Objective: To investigate the effects of intravenous injection of defibrinogenase on dissoliving dissolve thrombus and salvaging cerebral infarction in stroke-prone renovascular hypertension rats (RHRSP) with middle cerebral artery occlusion(MCAO).
Methods: The MCAO in RHRSP was induced by administration in photosensitive dye, rose bengal, and irradiation of the main MCA with a focus laser beam. The thrombus in MCA and cerebral infarction were examined microscopically in HE stained sections. Infarction size was determined in triphenyltetrazolium chloride stained sections. Defibrinogenase was injected intravenously at 3, 6, 9, 12 hours and 3, 7 days after MCAO, meanwhile the control group received normal saline. All rats were killed at 72 hours and evaluated by pathological methods after treatment.
Results: In the treatment group, the thrombi were dissolved totally at 3 hours after MCAO, 75% at 6 hours, 13% at 9 hours. Defibrinogenase failed to dissolve thrombus beyond 12 hours after MCAO, just as control group. In comparison with the control group, defibrinogenase significantly reduced infarction size. There was no evidence of hemorrhage.
Conclusions: Defibrinogenase can reduce infarction size and dissolve thrombus in 6 hours after MCAO without the side effect of hemorrhage.