Renoprotective Effect Of Erigeron Breviscapus On Tubulointerstitium In Rats With Adriamycin-induced Nephropathy

Objectives:To investigate the protein expression of endothelin-1(ET-1) in renal tissue as well as the levels of serum and urine endothelin in adriamycin-induced nephropathy and the influence of erigeron breviscapus; To explore the possible mechanism of erigeron breviscapus'renoprotective effect.Methods:28 SD male rats were divided into three groups (nephropathy, treated and control groups) at random. Adriamycin was intravenous administered twice (5mg/kg and 3 mg/kg) to prepare adriamycin nephropathy model. The rats of treated group received erigeron breviscapus (15mg/kg.d) daily for 4 weeks. Twenty-four hours urinary protein, as well as serum creatinine and albumin, were measured with automatic biochemistry analyzer. Serum and urinary endothelin levels were measured by radioimmunoassay after sample extraction and purification. Renal histology change was assessed on HE, PAS and Masson staind sections.Specific expression of ET-1 in the renal tissue was examined using immunohistochemistry.Results:1) Urinary protein excretion, serum creatinine, renal histology change were significantly inceased, whereas serum albumin was reduced in nephropathy group compared with control group(P<0.01), and all these abnormalities were ameliorated by erigeron breviscapus.2) Urinary endothelin excretion was significantly increased in nephropathygroup higher than that in control group(P<0.01), and was significantly decreased by erigeron breviscapus(P<0.01). The serum endothelin levels were not different among the groups and remained stable throughout the study. 3) The immunohistochemical analyses shows that ET-1 mainly located in tubular epithelial cells. Over-expression of ET-1 was observed in nephropathy group compared with control group(P<0.01), and was inhibited significantly by erigeron breviscapus(P<0.01). 4) The expression of ET-1 in renal tissue was positive correlated with urinary endothelin excretion, urinary protein excretion, and serum creatinine. In addition, increased urinary endothelin excretion correlated with the rise in serum creatinine and proteinuria.Conclusions: 1) The increased protein expression of ET-1 and urinary endothelin excretion were observed in adriamycin-induced nephropathy, which was related to the progression of nephropathy. 2) Erigeron breviscapus have an effect of reducing proteinuria, preserving renal function, alleviating renal histology change on adriamycin nephropathy. 3) Inhibiting the synthesization and exretion of endothelin-1 in kidney may be one of the mechanisms of erigeron breviscapus'renoprotective effect.