Author + information
- Peng Xu,
- Weiwei Sun,
- Haiyan Liu,
- Zheng Ping and
- Xuebin Cao
To clarify whether salidroside (Sal) can improve the cardiac function impaired by exhaustive exercise in rats, which was related to reduce oxidative stress of myocardial cells through regulating the expression of nuclear factor erythroid-2-related factor2 (Nrf2).
Male SD rats randomly divided into 4 groups (n=6): control group (Con), exhaustive exercise group (EE), low-dose and high-dose Sal pretreatment exhaustived swimming group (SEL, SEH). Groups were given Sal solution (15 or 30mg/kg/d) or the amount of normal saline through intraperitoneal injection 14 days. The EE, SEL and SEH groups' rats were forced to swim until they were exhausted.Cardiac function of rats was recorded by pressure-volume catheter. The changes of reactive oxygen species (ROS), glutathione peroxidase (GPX), and catalase (CAT) in cadiocyte were observed by ELISA, respectively. Western blot method was used to detect the expression of Nrf2 in myocardium and the nuclear translocation of Nrf2.
①left ventricular end systolic pressure (Pes, 80.33±11.82mmHg), developed pressure (Pdev, 96.88±8.08mmHg), arterial elasticity (Ea, 0.54±0.05 mmHg/μL), the peak rate of left ventricular pressure rise/decline (dP/dtmax, 6294.33±1224.59 mmHg/s, -dP/dtmin-5274.67±797.70 mmHg/s), end diastolic pressure volume relationship curve slope (ESPVR, 0.90±0.17) in the EE group were decreased, which had significant difference compared with the Con group, while left ventricular end diastolic volume (Ved, 242.42±9.18μL), end diastolic pressure (Ped, 7.03±1.60mmHg), end systolic volume (Ves, 98.51±9.06μL), stroke volume (SV, 149.80±10.17μL), and Tau value (15.84±3.47ms) increased. Besides, SV, Ved, Ped, ejection fraction (EF), and Tau in the SEL, SEH group were increased, while Pdev, Ea, ESPVR were decreased, which had significant difference compared with the Con group. SV, Pes, EF, dP/dtmax, -dP/dtmin and ESPVR of SEL and SEH were increased significantly compared with EE group. ②Compared with the level of ROS in the Con group (3.69±0.42 ng/mg), EE, SLE and SHE group was obviously increased. The level of ROS in SHE and SLE group was decreased (P<0.01), and the degree of reduction was concentration dependent (P<0.01) compared with EE group. ③The content of GPX in EE, SLE and SHE group in myocardium 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 was decreased (P<0.01), while the content of CAT in SLE and SHE group was increased compared with EE group. ④Compared with Con and EE groups, the expression of Nrf2 in myocardial cells of SHE, SLE group was increased (P<0.05), and Sal increased the expression of Nrf2 and induced Nrf2 nuclear translocation to the nucleus in a concentration dependent manner.
Sal can improve the cardiac function impaired by exhaustive exercise, which was related to reducing oxidative stress of cadiocyte through increasing the expression and promoting nuclear translocation of Nrf2 to modulate GPX and CAT.