ABSTRACT
Objective To explore the effect of sodium arsenite (iAs3+) and sodium hydrogen arseuate (iAs5+) exposure on rat multidrug resistance protein 2 (MRP2) expression,and the correlation of liver arsenic and its methylation products,and to provide a basis for further elucidating the mechanism of arsenic toxicity.Methods Seventy wistar rats were randomly divided into seven groups,10 rats in each group.Control group was administrated with deionized water.Sodiun arsenite high-dose group,middle-dose group,low-dose group were administrated with different concentrations of sodium arsenite:20.0,6.7 and 2.2 mg/kg BW every day,respectively.Animals were sacrificed 90 days later by cervical dislocation to collect liver,the expression of MRP2 in the membrane of hepatocyte was determined by Western blotting.HPLC-HGAFS was employed to determine the content or level of arsenic and its methylation products.Correlation between expression of MRP2 and arsenic methylation products was analyzed using Pearson's linear correlation method.Results The MRP2 protein levels of control group,iAs3+ and iAs5+ high-,middle-,low-dose groups were 1.21 ± 0.13,1.85 + 0.09,1.65 + 0.19,1.61 + 0.18,1.69 + 0.04,1.42 + 0.19,1.27 ± 0.10.Compared to control group,MRP2 protein levels of iAs3+ high-,middle-,low-dose group and iAs5+ high-dose group were increased (P ＜ 0.05); Compared with the low-dose group,MRP2 protein levels of iAs3+ and iAs5+ high dose groups were increased(P ＜ 0.05); Comparing the matched doses group of iAs5+ and iAs3+,MRP2 protein levels of iAs3+ high-,middle-,low-dose group were higher than iAs5+(P ＜ 0.05).Meanwhile,there was a significant positive relationship between the expression of MRP2 and the content of iAs3+,MMA and DMA in iAs3+ exposed group(r =0.575,0.678,0.395,all P ＜ 0.05).There was also a significant correlation between the expression of MRP2 and MMA and IMA in iAs5+ exposed group(r =0.593,0.643,all P ＜ 0.05).There was no significant relationship between the expression of MRP2 and the content of iAs5+in iAs5+ exposed group.Conclusions The expression of MRP2 is increased with increasing dose of arsenic exposure,thus resulting in compensatory changes on MRP2 expression in the liver cell membrane.MRP2 efflux may play an important role in the metabolic pathways of iAs3+.The level or load of arsenic methylation in liver is closely related with MRP2 expression.
ABSTRACT
Objective To observe the infection prevention, wound healing effect and safety of nanometer silver in treatment of Ⅱ degree burn wound. Methods The patients with 6%-10% TBSA Ⅱ degree burn wound ( deep or superficial) were randomly divided into test group ( treated with nanome-ter silver, n =35) and control group (treated with 1% sulfadiazine silver, n =35). Each group was reg-ulated to change dressing and medication one time a day for seven days on 5% superficial Ⅱ degree burn wound. Then, 1% iodophors and gauze were used for change dressing. Before and after change dressing, bacterial culture was done in two groups to observe the time for wound healing. The blood collected before change dressing and at days 1,7 and 14 after change dressing and urine within 24 hours were employed for detecting serum silver level and mean silver level in urine by using inductively coupled plasma mass-spec-trum ( thermoelectricity of American Ⅹ Series Ⅱ ). In the meantime, the liver and renal function was e-valuated at days 7 and 14. Results Positive rate of bacterial culture in test group and control group was 3% and 3.1% respectively after treatment, which showed a decrease compared with the levels before treatment (12. 1% and 15.6% respectively), with no statistical difference. The wound healing time of test group was (9. 18 ± 1.9) days, which was shorter than ( 12.9 ± 1.3 ) days in control group, with sta-tistical difference (P<0.01). Before treatment, the silver level of blood was ( 1.55 ± 1.26) μL and ( 1.54 ± 1.28 ) μg/L respectively in test group and control group, and silver level of urine within 24 hours was ( 1.67 ± 1.05 ) μg and ( 1.87 ± 1.37) μg respectively test group and control group, with no statistical difference (P > 0. 05 ). Silver medication could elevate the serum silver level ( P < 0.01 ), with lower level in test group than control group (P <0. 01 ). Average silver level of urine within 24 hours showed similar change with that in the serum. The patients showed normal renal function, with no abnormal change of ALT. Conclusions For Ⅱ degree burn wound, nanometer silver can more significantly short-en wound healing time compared with sulfadiazine silver. Moreover, nanometer silver has higher degree of safety on silve metabolism and is an ideal medcation for burn wound.