AIM: To observe the dysfunciton of myocardial nuclear calcium transport in rat myocardial injury and the effects of liqustraxin on it. METHODS: The model of myocardial damage was induced by subcutaneous injection of isoproterenol (ISO,5 mg?kg -1?d -1). Myocardial nuclei were purified with sucrose density centrifugation and identified zymologically. The activity of Ca 2+-ATPase was measured zymologically and calcium uptake was assayed with 45Ca 2+ isotope. RESULTS: Compared with the control,the Ca 2+-ATPase activity of myocardial nuclear membrane in ischemia group(exprimental) was decreased by 18.1% (P