ObjectiveTo study the effects of aminoguanidine (AG), a selective inhibitor of inducible nitric oxide synthase (iNOS) on the pathological changes of liver tissues and ultrastructural changes of liver cells in rodent model of endotoxic shock. MethodsTwentyfour male Wistar rats were randomly divided into normal control group，lipopolysaccharide (LPS) control group and AG treatment group, each group had 8 rats. Rats were challenged by E.coli LPS to set up the model of endotoxic shock, AG group were treated by aminoguanidine. The pathological and ultrastructural changes of liver tissues and plasma NO contents of three groups were observed and compared. ResultsLight microscopy revealed that many tiny abscesses scattered in liver tissue in LPS group, accompanied by necrosis of liver cells and neutrophils infiltration, while liver injuries of AG group were much slighter than that in LPS group. Electron microscopy revealed that there were dissolved plaques in hepatocyte nuclears, swelling of mitochondria, decreasing in number of mitochondrial ridges, while AG play a protective role to nuclears and mitochondria of hepatocytes. The plasma NO levels of LPS control group were higher than that of normal control group, and plasma NO levels decreased significantly after AG treatment, but still higher than that of normal control group. Conclusion Aminoguanidine selectively inhibits iNOS activity and prevents the overproduction of NO induced by iNOS, thus attenuates the damages of liver structure induced by NO. This method has potential value in clinical application, which deserves more deep research.
Objective To study the effects on MCF-7 breast cancer cells with combination of tamoxifen（TAM） and antisense oligonucleotide （ASODN） targeting survivin mRNA. Methods MCF-7 breast cancer cells were treated with a 20 mer ASODN targeting survivin mRNA and TAM, which were divided into three groups: TAM group (treated by TAM only), ASODN group (by ASODN only), and TAM+ASODN combined group (by TAM+ASODN combination). The growth inhibition of MCF-7 cells, the changes of cell cycles and apoptotic rate, the positive rate of survivin mRNA expression, and the activity of caspase-3 were tested by MTT, flow cytometry, hybridization in situ, and spectrophotometric method, respectively.Results The rate of growth inhibition of MCF-7 cells in the TAM+ASODN combined group was (62.26±3.92)%, which was significantly higher than that in the TAM group 〔(42.30±6.63)%〕 or ASODN group 〔(54.77±9.99)%〕, Plt;0.05. The apoptotic rate of MCF-7 cells was (28.08±4.32)% in the TAM+ASODN combined group, which was significantly higher than that in the TAM group 〔(18.94±4.01)%〕 or ASODN group 〔(21.12±3.95)%〕, Plt;0.01. The effect of arresting MCF-7 cells in G0/G1 phase in the TAM+ASODN combined group was ber than that in the TAM or ASODN group (Plt;0.05, Plt;0.01). The positive rate of survivin mRNA in the TAM+ASODN combined group was (13.38±3.45)%, which was significantly lower than that in the TAM group 〔(39.67±7.42)%〕 or ASODN group 〔(27.50±5.80)%〕, Plt;0.01. The activity of caspase-3 in the TAM+ASODN combined group （0.93±0.13） was significantly higher than that in the TAM group (0.50±0.09) or ASODN group (0.64±0.08), Plt;0.01. Conclusion The ASODN targeting survivin mRNA can promote the apoptosis of MCF-7 breast cancer cells, and make MCF-7 cells more sensitive to tamoxifen.