RESUMO
Objective To observe the expression of aquaporin-7 (AQP-7)during the development of renal tubules of mice,and investigate the relationships between AQP-7 and renal tubule development.Methods Kidneys were selected from mice at embryonic days(E)12,14,17,and 18 and postnatal days(P)1,3,7,14,24,40 and 70.The expression of AQP-7 was observed by immunohistochemical(IHC)method in renal tubules.The surface area density values of AQP-7 positive expression were measured by stereological method while the content variation of AQP-7 in the renal tissue of mice was examined by Western blot.Results IHC analysis showed that AQP-7 was expressed in developing renal tubules at the proximal tubule at E14 day,localized along the brush border of the proximal straight tubules (S3 segment)where the cortex and outer medullalie after P14 d,but AQP-7 was not observed in the nephrogenic zone or inner medulla.The results of stereology discovered that the surface area density values of AQR-7 had increased gradually in the apical of renal tubule and reached the maximum at P24 d and then remained stable with the growth of mice.Western blot indicated that AQP-7 expression in kidneys had reached the peak at P24 d and remained stable.Conclusion The expressions of AQP-7 in the developing renal tubules of mice show a chronological and spatial sequence,which plays an important role in water and glycerol balance of mouse kidneys at the late stage of development.