Glomerular expression of apelin and its association with proteinuria.

Abstract

OBJECTIVE: To investigate the distribution and expression of apelin in kidney of adriamycin (ADR)-induced nephrotic rats, and to explore the possible association of apelin expression with the development of proteinuria. METHODS: Immunohistochemical staining for apelin was used to examine the expression and distribution of apelin in kidney of adriamycin (ADR)-induced nephrotic rats at 7, 14, 21 and 28 d after adriamycin injection. The level of serum apelin at 7, 14, 21 and 28 d after ADR injection was also determined with ELISA methods. Moreover the correlation of urine protein and glomerular expression of apelin was analyzed. RESULTS: The apelin protein was immunohistochemically detected along glomerular basement membrane (GBM) in the kidney of rats and significantly increased compared with normal control rats after ADR injection. The levels of 24 h proteinuria and serum apelin were also elevated after ADR injection. Moreover the production of proteinuria was correlated positively with the expression of apelin in kidney tissue (rs&#x2009;=&#x2009;0.9427, P&#x2009;<&#x2009;0.01). CONCLUSIONS: The glomerular expression of apelin increased significantly in ADR rats, which is correlated with urine protein.