ABSTRACT
AIM:To investigate the protective effect of Zhenrenyangzang decoction (ZRYZ) on the intestinal mucosal barrier function and the expression of tight junction proteins,zonula occludens-1 (ZO-1) and occludin,in the co-lon of rats with trinitrobenzenesulfonic acid (TNBS)-induced ulcerative colitis in order to explore the possible mechanism involved. METHODS:Male Wistar rats were randomly divided into normal group, model group, salazosulfapyridine (SASP) positive control group,high-dose ZRYZ(ZRYZ-H) group and low-dose ZRYZ(ZRYZ-L) group. Except the nor-mal group,the rats in other groups were given the TNBS/50% ethanol mixed solution by enema to make the ulcerative coli-tis model. The rats in positive control group were given SASP suspension liquid. The rats in ZRYZ-H group and ZRYZ-L group were orally administered with ZRYZ at doses of 30.4 g/kg and 15.2 g/kg, respectively, while the rats in normal group and model group were orally administered with saline. All the drugs were administered to the rats for consecutive 21 d. Disease activity index (DAI) was investigated during the drug treatment, and colon samples were collected after drug administration for evaluating morphological damage score. Intestinal mucosal permeability was measured by detection of lac-tulose/mannitol (L/M) in urine. Colonic myeloperoxidase(MPO) activity and goblet cell number,serum diamine oxidase (DAO) and D-lactic acid (D-LA) levels, and the colonic expression of ZO-1 and occludin were also measured. RE-SULTS:Compared with normal group,DAI,morphological damage score,L/M value,colonic MPO activity as well as se-rum D-LA and DAO levels in model group significantly increased(P<0.05),while goblet cell number as well as the ex-pression levels of ZO-1 and occludin in model group were significantly reduced(P<0.05). Compared with model group, DAI,morphological damage score,L/M value,colonic MPO activity as well as serum DAO and D-LA levels in ZRYZ-H group and ZRYZ-L group were reduced significantly(P<0.05),while goblet cell number as well as the expression of ZO-1 and occludin in ZRYZ-H group and ZRYZ-L group increased significantly(P<0.05). CONCLUSION:ZRYZ protects the intestinal mucosal barrier function in ulcerative colitis rats by reducing intestinal mucosal permeability,and its mecha-nisms may be related to increasing the expression of ZO-1 and occludin.
ABSTRACT
The isotopic fingerprints of plutonium are extremely important for nuclear safeguards and nuclear forensics. An analytical method was developed for direct determination of 240 Pu / 239 Pu ratio in plutonium-containing particles by laser ablation multiple collector inductively coupled plasma mass spectrometry ( LA-MC-ICP-MS). The risk of ablated particles leakage was reduced by leak detection, exhaust hood, and swiping the laser cell. Scanning mobility particle sizer (SMPS) was used to measure the effect of ablation parameters on the size distribution of ablated particles. The results showed that the majority of ablation material presented as particles from 40 -500 nm and the sweep time after laser ablation should be longer than 15 min. The particle size was evaluated to guide LA-MC-ICP-MS system. By using external normalization method for correction of the mass fractionation correction factor and ion counter efficiencies measured by nebulizer-coupled MC-ICP-MS, a LA-MC-ICP-MS method was established for analysis of 239 Pu / 240 Pu ratio in plutonium particles. Spot size, ablation rate and laser dwell time were set at 30 μm, 5 Hz and 5 s, respectively. Laser energy density was controlled to ensure that the intensities of 239 Pu for plutonium-containing particles were about 2×104 cps and 2×105 cps, respectively. The analytical results showed that the relative uncertainties for 239 Pu / 240 Pu was less than 1. 4% ( n = 6), and the measured value deviated by less than 4. 7% from the reference value. The time for adjusting system and determining 239 Pu / 240 Pu ratio in single plutonium particle was 9 h and 0. 5 h, respectively. The results demonstrated that this technique was rapid, precise and accurate, and could be used for determination of 239 Pu / 240 Pu in plutonium-containing particles.