| Objective: Overtraining can induce acute kidney injury.The pathogenesis of acute kidney injury induced by overtraining has not been definited.The recent research shows that apoptosis may play an important role in the pathogenesis of kidney injury induced by overtraining,but the precise molecular mechanism of apoptosis in kidney is not elucidated,there are not effective drug therapy to prevent and cure it at clinic by far.In the present study,the animal model of overtraining-induced acute kidney injury was developed by swimming to exhaust in rats.Through observing histopathological changes of kidney and examining the activity of SOD,the content of MDA in renal tissues as well as observing the expressions of Caspase-3 and the cleavage and inactivating of PARP-1,The authors tried to verify the role of activating of PARP-1 by oxidant-induced DNA damage and cleaving by Caspase-3 in overtraining-induced acute kidney injury, on the other hand, also observed the protective effects of anisodamine on acute kidney injury, in order to understand the pathogenesis of overtraing-induced acute kidney injury deeply and offer the theory support and test proof for prevation and cure. Methods: (1) 36 male Wistar rats weighing 200-220g were randomly divided to the normal control group(CN group),exhausting swim group(ES group) including immediate group after exhausted swim(ESI group),6h group after exhausted swim(ES6h group),24h group after exhausted swim(ES24h group),Anisodamine group(AD group) including 6h group after exhausted swim treated with anisodamine (AD6h group) and 24h group after exhausted swim treated with anisodamine (AD24h group).(2)Rats swam to exhaust so as to developing the model of overtraining-induced acute kidney injury;(3)Exhausted rats were anaesthetized with inhaling ether.The left renal tissues of rats were collected in order to observe histologic and immunohistothemical staining changes.The right tissues of rats were saved in refrigerator of -80℃in order to detect SOD,MDA and implement western blot analysis.(4)The activity of SOD and the content of MDA were detected.(5)The renal histopathology change were observed with light microscope in HE staining.(6)The expression of caspase-3 and PARP-1 were detected by immunohistothemical staining.(7)The results of immuno- histothemical staining were analyzed with the pathological image analysis system.(8)The cleavage of PARP-1 were detected by western blot analysis.(9)All data were statisticed by spss 11.0 for windows,P<0.05 had statistical significance.Result: (1)Light microscopy showed that the dilation of tubules and glomeruli in renal tissues of ESI group and ES6h group, in addition, the phenomena of gore could be observed in the renal tubules of corticomedullary segments. Brush border of the renal tubules loss partly and vacuolization of tubules were observed in ES24h group.Compared with ES groups ,those changes in Anisodamine group were lighter. (2)The activity of SOD in exhausted swim group were lower than normal control group(P<0.05) and fall to bottom at 6h after exhausted swim, there were significant improvement in Anisodemine group compared with exhausted swim group(P<0.05).The levels of MDA in exhausted swim group were higher than normal control group(P<0.05),there were significant reduction in Anisodemine group compared with exhausted swim group. (3) Immunohisto- chemistry staining showed that the expression of Caspase-3 in exhausted swim group were higher than control group(P<0.05),the expression increased in ES group following the time continued,especially in ES24h group. (4)Immunohisto- chemistry staining showed that there was only little expression of PARP-1 in the tubules of kidneys in control group,the expression of it was higher in ESI group than CN group(P<0.05),but no obvious cleaving of PARP-1 was detected,following the time continued after exhausted swim,cleaving of PARP-1 was more and more increased significantly,especially in ES24h. In Anisodemine group,the expression of Caspase-3 and the cleaving of PARP-1 were reduced.Conclution:(1)The activity of SOD and the contents of MDA in renal tissues of exhausted swim group were higher than Control group ,oxidative stress contribute to the acute kidney injury induced by overtraining and play an important role.(2)The expression of caspase-3 in the ES group was increased following the time continued after exhausted swim ,the expression of PARP-1 was also increased in ESI group,but no obvious cleavage of PARP-1 were detected,the cleavage of PARP-1 was more and more increased significantly following the time continued after exhausted swim .the results show that caspase-3 and cleavage of PARP-1 by caspase-3 play a crucial role in the cell apoptosis of kidney induced by overtraining.(3)Anisodamine could reduce the content of MDA and increase the activity of SOD,down-regulate the express and activity of caspase-3 and cleavage of PARP-1,which may be one of the protective mechanism of Anisodamine in the cell apoptosis of kidney induced by overtraining.
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