| Objective: To observe the effect of Salidroside against exhaustive rat heart by detecting mRNA and protein level of Nrf2,GXP and CAT in the myocardial cell treated with Salidroside after exhaustive swimming.To explore the role of Salidroside against exhaustive rat heart injure through oxidative strees mechanism and Keap1-Nrf2-ARE pathway.Methods: Healthy SD rat were randomly divided into four groups(n=6): control group(CON),exhaustive rat group(EE),high-dosage salidroside group(SLE),low-dosage salidroside group(SHE).All the rats in control group were not to do any exercise.The rats in exhaustive rat group were given 0.9% NaCl by intraperitoneal injection two weeks.The rat in SLE group and SHE group were given salidroside(30mg·kg-1·d or 15mg·kg-1·d)by intraperitoneal injection two weeks.The rats did moderate exercise by swimming for three times(20minutes once time).After two weeks,the rats in SLE and SHE group did repeated exhaustive exercise by swimming.All the rats must fast before taking exercise for 12 hours.Keep the water temperature in 33 ?,and the temperature of the water float up and down not more than 1 ?.The rat' tails in all exhaustive rat groups were given 3% weight of tin wire,exhaustive exercise by swimming.According to the standard of Thomas,after 10 s rats are still unable to return to the surface of the water,fished out and then placed in the plane can't complete to regain the righting reflex,all those features listed above showed we built up exhaustion exercise myocardial damage experimental animal model successfully.ROS,GPX,CAT in blood serum were determined by ELISA.The mRNA and protein level of Nrf2 and Keap1 in the myocardial cell treated with Salidroside after exhaustive rat heart were detected by RT-PCR and Western blotting.Dates are expressed as the mean±SE.Statistica software(SPSS16.0)performed ANOVA to statistical analysis.P <0.05 was considered statistically significant.Result: 1 Compared with the levels of ROS in the Con group(3.69±0.42 ng/mg),EE,SLE and SHE group(7.66±0.81ng/mg,6.25±0.36ng/mg,4.91±0.74 ng/mg)were obviously increased.SHE,SLE was significantly decreased(P<0.01),and the degree of reduction was concentration dependent(P<0.01)compared with exhaustive group.2 The content of GPX in EE,SLE and SHE group in myocardium(2.00±0.47 U/mg,2.23±0.21 U/mg,2.60±0.47 U/mg)was markly decreased compared with the values of Con group(3.58±0.67 U/mg).Compared with Con group(0.61±0.06 ng/mg),the contents of CAT in EE and SLE group(0.46±0.03ng/mg,0.53±0.03 ng/mg)were decreased(P<0.01),while the content of CAT in SLE and SHE group was increased compared with the level of EE group.3 Compared with Con and EE groups,the expression of Nrf2,Keap1 in myocardial cells of SHE,SLE group was significantly increased(P<0.01).Salidroside induced Nrf2 nuclear translocation to the nucleus in a concentration dependent manner.Conclusion:1 After exhausted exercise the oxidative stress levels of the body were higher,which was may be one of the important mechanisms of leading to myocardial cell damage.2 Salidroside can activate the Nrf2 signaling pathway and promote its nuclear transfer,increasing the expression of its downstream antioxidant enzyme.As a result,it can reduce level of the oxidative stress and reduce the damage oxygen free radical given to the heart. |
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