ABSTRACT
Objective To study the inhibitory effect of panax notoginseng saponins (PNS) on 3-nitrotyrosine (3-NT) formation in brain induced by heme/NO2 -/H2O2 or ONOO - pathways in vitro. Methods According to the two major pathways of 3-NT formation in vivo, the models of protein nitration induced by heme/NaNO2/H2O2 or ONOO-system were established, respectively, in vitro. Bovine serum albumin (BSA)/rat plasma protein or rat brain homogenate protein were utilized as reactive substrates in both systems. Samples were divided into blank-control group, 3-NT group and PNS group (including low-, medium-and high-concentration subgroups). In 3-NT group, samples were exposed to heme/NaNO2/H2O2 or ONOO-system, respectively, at 37℃for 30 min, whereas in PNS group, samples were pre-incubated with PNS (at final concentrations of 50 mg/L, 100 mg/L, and 200 mg/L) at 37℃for 5 min before the nitrating system exposure. The 3-NT level in each group was detected by Western blot assy. Results Compared with the blank-control group, both heme/NaNO2/H2O2 and ONOO-system can induce significant 3-NT generation in BSA/rat plasma protein or rat brain homogenate protein (P0.05). Medium- and high-concentrations of PNS pre-treatment markedly inhibited 3-NT accumulation, with maximum effect at the concentration of 200 mg/L (P<0.05). Conclusion Medium- and high-concentrations of PNS can inhibit 3-NT formation in brain tissue mediated by either heme/NO2-/H2O2 or ONOO-pathways, implying that potential neuroprotective action against 3-NT involves pathological conditions, like trauma, stroke, and neurodegenerative diseases.
ABSTRACT
[Objective]To observe expression of inducible nitric oxide synthase and peroxynitrite anion around the prostheses,and study the relationship between the osteolysis and inducible nitric oxide synthase peroxyni-trite.[Method]Interface tissues were obtained at three Delee-Charnley acetabular sections and seven Gruen femur sections in six revision total hip arthroplasty surgery. The tissues were prepared for immunohistochemical assays to determine the expression of iNOS and nit rotyrosine (NT)-a specific“footprint”of peroxynitrite. Pre-revision X-ray films were observed to determine the incidence of osteolysis regions and non-osteolysis regions. The correlation between the positive cells and the severity of osteolysis were analyzed and compared.[Result]Data showed that zone Ⅲ has much higher iNOS positive immunostaining than that of zone Ⅰ and Ⅱ at acetabulum, and the expression of zone 1、2、6、7 was significantly higher than the other zone at femur(P
ABSTRACT
An improvement of chemiluminescent system for determination of peroxynitrite anion (ONOO－) has been made. In this system, the effect of some antioxidants for scavenging ONOO－ was tested. The constitute of this system and the program of starting were followed as: The ozone (O3) was bubbled through a glass-frit into 10 ml 0.01 mol/L solution of sodium azide in CB(pH 10.5) to generate ONOO－. The 800 μl ozonized solution of azide was injected into a glass tude in situ which contains 100 μl sample and 100 μl luminol solutions to initiate chemiluminescence (CL). The pluses / 6 seconds (CP6S) were determined immediately and continually for 10～30 times. A certain CL intensity (CP6S) was chosen as evaluation index to compare the activity of antioxidants. This chemiluminescent system is sensible, simple and stable. The determination limit was 8.74 μmol/L ONOO－. The linear rang was 8.74～74.04 μmol/L ONOO－. The intra batch and inter batch variation coefficient (CV%) of the analysis were 3.35%(n=10) and 5.52%(n=10) respectively. It was tested that Vit.C, teapolyphenol, procyanidin and thiourea all have effects on scavenging ONOO－.