摘要Background Intermediate filament(IF)proteins have been thought to play a role in nuclear centration,organelle movement and maintenance of cell shape.dl-praeruptorin A(Pd-la),a novel Ca2+-influx blocker and K+-channel opener isolated from Chinese traditional herbal medicine Qian-Hu,has been demonstrated to inhibit expression of apoptosis related proteins and reduce the level of proinflammatory factors in ischemia/reperfusion myocardiocytes.Morphologically,whether Pd-la effects myocardiocyte IFs remains unclear.The purpose of this study was,for the first time,to evaluate the in vivo effects of Pd-la on IF desmin and vimentin content in order to further explore its cardioprotection against ischemia and elucidate its mechanism of action.Methods Rats underwent a 30 minutes coronary occlusion followed by 120 minutes reperfusion.Assessment of desmin and vimentin content of myocardiocytes was performed by immunohistochemistry,Western blot,Hematoxylin-Eosin staining and densitometry.Results Pretreatment with i.v. infusion of Pd-la prior to ischemia significantly increased desmin and vimentin content and alleviated defects caused by the ischemia/reperfusion insult,e.g.with Pd-la at a dose of 0.5 or 1.0 mg/kg,integrated density values of desmin were increased from 61 478±10 074 to 177 408±10 395 and 195 784±20 057,and vimentin from 59 189±19 853 to 164 781±19 543 and 185 696±20 957(P<0.01,vs placebo),respectively.The recovery of desmin seemed to be stronger and appeared earlier than that of vimentin.Conclusion Pd-la protectively increased IF desmin and vimentin content in ischemia/reperfusion myocardiocytes,which might be partially responsible for its cardioprotection against ischemia.