Studies on the Effectiveness of Sairei-to on Puromycin Aminonucleoside Nephrosis in Rats

In order to assess the effectiveness of sairei-to on nephrosis and to elucidate its mechanism of action, we made a puromycin aminonucleoside (PAN) rat model by a single intra-peritoneal injection of PAN at a dose of 100mg/kg body weight (B.W.) and compared it to the normal controls. Sairei-to was administered in various doses (100,200,500mg/kg B.W.) orally for 8 days after the initial injection of PAN. Proteinuria and serum triglyceride levels were significantly reduced in the sairei-to-treated groups which had been pretreated with PAN. Light and electron microscopically sairei-to-treated groups showed a morphological improvement in the kidney over the PAN group. We found 500mg/kg B.W. of sairei-to to be the most effective dose. The superoxide dismutase (SOD)-like activity was significantly elevated in the serum but not changed in the urine of sairei-to-treated groups pretreated with PAN. The normal control fed with 500mg/kg B.W. of sairei-to showed a significant increase in serum SOD-like activity. The urinary prostanoid levels in the PAN group were lower than those in the normal and sairei-to-treated groups. These results support our hypothesis that sairei-to has effects on the elevation of SOD-like activity and on the synthesis of prostanoid in PAN-induced nephrosis, and that these effects are responsible for the mechanism of action of sairei-to.