Effect of bitter gourd saponins on the expression of ET-1 in renal tissues of rats with renal damage induced by salt-sensitive hypertension / 中国基层医药

ABSTRACT

Objective To investigate the effect of bitter gourd saponins on the salt -sensitive hypertension caused kidney damage in rats ,and analyze the mechanism of its therapeutic effect .Methods 50 SD rats were fed for 10 days with normal diet ,and then based on random number method ,the rats were randomly divided into 5 groupsthe normal control group,model control group and the low total saponins bitter,medium and high dose treatment group,10 rats in each group.Then,the rats in the normal control group and the model control group were given 1mL· kg-1 · d-1 normal saline,and the rats in bitter gourd saponins groups were given high salt diet 8 weeks to establish the model .After 4 weeks,the total saponins of bitter gourd treatment groups were given 10,20 and 40mg· kg-1· d-1.8 weeks later, the rats were sacrificed and the renal pathology was detected by HE staining .The changes of blood pressure , heart rate,urinary function and blood renal function were also analyzed .At last,Western blot and semi -quantitative PCR were used to detect the endothelin -1 (ET-1) in renal tissue.Results For the systolic blood pressure,in whole of treatment,the normal control group maintained at about 120 mmHg, while the model control group maintained at 170mmHg,which of the bitter gourd saponins three doses groups compared to the model control group was significantly lower (t=1.765,1.982,2.126,all P<0.05),further improved.And the heart rate had no statistically significant difference among the groups(all P>0.05).Compared with the normal control group,the blood urea nitrogen (BUN), creatinine (Cr),uric acid (UA),urine volume,urinary protein and N -acetyl beta -D-Glucosaminidase (NAG) levels in the model control group were significantly increased (t=28.703,33.932,29.298,4.695,10.989,10.871, all P<0.05),which in the bitter gourd saponins treatment groups were significantly decreased (all P<0.05).HE staining showed that the rats in the normal group were normal ,and the model control group had obvious glomerular sclerosis and renal interstitial fibrosis , after bitter gourd saponins treatment , the condition was significantly improved .Immu-nohistochemistry,Western blot and semi-quantitative PCR showed that normal control group had almost a little expression of ET-1,and compared with the normal control group ,which of the model control group was significantly increased ( t=14.650,11.387,all P<0.05),and the ET-1 expression in the bitter gourd saponins treatment groups significantly decreased.Conclusion The bitter gourd saponins can significantly improve the symptoms of hypertension and renal damage induced by high salt diet in rats ,which may be related with regulation of ET -1 expression in renal tissue .