| Objeetive:To explore the protective effects and the beneficial mechanism of induction after rhGH preconditioning,acute ischemic renal injury model of the rats was established(ectomize right kidney,45 min of left renal ischemia and reperfusion for 24 h).and we examined the renal function,the level of IL-6 in serum,histology and renal tubular apoptosis.Methods:Sprague-Dawley rats(n=45) weighting 170-220g(Experiment Animal Center of Kunming Medical College)were used.The rats were divided randomly into 3 groups:sham-operated group(n=15),isehemia-reperfusion group(n=15),rhGH administration group(n=15),sham-operated group and isehemia-reperfusion group had been given N.S 1ml by subcutaneous injection for three days,seven days,ten days beofre renal isehemia,at the same time rhGH administration group had been given rhGh 0.5u/kg.d.The last injection before the operation.A midline incision was made,right nephrectomy was perfomed,the left renal pedicles was occluded with nontraumatic clamp for 45 minutes.Sham-operated group was not occluded.Then Suturing the incision.After 24 hours of reperfusion,the 4ml blood samples were collected from the Inferior vena cava,the left kindey of the rats reperfusion for 24h was cut out for the examination of the histology and renal tubular apoptosis.Serum BUN and creatinine values 24h of reperfusion was measured.the level of IL-6 in serum was measured by enzyme linked immunosorbent assay(ELISA) method.All the left kidney samples were fixed by formalin and Paraffin-embedded, and cut into 4μm sections which were studied by HE stain.With the optical microscope to observe the histological changes and determine the Pathological Scale of renal tubule injury(the mean histologic scores by standards of Paller).By TUNEL to define the levels of apoptotic index(AI) in renal epithelial cells. Data were analyzed with analysis of variance in computerized Spss 12 software. For each of these analyses,two-tailed probability values of P＜0.05 are desinged as significant.Results:1 Serum BUN and creatinine values after 24 hours of reperfusion.As can be seen from the experiment,Serum BUN and Cr values in the sham-operated group in the first 3 days,7 days,the first 10 days were all lower than the IR group at the same time(P＜0.05),that ischemia-reperfusion damage modeling is success.In the first 3 days,Serum BUN and creatinine values in the IR group and rhGH group were,the change is not remarkable,There were no significant differences(P＞0.05).But serum BUN and Cr values in the first 7 days,the first 10 days in the rhGH group were remarkbable lower(P＜0.05) than that of group IR respectively.Serum BUN and creatinine values in the same group(the rhGH group) at the different time points:Serum BUN and Cr values in the first 7 days,the first 10 days in the rhGH group were remarkbable lower(P＜0.05) than the value in the first 3 days.There were no significant differences(P＞0.05) between the Serum BUN and Cr values in the first 7 days,the first 10 days.2 Chnages of IL-6:As can be seen from the experiment,Serum IL-6 values in the sham-operated group in the first 3 days,7 days,the first 10 days were all lower than the IR group at the same time(P＜0.05),that ischemia-reperfusion damage modeling is success.In the first 3 days,the change of serum IL-6 values in the IR group and rhGH group is not remarkable,There were no significant differences(P＞0.05).But serum IL-6 values in the first 7 days,the first 10 days in the rhGH group were remarkbable lower(P＜0.05) than that of group IR respectively.Serum IL-6 values in the same group(the rhGH group) at the different time points:Serum IL-6 values in the first 7 days,the first 10 days in the rhGH group were remarkbable lower(P＜0.05) than the value in the first 3 days.There were no significant differences(P＞0.05) between the Serum IL-6 values in the first 7 days,the first 10 days. 3,Histology studies3.1,The changes of the mean histologic scores by standards of PallerAll kidney samples were examined by HE stain under light microscope.The mean histologic scores by standards of Paller in the sham-operated group in the first 3 days,7 days,the first 10 days were all lower than the IR group at the same time(P＜0.05),that ischemia-reperfusion damage modeling is success.In the first 3 days,the change of the mean histologic scores by standards of Paller in the IR group and rhGH group is not remarkable,There were no significant differences(P＞0.05).But the mean histologic scores by standards of Paller in the first 7 days,the first 10 days in the rhGH group were remarkbable lower(P＜0.05) than that of group IR respectively.The mean histologic scores by standards of Paller in the same group(the rhGH group) at the different time points:the mean histologic scores by standards of Paller in the first 7 days,the first 10 days in the rhGH group were remarkbable lower (P＜0.05) than the value in the first 3 days.There were no significant differences(P＞0.05) between the mean histologic scores by standards of Paller in the first 7 days,the first 10 days.3.2,The changes of the levels of apoptotic index(AI) in renal epithelial cellsThe AI in the sham-operated group in the first 3 days,7 days,the first 10 days were all lower than the IR group at the same time(P＜0.05),that ischemia-reperfusion damage modeling is success.In the first 3 days,the change of the AI in the IR group and rhGH group is not remarkable,There were no significant differences(P＞0.05).But the AI in the first 7 days,the first 10 days in the rhGH group were remarkbable lower(P＜0.05) than that of group IR respectively.The AI in the same group(the rhGH group) at the different time points:the AI in the first 7 days,the first 10 days in the rhGH group were remarkbable lower(P＜0.05) than the value in the first 3 days.There were no significant differences(P＞0.05) between AI in the first 7 days,the first 10 days.Conclusion:1,Pretreatment prior with rhGh 0.5u/kg/d(subcutaneous injection) for seven days befor kidney ischemia.①,It can reduce the degree of the renal function damage and tubular on the pathology;②,It can reduce the level of the serum IL-6;③,It can reduce reduce the apoptosis of tubular epithelial cells.Through this role,rhGH pretreatment on rats renal ischemia-reperfusion injury have protective effects.2,Pretreatment prior with rhGh 0.5u/kg/d(subcutaneous injection) for three days befor kidney ischemia can not protect renal ischemia effectively;Pretreatment prior with rhGh 0.5u/kg/d(subcutaneous injection) for seven days befor kidney ischemia can protect renal ischemia effectively;There were no significant differences between pretreatment prior with rhGh 0.5u/kg/d(subcutaneous injection) for seven days and ten days befor kidney ischemia on protecting renal ischemia.3,There will be a good clinical application prospect in renal ischemia-reperfusion injury protection, due to the small amount of rhGH,no significant side effects. |
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