Protective effect of gypenosides on free radical damage of isolated guinea pig papillary muscles
IU Li-Bo,HU Bi,LIAO Duan-Fang1 (Dept of Physiology; 1Dept of Pharmacology, Hengyang Medical College,Hunan 421001)
This paper studied the protective effect of gypenosides (GPS) on oxidative damage of myocardium of guinea pig, Using xan-thine-xanthine oxidase (X-XOD) producing free radicals. In the isolated guinea pig papillary muscles, X- XOD produced the quick positive inotropism at first and then the continuous negative one, shortened the functional refractory period (FRP) and elevated the excitability and increased the automaticity induced by adrenaline, inhibited the activity of superoxide dismutase (SOD) and increased the content of malondi- aldehyde (MDA). GPS inhibited the negative inotropism of papillary muscles produced by X-XOD,resisted the changes of FRP, automaticity and excitability induced by X- XOD. Meanwhile, GPS antagonized the effect of X-XOD which decreased activity of SOD and increased the content of MDA. These studies indicate that GPS can protect the myocardium from oxidative damage.