Effect of erythropoietin on the expression of aquaporin 2-3 after the release of unilateral ureter obstruction in young rats / 中华实用儿科临床杂志

ABSTRACT

Objective To investigate the effect of erythropoietin (EPO) on the expression of aquaporin 2-3 after the release of unilateral ureter obstruction in young rats.Methods Twenty-four SD rats were randomly divided into 3 groups(CUUO-R group,CUUO-R + EPO group and sham group,with 8 rats in each group).The CUUO-R model was built through unilateral ureteral ligation,after 48 h the obstruction was released.EPO was given to the CUUO-R + EPO group at the time point of removing obstruction,and then repeated every other day for 1 week,and the same volume of saline was simultaneously given to the CUUO-R rats.The rats in sham group experienced the laparotomy and free dissection of left ureter but not ligation.The kidneys were harvested 7 d after the release of CUUO.The methods of Western blot and immunohistochemistry were used to examine the effects of erythropoietin on the expression of AQP2 and AQP3.Results The osmotic pressure of CUUO-R + EPO group was higher than those of CUUO-R group,but lower than that of sham group (P =0.007).The concentration of creatinine and urea in the CUUO-R group [(58.001 ± 2.416) μmol/L and (9.025 ± 1.158) mmol/L] were higher than those of CUUO-R + EPO group [(57.072 ± 2.286) μmol/L and (1.479 ± 0.043) mmol/L] and sham group [(54.820 ± 1.536) μmol/L and (6.929-±0.604) mmol/L].The differences of the concentration of creatinine and urea between CUUO-R group and sham group were statistically significant (P ＜ 0.05).There was no significant difference between CUUO-R + EPO group and Sham group(P ＞ 0.05).The immunohistochemistry showed that the expressions of AQP2 and AQP3 in collecting duct in CUUO-R group were significantly weaker than those of in sham group,and the expression of those in CUUO-R + EPO group were slightly weaker than sham group.These results were further confirmed by Western blot,as the relative quantity of AQP2 and AQP3 were also the lowest in CUUO-R group (AQP2 in 3 groups were 0.974 ± 0.109,1.923 ± 0.097 and 2.002 ± 0.044,F =392.4,P =0.000;AQP3 in 3 groups were 0.941 ± 0.048,1.497 ± 0.043 and 1.863 ± 0.043,F =735.8,P =0.000).Conclusions EPO treatment is beneficial for the recovery expression of AQP2 and AQP3 as well as renal function at the early period after the release of ureteral obstruction in young rats.