Abstract: AIM: To observe the effectsofligustrazine on dysfunction of myocardial nuclear calcium transport in ischemic myocardial cellsof rats.METHODS: The isch-emic models of myocardial cells were induced by subcuta-neous injection of isoproterenol (ISP,5 mg·kg^-1·d^-1).Myocardial nuclei werePurified with ultracentrifugation and identified by enzymological assay.The activity of Ca²⁺-ATPase was measured by the same way and calcium uptake was assayed with⁴⁵Ca²⁺isotope.RESULTS: The Ca²⁺-ATPase activity of myocardial nuclear membrane in ischemia grouPwas decreased by 21.4% (P<0.05)in comparison with that in control group.The nuclear⁴⁵Ca²⁺uptake significantly decreased,and V_maxvalue also de-creased by 48.5%.V_maxand K_mof ATPase decreased by about 34.1% (P<0.05)and 42.2%(P<0.01)re-spectively.Ca²⁺-ATPase activity and 45 Ca²⁺uptake inthe myocardial nuclei of theligustrazin grouPshowed no significant change.CONCLUSION: Ligustrazin has no-tablyProtective effects on dysfunction of nuclear calcium transport in myocardial cells of rats.

Key words: pharmacology, ligustrazin, Ca²⁺trans-port, nucleus, Ca²⁺-ATPase, myocardium