ABSTRACT
Objective To explore the in vivo killing effects of nanosecond pulsed electric fields on mouse breast cancer in tumor bearing BALB/c mice. Methods Twenty four BALB/c mice models with subcutaneous EMT-6 breast cancer were prepared and divided into experimental group and control group (n=12). In experimental group, the mice were treated by the pulsed electric fields with peak voltage of 700 V/cm, rise times of 57 ns, durations of 70μs and duty ratio of 50%on the tumor tissue with two parallel electrodes under anaesthesia. One hundred pulses were given and the energy was just 9.75 J with effective action period of 7 ms. Tumor volume, animal weight and histopathologic changes after 1, 3, 5 and 7 d were observed after irreversible electroporation. Results The tumor volume in experimental group increased more slowly than that in control group, especially at the 1-3 d after treatment with a standstill. Histopathological examination results showed that the tumor tissue had obvious coagulation necrosis and tissue edema after electrical stimulation treatment, and mass vacuole like structure appeared in tumor tissue from the third day after treatment and vascular injury occurred at the early stage. Conclusions In the given field conditions, steep pulsed electric field has inhibitory effect on tumor growth. In order to achieve more ideal tumor therapy effect, further studies on steep pulse dose are needed.
ABSTRACT
The purpose of the present study was to elucidate the cytotoxical influence of mercurial compounds and the protective effect of selenium against mercurial compounds. The effects of mercury compounds and selenium on the syntheses of nitrite(NO2-) and ATP were observed in the cell cultures of EMT-6 cells and peritoneal macrophages from Balb/c mouse. The viabilities of EMT-6 cells and peritoneal macrophages at the end of culture were significantly decreased in dose-dependent manner by methylmercury chloride (CH3HgCl) added into the media. NO2- and ATP syntheses of the cells were dose-dependently inhibited by CH3HgCl. Simultaneous addition of the equimolar dose of selenium completely prevented mercury-induced inhibitions of NO2- and ATP syntheses, which were observed in both of EMT-6 cells and peritoneal macrophages. But these effects of selenium were not appeared in the new medium containing mercurials only which were removed the selenium after the pretreatment of selenium for 6 hours. These results suggest that protective effect of selenium against mercurial compounds was archived by the formation of a complex consisting of Se-Hg or Se-Hg-protein. Though its mechanism was not clear, the protective role of selemium against the mercury toxicity would be exhibited in the immunological system.
Subject(s)
Animals , Mice , Adenosine Triphosphate , Cell Culture Techniques , Macrophages, Peritoneal , Mercury Compounds , Nitric Oxide , SeleniumABSTRACT
The effects of treatment with mercury chloride on the nitrite and nitrate syntheses were observed in peritoneal macrophages from Balb/c mice and EMT-6 cells in vitro. The cells were cultured in Dulbecco's modified Eagle's medium(DMEM) with cytokines. Amounts of nitrite and nitrate in the culture media after 24 and 36 hours of culture were about 2-fold, and 3-fold of those measured after 12 hours respectively. There were very close associations between the amounts of nitrite and nitrate measured in the culture media according to culture time. The survival rate of peritoneal macrophages was significantly decreased by mercury chloride added into the media in dose-dependent manner, however the survivals of EMT-6 cells were not influenced by mercury chloride concentration in media. Nitrite and nitrate syntheses were dose-dependently decreased by mercury chloride added in culture media. ATP synthesis also decreased in EMT-6 cells by mercury chloride. These results reported here suggest that the disorder of cell mediated immunity by mercurials could be related to the inhibition of nitric oxide synthesis which seems to be caused by the inhibition of ATP synthesis.
Subject(s)
Animals , Mice , Adenosine Triphosphate , Culture Media , Cytokines , Immunity, Cellular , Macrophages , Macrophages, Peritoneal , Nitric Oxide , Survival RateABSTRACT
The effects of several factors on the nitrite synthesis were observed in the culture of EMT-6 cells which are originated from mammary adenocarcinoma of Balb/c mouse. The cells were cultured in Dulbecco's Modified Eagle's Medium containing 10% fetal calf serum. Amounts of nitrite in the culture media after 24 and 36 hours of culture were about 2 fold, and 3-fold of those measured after 12 hours respectively. There were very close associations between the amounts of nitrite measured in the culture media. A significant nitrite synthesis by EMT-6 cells occurred when IL-1 was added to the culture medium with other cytokines as IFN gamma or TNF alpha . One of each cytokines were less effective as an inducer of nitrite than the combinations of cytokines. When mercury chloride or cinnamate was added in the culture medium, the nitrite synthesis was dose-dependently decreased by the concentration of these materials. The viability of EMT-6 cells were kept on 95% or above in 36 hours after beginning of culture without any specific additives except cytokines. While after 48 hours it went down to 85% or less. These viability were decreased by the prolongation of culture time (48 hours or more), the addition of TNF alpha to cytokine mixture, and the higher concentrations of mercury chloride or cinnamate to culture medium. Simultaneous addition of the equimolar dose of selenium completely prevented mercurial compounds-induced inhibitions of nitrite syntheses. But the single addition of selenium neither influenced the viability of cells nor the productions of nitrite. These results suggests that the disorder of cell mediated immunity by mercurial compounds could be related to the inhibition of nitric oxide synthesis and selenium decreased the cytotoxicity of mercurial compounds.
