ABSTRACT
Objective To apply nitric oxide(NO) electrochemical microsensor in the real time detection of NO released from RAW 264 .3 cells infected by E .coli ,and to explore the application value of this NO microsensor in the research area of infection im‐munity against bacterium .Methods Taking NO microsensor to detect NO released from RAW 264 .3 cells respectively stimulated by E .coli of different densities and of 1 × 107 mL -1 for different time .Results The level of NO released from RAW 264 .3 cells was enhanced obviously when incubated with E .coli as compared with that of normal cells and the extent of incersase depended on the density of E .coli (P<0 .01) .The released level of NO increased gradually from the beginning and reached its peal at the time of 12 h then decreased slowly when incubated with E .coli of 1 × 107 mL -1 .Conclusion The electrochemical microsensor was applied in the real time detection of NO released from macrophages activated by E .coli successfully .
ABSTRACT
In order to investigate the effect of vitamin A (VA) on the secretion of IFN-gamma and IL-4 in Mycoplasma Pneumoniae (MP)-induced A549 cells, A549 cells were co-cultured with MP for different time lengths and then the levels of IFN-gamma and IL-4 in the cell culture supernatants were detected before and after treatment with different concentrations of VA by using the enzyme-linked immunosorbent assay (ELISA). The results showed that the level of IFN-gamma and IL-4 in the supernatants of MP-induced A549 cells was much higher than that in non-induced cells (P<0.01). After application of VA, IL-4 level was not increased until the concentration of VA was up to 0.5x10(-5) mol/L (P<0.01). However, with concentration of VA increased up to 1x10(-4) mol/L, IL-4 was significantly suppressed (P<0.01). It was concluded that MP could induce the secretion of IFN-gamma and IL-4 in A549 cells. VA could inhibit the secretion of IFN-gamma and increase the IL-4 level in MP-induced A549 cells. However, high concentration of VA had an inhibitory effect on the secretion of IL-4 as well as on the IFN-gamma. These data provided a theoretical basis for the application of VA in MP pneumonia in the clinical practice.