likely involves electron hopping rather than a single-step long-distance tunneling. The latter conclusion is based on our finding that the electron affinity of DPH cations does not affect their properties as electron scavengers in DNA as would be expected if the direct long-distance tunneling is involved.
Asunto(s)
Daño del ADN , ADN/efectos de los fármacos , Sustancias Intercalantes/toxicidad , Compuestos Onio/toxicidad , Cationes/toxicidad , Cromatografía Líquida de Alta Presión , ADN/química , Electrones , Depuradores de Radicales Libres/farmacología , Cromatografía de Gases y Espectrometría de Masas , Radical Hidroxilo/metabolismo , Soluciones , AguaRESUMEN
Highly sensitive and convenient analysis of intracellular cationic drugs has been achieved by applying matrix-assisted laser desorption/ionization mass spectrometry (MALD-MS). Tetraphenylphosphonium cation was readily identified and quantified (using methyltriphenylphosphonium cation as an internal standard) at subpicomole levels in crude lysate from < 4 x 10(3) FaDu human hypopharyngeal carcinoma cells. A quantitative MALD-MS time course for tetraphenylphosphonium cation accumulation into FaDu cells was comparable to a time course using scintillation counting with tritiated tetraphenylphosphonium. MALD-MS was also capable of demonstrating the reduced accumulation of the cationic drug rhodamine-123 by DoxR MCF7, a multiply drug-resistant human breast adenocarcinoma cell line, relative to the nonresistant parent line MCF7. In addition, MALD-MS was used to follow a chemical reaction inside intact FaDu cells: the formation of a hydrazone (II-51) from benzaldehyde and an acylhydrazide, 5-[tris(4-dimethylaminophenyl)phosphonio]pentanoyl hydrazide (II-25). These results suggest that MALD-MS may provide a rapid and practical alternative to existing methods for the analysis of cationic drugs, toxins, and their metabolites in cells and tissues.
Asunto(s)
Resistencia a Medicamentos/fisiología , Compuestos Onio/metabolismo , Compuestos Organofosforados/metabolismo , Compuestos de Tritilo/metabolismo , Adenocarcinoma , Benzaldehídos/química , Benzaldehídos/metabolismo , Benzaldehídos/toxicidad , Transporte Biológico , Neoplasias de la Mama , Carcinoma de Células Escamosas , Cationes , Línea Celular , Doxorrubicina/toxicidad , Femenino , Humanos , Neoplasias Hipofaríngeas , Cinética , Rayos Láser , Espectrometría de Masas/métodos , Estructura Molecular , Compuestos Onio/química , Compuestos Onio/toxicidad , Compuestos Organofosforados/química , Compuestos Organofosforados/toxicidad , Relación Estructura-Actividad , Compuestos de Tritilo/química , Compuestos de Tritilo/toxicidad , Células Tumorales CultivadasRESUMEN
The antiarrhythmic actions of 3,6-dimethylamino-dibenzopyridonium edetate (IHC-72), lidocaine (Lid) and verapamil (Ver) on several models Were compared at equitoxic doses (equal fraction of LD50). The action of IHC-72 against aconitine induced arrhythmia was similar to that of Lid but stronger than that of Ver in anesthetized rats. The effect of IHC-72 on ouabain induced arrhythmia was also similar to that of Lid, but weaker than that of Ver in anesthetized guinea pigs. The activity of IHC-72 to raise electrical ventricular fibrillation thresholds (VFT) was weaker than that of Lid and Ver. The effects of IHC-72 in decreasing the incidence of ventricular premature beat(VP B), ventricular tachycardia (VT), ventricular fibrillation (VF) and shortening the duration of VT yielded by reperfusion were similar to those of Lid anf Ver in vivo.
Asunto(s)
Antiarrítmicos/uso terapéutico , Arritmias Cardíacas/prevención & control , Ácido Edético/análogos & derivados , Compuestos Onio/uso terapéutico , Aconitina , Animales , Arritmias Cardíacas/inducido químicamente , Arritmias Cardíacas/etiología , Ácido Edético/uso terapéutico , Ácido Edético/toxicidad , Femenino , Cobayas , Lidocaína/uso terapéutico , Masculino , Ratones , Daño por Reperfusión Miocárdica/complicaciones , Compuestos Onio/toxicidad , Ouabaína , Ratas , Ratas Endogámicas , Fibrilación Ventricular/inducido químicamente , Fibrilación Ventricular/prevención & control , Verapamilo/uso terapéuticoRESUMEN
Chronic administration of the NADH-CoQ reductase inhibitor, diphenyleneiodonium to rats at two dose levels, 1.0 and 1.5 mg/kg per day, caused a 40% and 60% reduction, respectively, in the in vitro rate of NAD-linked respiration by skeletal muscle mitochondria. At the highest dose, muscle fatigue, lactic acidosis and an over-utilization of phosphocreatine was observed in the gastrocnemius muscle during mild stimulation of 1 Hz frequency. The resynthesis of phosphocreatine following muscle stimulation was about 2 fold slower in the treated animal group. At the low dose, no significant biochemical changes were observed during muscle stimulation at 4 Hz. The results are discussed in terms of skeletal muscle "oxidative reserve", twitch tension maintenance and the relevance to the human diseased state of mitochondrial myopathy.