Subject(s)
Animals , Mice , Adenocarcinoma , Culture Media , Cytokines , Immunity, Cellular , Interleukin-1 , Nitric Oxide , SeleniumABSTRACT
The effects of glucose on the productions of ATP and nitrite which are inhibited by mercury compounds, were examined in a cell culture system of RAW 264.7 cells. The cells were cultured in Dulbecco's Modified Eagle's medium (DMEM) with cytokines, IL-1 and TNF for 24 hours. The viablility of RAW 264.7 cells at the end of culture was significantly decreased by mercury chloride or methylmercury chloride added into the media in dose-dependent manner, however the viability of RAW 264.7 cells were influenced in the concentrations lese than 0.8micrometer of mercury chloride or 0.4micrometer of methylmercury chloride. The addition of 4.5 g/l glucose to normal DMEM lowered the pH of media to the range of 6.7-6.8 after 48 hours of culture, but not for the cell survivals. This supplement of glucose to the media also prevented the inhibitions of ATP and nitrite syntheses which were caused by mercurial compounds. These results suggest that the disorder of cell mediated immunity by mercurials could be related to the inhibition of nitric oxide synthesis which seams to be caused by the inhibition of ATP synthesis, especially related to the citric acid cycle.
Subject(s)
Adenosine Triphosphate , Cell Culture Techniques , Cell Line , Citric Acid Cycle , Cytokines , Glucose , Hydrogen-Ion Concentration , Immunity, Cellular , Interleukin-1 , Mercury Compounds , Nitric OxideABSTRACT
The effect of treatment of mercury chloride on the nitrite and nitrate synthesis was observed in peritoneal macrophages from Balb/c mice and EMT-6 cells in vitro. The cells were cultured in Dulbecco's modified Eagle's medium (DMEM) with cytokines. Amounts of nitrite and nitrate in the culture media after 24 and 36 hours of culture were about 2-fold, and 3-fold of those measured after 12 hours respectively. There were very close associations between the amounts of nitrite and nitrate measured in the culture media, according to culture time. The survival rate of peritoneal macrophages was significantly decreased by mercury chloride added into the media in dose-dependent manner, however the survivals of EMT-6 cells were not influenced by mercury chloride concentration in media. Nitrite and nitrate syntheses were dose-dependently decreased by mercury chloride added in culture media. These results reported here suggest that the disorder of cell mediated immunity by mercurials could be related to the inhibition of nitric oxide synthesis which seems to be caused by the inhibition of metabolism of cells.
Subject(s)
Animals , Mice , Culture Media , Cytokines , Immunity, Cellular , Macrophages, Peritoneal , Metabolism , Nitric Oxide , Survival RateABSTRACT
The effect of treatment of mercury chloride on the nitrite and nitrate synthesis was observed in peritoneal macrophages from Balb/c mice and EMT-6 cells in vitro. The cells were cultured in Dulbecco's modified Eagle's medium (DMEM) with cytokines. Amounts of nitrite and nitrate in the culture media after 24 and 36 hours of culture were about 2-fold, and 3-fold of those measured after 12 hours respectively. There were very close associations between the amounts of nitrite and nitrate measured in the culture media, according to culture time. The survival rate of peritoneal macrophages was significantly decreased by mercury chloride added into the media in dose-dependent manner, however the survivals of EMT-6 cells were not influenced by mercury chloride concentration in media. Nitrite and nitrate syntheses were dose-dependently decreased by mercury chloride added in culture media. These results reported here suggest that the disorder of cell mediated immunity by mercurials could be related to the inhibition of nitric oxide synthesis which seems to be caused by the inhibition of metabolism of cells.