OBJECTIVEThe pathogenesis of minimal change nephrotic syndrome (MCNS) remains unclear. This study aimed to investigate the expression of interleukin-6 (IL-6) in rats with doxorubicin-induced nephropathy and its possible roles in the pathogenesis of MCNS.

METHODSEighty-three male Wistar rats were randomly assigned into a control group (n=32) and a nephropathy group (n=51). Nephropathy was induced by a single tail vein injection of doxorubicin (5 mg/kg). The control group was injected with normal saline. Twenty-four-hour urinary protein excretion was measured 7, 14, 28 and 42 days after doxorubicin injection. IL-6 expression in urine and renal tissues was determined using ELISA 7, 14, 28 and 42 days after doxorubicin injection.

RESULTSThe urinary protein excretion increased significantly in the nephropathy group 7, 14, 28 and 42 days after doxorubicin injection compared with that in the control group (P<0.01). IL-6 expression in urine and renal tissues increased significantly 7, 14, 28 and 42 days after doxorubicin injection compared with that in the control group (P<0.01). IL-6 expression in urine and renal tissues was positively correlated with 24-hour urinary protein excretion in the nephropathy group (r=0.794, P<0.01; r= 0.870, P<0.01). IL-6 expression in urine was positively correlated with that in renal tissues (r=0.739, P<0.01).

CONCLUSIONSIL-6 expression in the urine and renal tissues is increased in MCNS rats. IL-6 might play an important role in the pathogenesis of MCNS.