间接酶联免疫吸附法定量检测大鼠尿液水通道蛋白-2浓度

Quantitative measurement of urinary excretion of aquaporin-2 water channel protein in rat by indirect ELISA

目的通过间接酶联免疫吸附测定(ELISA)法,检测正常大鼠不同水代谢状态下尿液水通道蛋白-2(AQP2)。方法收集大鼠正常,禁水24 h以及水负荷状态(80 ml/kg)下的尿液,用间接ELISA法检测尿液中AQP2。结果本方法批内差异系数6.5%,批间差异系数7%,灵敏度为112.5 pmol/L;禁水24 h后大鼠尿液AQP2/肌酐显著增加(P<0.01),给予水负荷后尿液AQP2/肌酐显著降低(P<0.01);且尿渗量与尿液AQP2/肌酐呈正相关(r=0.952,P<0.001)。结论间接ELISA法可以较好地检测大鼠尿液中AQP2。

Objective To develop an efficient and stable enzyme-linked immunosorbent assay （ELISA） for measuring urinary aquaporin-2（AQP2） water channel protein. Methods Twenty-four hour urine of SpragueDawley rats was collected in various conditions of water metabolism and measured by indirect ELISA. Results The ELISA method could detect as low as 112.5 pmol/L AQP2 with intra-and inter-assay coefficients of variation （CVs） being 6.5 % and 7 % respectively. After dehydration for 24 hours, urinary AQP2/ereatinine （Cr） increased （ P 〈 0.01）. Subsequently, the rats were given oral water loading（80 ml/kg） and urinary AQP2/Cr significantly decreased （ P 〈 0.01）. Also, urinary AQP2/Cr was positively correlated with urine osmolarity. Conclusion Indirect ELISA suitable for urinary AQP2 detection was established.