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Cell Electrophoresis (cell + electrophoresis)
Selected AbstractsMeasurement of electrophoretic mobility of cardiomyocytesELECTROPHORESIS, Issue 21 2009Ying Zhou Abstract The electrophoretic mobility (EPM) of rat cardiomyocytes with or without the treatment of neuraminidase was studied by cell electrophoresis. The EPM was found to change over a range from 0 to 8.67,,m,s,1/V,cm,1, depending on ionic strength, transmembrane potential, pH value, and/or surface charges. It is interesting that zero EPM was observed but reverse of the mobility was not. These results suggested that the negative charges carried on the cardiomyocyte surface might comprehensively consist of surface sialic acid, plasmalemma proteins, phospholipids, and transmembrane potential. The aberrant electrical double layer formed between the carried negative charges and adions had a big adsorption layer and a diffusion layer whose sizes changed circularly, making only negative charges be carried on the surface of living cardiomyocytes. The special structures on the surface of cardiomyocytes probably play a considerable role in the process of cardiac electrical activity. [source] Antioxidant Defenses and DNA Damage Induced by UV-A and UV-B Radiation in the Crab Chasmagnathus granulata (Decapoda, Brachyura),PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 2 2005Glauce R. Gouveia ABSTRACT The photoprotector role of pigment dispersion in the melanophores of the crab, Chasmagnathus granulata, against DNA and oxidative damages caused by UV-A and UV-B was investigated. Intact and eyestalkaless crabs were used. In eyestalkless crabs, the dorsal epidermis of the cephalothorax (dispersed melanophores) and the epidermis of pereiopods (aggregated melanophores) were analyzed. Intact crabs showed only dispersed melanophores in the two epidermis. Antioxidant enzymes activity and lipoperoxidation content were analyzed after UV-A (2.5 J/cm2) or UV-B (8.6 J/sm2) irradiation. DNA damage was analyzed by single cell electrophoresis (comet) assay, after exposure to UV-B (8.6 J/cm2). UV-A radiation increased the glutatione- S -transferase activity in the pereiopods epidermis of eyestalkless crabs (P < 0.05). UV-B radiation induced DNA damage in the dorsal epidermis of eyestalkless crabs (P < 0.005). In pereiopod epidermis of eyestalkless crabs, there was no significant difference between control and UV-B-exposed crabs. In the pereiopods epidermis of eyestalkless, the control group showed higher scores of DNA damage and ,50% of cellular viability. Because in eyestalkless and irradiated crabs the cellular viability was ,5%, it was not possible to observe nuclei for determination of DNA damage. The findings show that melanophores can play a role in the defense against harmful effects of a momentary exposure to UV radiation. [source] Heroin-Administered Mice Involved in Oxidative Stress and Exogenous Antioxidant-Alleviated Withdrawal SyndromeBASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 2 2006Bo Xu It is well known that an increase in DA oxidative metabolism leads to increased reactive oxygen species (ROS) formation, and thus, ROS have been frequently associated with neuronal cell death due to damage to carbohydrates, amino acids, phospholipids, and nucleic acids. This study investigated whether there are oxidative stress and effects of exogenous antioxidants in heroin-administered mice. The heroin-dependent mice model was made via intraperitoneal injection. Oxidative damage of DNA, protein, and lipid was measured by analysis of single cell electrophoresis, the 2,4-dinitrophenylhydrazine method, and thiobarbituric acid method respectively. The activities of antioxidative enzymes and total antioxidant capacity were assayed by spectrophotometry. After administration with heroin, the mice not only showed decrease of total antioxidant capacity in serum and antioxidant enzymes such as superoxide dismutase, catalase, and glutathione (GSH) peroxidase in brain, but also exhibited the oxidative damages of DNA, protein and lipid. On the other hand, exogenous antioxidants could restrain the oxidative stress, even alleviate withdrawal syndrome in heroin-administered mice. Our results also imply a possibility that ROS may participate in the whole process of dependence and withdrawal of heroin. Therefore, strategies of blocking oxidative stress may be useful in the development of therapy for opiate abuse. [source] Oxidative Damage of Biomolecules in Mouse Liver Induced by Morphine and Protected by AntioxidantsBASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 2 2004Yun-Tao Zhang The oxidative damage of DNA as measured by single cell electrophoresis and high-performance liquid chromatography equipped with electrochemical and UV detection, the protein carbonyl content was measured by 2,4-dinitrophenylhydrazine method, and the malondialdehyde content was measured by the HPLC method. The activities of antioxidative enzymes, superoxide dismutase, catalase and glutathione peroxidase, and the activity of alanine aminotransferase were assayed by spectrophotometer method. Glutathione and oxidized glutathione were detected by fluorescence spectrophotometer method. All the indexes of oxidative damage, such as 8-OHdG, protein carbonyl group and malondialdehyde content, and the activity of alanine aminotransferase (n=27) increased significantly compared to those of control (n=27) (P<0.01) in livers of morphine-administered alone mice, while the indexes related with the in vivo antioxidative capacity, such as the ratio of glutathione and oxidized glutathione, activities of superoxide dismutase, catalase and glutathione peroxidase significantly decreased (P<0.01). When mice were treated with morphine combined with exogenous antioxidants, glutathione and ascorbic acid, all the indexes of oxidative damage and the activity of alanine aminotransferase showed no changes as compared to those of control (P>0.05), i.e., both glutathione and ascorbic acid completely abolished the damage of morphine on the hepatocyte. These results implied that morphine caused a seriously oxidative stress in mice livers and hence caused hepatotoxicity, while exogenous antioxidants were able to prevent the oxidative damage of biomolecules and hepatotoxicity caused by morphine. Thus, blocking oxidative damage may be a useful strategy for the development of a new therapy for opiate abuse. [source] | ||||||||||