[Grain-Moxibustion may Protect Myocardium by Reducing Oxidative Stress in Doxorubicin-induced Cardiomyopathy Rats].

OBJECTIVE: To observe the effectiveness of grain-moxibustion in resisting oxidative stress in doxorubicin (DOX)-induced cardiomyopathy rats.

METHODS: Sixty Sprague-Dawley (SD) rats were randomly divided into blank control group (blank group), cardiomyopathy model (model) group and grain-moxibustion (moxibustion) group, with 20 rats in each one. The cardiomyopathy model was established by intraperitoneal injection of DOX (0.5 mg/100 g), once a week for 4 weeks. Grain-moxibustion was applied to "Guanyuan" (CV 4) and "Juque" (CV 14) for 5 cones, once daily for 4 weeks except the Sundays. The rats' heart rate (HR), left ventricular systolic pressure (LVSP), left ventricular diastolic pressure (LVDP), left ventricular pressure maximum rising rate (+dp/dtmax ), left ventricular pressure maximum decline rate (-dp/dtmax ), left ventricular pressure change time (t-dp/dtmax ) were detected to evaluate the cardiac function by using a physiological signal acquisition-analysis system. The pathological changes of the myocardium were observed by optical microscopy after H.E. staining. The activity of serum lactate dehydrogenase(LDH), creatine kinase(CK) and myocardial superoxide dismutase (SOD), and myocardial malondialdehyde (MDA) and serum cardiac troponin Ⅰ(cTnⅠ) contents were assayed by enzyme-linked immuno sorbent assay kit (ELISA).

RESULTS: Following modeling, the HR, LVSP, +dp/dtmax , -dp/dtmax , and myocardial SOD activity were significantly down-regulated ( P <0.05, P <0.01), while the LVDP, t-dp/dtmax , serum LDH and CK activity and cTnⅠ content, as well as myocardial MDA content were considerably increased in comparison with the blank group ( P <0.05, P <0.01). After moxibustion intervention, the decreased HR, LVSP, +dp/dtmax , -dp/dtmax , and myocardial SOD activity levels and the increased LVDP, t-dp/dtmax , serum LDH and CK activity and cTnⅠ content, as well as myocardial MDA content were remarkably suppressed in comparison with the model group ( P <0.05, P <0.01).

CONCLUSIONS: Grain-moxibustion can significantly improve the left ventricular function, increase heart rate in cardiomyopathy rats, which may be associated with its effects in reducing myocardial oxidative stress damage by down-regulating the content of MDA and up-regulating SOD activity in the heart.