ABSTRACT
<p><b>OBJECTIVE</b>To investigate the myocardial damage and changes of myocardial mitochondrial Mn-superoxide dismutase (Mn-SOD) activity in craniocerebral injured rats and the effect of Ginkgo biloba extract (GBE) on them.</p><p><b>METHODS</b>Craniocerebral injured rats model was established by fluid-percussion and treated with GBE. The dynamical changes of electrocardiograph (ECG) in 24 h were monitored, the serum level of MB isoenzyme of creatine kinase (CK-MB) and the change of myocardial mitochondrial Mn-SOD activity as well as the pathologic changes of myocardium (HE staining) were observed.</p><p><b>RESULTS</b>The occurrence of ECG abnormality obviously increased in the injured rats, accompanied with increased serum CK-MB (P<0.05) and decreased myocardial Mn-SOD levels (P<0.05), and the Mn-SOD activity was negatively correlated with the level of CK-MB (r=-0.997, P<0.05). Pretreatment of GBE resulted in the decrease of ECG abnormality occurrence (P<0.01), serum CK-MB level (P<0.05), and degree of myocardial damage, as well as the increase of Mn-SOD activity in post-craniocerebral injured rats.</p><p><b>CONCLUSIONS</b>Craniocerebral injury can result in distinct myocardial damage, which is possibly correlated with the lowering of anti-oxidation stress level of myocardial cellular mitochondria. GBE possesses the protective effect on myocardial damage after craniocerebral injury.</p>