Effect of Ginkgolides on Myocardial Ischemic Injury Induced by Isoprenaline / 中药新药与临床药理

ABSTRACT

Objective To observe the effects of ginkgolides on hypoxia tolerance in mice and on myocardial ischemia injury in rats.Methods The mice were given isoprenaline 20 mg/kg(ip) and the survival time of the mice model under the hypoxic condition was recorded. Rat myocardial ischemia was induced by subcutaneous injection of over- dosage isoprenaline(8 mg/kg). Before modeling, rats were pretreated with ginkgolides 10, 20, 40 mg/kg, of ginkgo biloba( EGb) Extract 300 mg/kg, Propranolol 5 mg/kg,or vehicle for four days. The histological changes of myocardiim, serum creatine phosphokinase (CPK) level and lactate dehydrogenase (LDH) activity, myocardial lactate dehydrogenase(LDH) and superoxide dismutase (SOD) content were detected.Results Ginkgolides could prolong the survival time in the mice under a hypoxic condition, lessen the isoprenaline- induced rat myocardial ischemia, inhibit the activities of serum CPK and LDH and the increase of MDA content in ischemic myocardial tissue, enhance superoxide dismutase (SOD) activity. Conclusion Ginkgolides enhance to hypoxia the tolerance in mice and prevent rats from myocardial ischemic injury. The protective mechanism may be related to its inhibition of the activity of platelet activating factor and oxygen free radical. 