Asunto(s)
Mitocondrias Musculares/patología , Músculos/patología , Enfermedades Musculares/inducido químicamente , Compuestos Onio/toxicidad , Quinona Reductasas/metabolismo , Acidosis/inducido químicamente , Animales , Relación Dosis-Respuesta a Droga , Masculino , Mitocondrias Musculares/efectos de los fármacos , Músculos/efectos de los fármacos , Músculos/metabolismo , Enfermedades Musculares/metabolismo , NAD(P)H Deshidrogenasa (Quinona) , Fosfocreatina/metabolismo , Ratas , Ratas Endogámicas , Factores de TiempoRESUMEN
Daily subcutaneous administration of the oral hypoglycaemic agent, diphenyleneiodonium at a low dose (1.5 mg/kg body weight) over a 4-5 week period resulted in a normoglycaemic stable animal model of impaired oxidative phosphorylation in the rat. Diphenyleneiodonium specifically inhibits NAD-linked mitochondrial oxidation [Bloxham, Biochem. Soc. Trans. 7, 103 (1979)], and in isolated mitochondrial preparations from heart, soleus and gastrocnemius muscle and liver from treated animals NAD-linked respiration was reduced by 40% or more of mean control values. Brain and kidney mitochondria isolated from the treated group had similar rates of NAD-linked respiration to their respective control values. The activity of NADH-ferricyanide reductase was significantly reduced in all tissues tested, even in the isolated brain and kidney mitochondria where the activity in these tissues was 60-75% of control values. This suggests that at least 40% of Complex I activity must be inhibited before there is a decline in NAD-linked mitochondrial respiration. This paper discusses the use of diphenyleneiodonium as a means of establishing an animal model of the human disease state, termed mitochondrial myopathy.
Asunto(s)
Hipoglucemiantes/toxicidad , Mitocondrias/metabolismo , Enfermedades Musculares/inducido químicamente , Compuestos Onio/toxicidad , Fosforilación Oxidativa/efectos de los fármacos , Administración Oral , Animales , Citocromos/análisis , Modelos Animales de Enfermedad , Masculino , Mitocondrias/efectos de los fármacos , Músculos/metabolismo , NAD/metabolismo , Complejo Piruvato Deshidrogenasa/análisis , Ratas , Ratas EndogámicasRESUMEN
Three ketophosphonium salts containing a morpholino group were prepared and evaluated for their neuromuscular blocking effect. Solution and crystal conformations were studied. An attempt was made to explain, in structural terms, different activity levels in connection with the interatomic distances.
Asunto(s)
Bloqueantes Neuromusculares/farmacología , Compuestos Onio/farmacología , Animales , Fenómenos Químicos , Química , Dosificación Letal Mediana , Espectroscopía de Resonancia Magnética , Conformación Molecular , Bloqueantes Neuromusculares/síntesis química , Bloqueantes Neuromusculares/toxicidad , Compuestos Onio/síntesis química , Compuestos Onio/toxicidad , Ratas , Relación Estructura-Actividad , Difracción de Rayos XRESUMEN
A new series of cyclic organophosphorus esters, 2-S-[2'-N,N-dialkylamino)ethyl]thio-1,3,2-dioxaphosphorinane 2-oxide and their quaternary derivatives, was synthesized and studied as potential antiglaucoma agents. Thes compounds inhibit acetylcholinesterase (E.C.3.1.1.7)at a bimoecular rate constant (ki) in the range of 10(3)-10(4) M-1 min-1. Values of the affinity (K) and phosphorylation (k') rate constants for this enzyme indicate that k' is responsible for the relatively low values of ki as compared with similar data for the open-chain analogues, O,O-diethyl phosphorothiolates (10(6) M-1 min-1). The mammalian toxicity of the new compounds in terms of acute LD50 values in mice is 1-3 x 10(3) less than that of phospholine, an open-chain analogue. In an initial clinical trial, one member of the new series (alkyl = C2H5) caused a significant decrease of intraocular pressure in aphakic glaucoma, while phospholine proved to be ineffective.