RESUMEN
The lining of the uterus and cervix might be injured by a variety of oxidation products of Cu in a Cu-IUD, including cuprous ions, dissolved and precipitated cupric ions, and reactive oxygen species such as superoxide radicals, hydrogen peroxide, and hydroxyl radicals. In this study, the human amnious WISH cell line was employed as a model of uterine cells in the presence of copper. The cell viability was decreased by elemental copper, which was alleviated up to 70% by the addition of catalase. The addition of copper oxychloride caused cell death in a dose-dependent manner. Hydroxyl radicals in the presence of copper were determined by the formation of malondialdehyde. Soluble cuprous chloride complexes are formed in the uterus by slowly entering oxygen. The complexes are partly oxidized to insoluble copper oxychloride. which damages the endometrium. Unoxidized cuprous ions migrate to the oxygen-rich cervix and are oxidized to copper oxychloride, causing cervix damage.
Asunto(s)
Anticoncepción/métodos , Cobre/metabolismo , Radical Hidroxilo/efectos adversos , Dispositivos Intrauterinos de Cobre/efectos adversos , Útero/efectos de los fármacos , Catalasa/química , Línea Celular , Supervivencia Celular/efectos de los fármacos , Cobre/efectos adversos , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Radical Hidroxilo/análisis , Rojo Neutro/química , Oxidación-Reducción , Sustancias Reactivas al Ácido Tiobarbitúrico/análisis , Enfermedades Uterinas/inducido químicamente , Útero/citologíaRESUMEN
O estanho é um agente químico de uso amplamente difundido nos mais diferentes setores da atividade humana, podendo ser encontrado, por exemplo, em preparações biocidas; como conservante em refrigerantes; na composição de cremes dentais e enxagüantes orais (como veiculador de flúor); como agente anticorrosivo na cobertura de outros metais em embalagens metálicas contendo alimentos e na pigmentação de tintas especiais. Na forma de cloreto estanoso (SnCl2), este agente é utilizado como agente redutor do Tecnécio 99m para a obtenção de radiofármacos e outras moléculas de interesse biológico. Uma vez que a literatura apresenta vários efeitos biológicos indesejáveis atribuídos ao SnCl2, este trabalho teve por objetivo avaliar a sua atividade genotóxica, bem como a ação antioxidante de algumas substâncias naturais (cartilagem e boldina), através do bloqueio das lesões produzidas por este sal em plasmídeos e células bacterianas, com o fim de estudar a ação do íon estanoso sobre o DNA. O emprego das técnicas de análise de sobrevivência bacteriana, capacidade transformante, eletroforese em gel de agarose, espectrofotometria de luz ultravioleta e de absorção atômica, reveram que: i) O cloreto estanoso provoca lesões, mediadas pela produção de espécies reativas de oxigênio, tanto in vivo quanto in vitro; ii) os danos induzidos pelo SnCl2 provocam diminuição da capacidade transformante do plamídeo pUC9.1; iii) o número de lesões formadas no DNS é diretamente proporcional ao tempo de incubação com SnCl2; iv)o íon estanoso é capaz de se associar à molécula de DNA, induzindo a geração de espécies reativas de oxigênio próximo ao local de ligação, promovendo modificações na estrutura da macromolécula; v) essa associação parece acarretar um ataque preferencial às bases nitrogenadas, fato que poderia estar associado a uma potencialidade mutagênica do estanho
Asunto(s)
Compuestos Orgánicos de Estaño/efectos adversos , ADN , Especies Reactivas de Oxígeno , Radicales Libres/efectos adversos , Radical Hidroxilo/efectos adversos , Óxido Nítrico/efectos adversos , Peróxido de Hidrógeno/efectos adversos , Superóxidos/efectos adversos , Compuestos de Estaño/efectos adversos , Estaño/efectos adversosRESUMEN
1. The hypothesis that the hydroxyl ion free radical, HO; derived from O2 plays a pivotal role in the development of reperfusion ventricular fibrillation was tested in 63 anesthetized mongrel dogs of either sex weighing 14 +/- 7 kg submitted to 90-min coronary occlusion followed by 60-min reperfusion. 2. OH. was blocked by the iron chelator deferoxamine (DF, 500 mg) and by dimethylthiourea (DMTU, 500 mg/kg), a HO. scavenger both given iv over 30 min before reperfusion. 3. The frequency of reperfusion ventricular fibrillation was similar in all animals, i.e., 7/27 (26%) control dogs, 7/23 (30%) DF-treated dogs and 3/13 (23%) DMTU-treated dogs. Arterial pressure, heart rate and double product were not significantly different among the three groups during occlusion or reperfusion. The hemodynamic variables were also similar among dogs that fibrillated and those that did not. Likewise, extent of ischemic areas and necrosis was similar among the three experimental groups, with the control values being 34 +/- 4% and 14 +/- 5%, respectively. 4. We conclude that OH. does not play a major role in the induction of reperfusion ventricular fibrillation in the anesthetized dog with ischemia/necrosis.
Asunto(s)
Radical Hidroxilo/efectos adversos , Reperfusión Miocárdica/efectos adversos , Fibrilación Ventricular/etiología , Anestesia , Animales , Deferoxamina/farmacología , Perros , Femenino , Depuradores de Radicales Libres , Hemodinámica/efectos de los fármacos , Masculino , Tiourea/análogos & derivados , Tiourea/farmacologíaRESUMEN
1. The hypothesis that the hydroxyl ion free radical, HO; derived from O2 plays a pivotal role in the development of reperfusion ventricular fibrillation was tested in 63 anesthetized mongrel dogs of either sex weighing 14 +/- 7 kg submitted to 90-min coronary occlusion followed by 60-min reperfusion. 2. OH. was blocked by the iron chelator deferoxamine (DF, 500 mg) and by dimethylthiourea (DMTU, 500 mg/kg), a HO. scavenger both given iv over 30 min before reperfusion. 3. The frequency of reperfusion ventricular fibrillation was similar in all animals, i.e., 7/27 (26 per cent ) control dogs, 7/23 (30 per cent ) DF-treated dogs and 3/13 (23 per cent ) DMTU-treated dogs. Arterial pressure, heart rate and double product were not significantly different among the three groups during occlusion or reperfusion. The hemodynamic variables were also similar among dogs that fibrillated and those that did not. Likewise, extent of ischemic areas and necrosis was similar among the three experimental groups, with the control values being 34 +/- 4 per cent and 14 +/- 5 per cent , respectively. 4. We conclude that OH. does not play a major role in the induction of reperfusion ventricular fibrillation in the anesthetized dog with ischemia/necrosis