Reduction of intracerebral hemorrhage by rivaroxaban after tPA thrombolysis is associated with downregulation of PAR-1 and PAR-2

Ryuta Morihara, Toru Yamashita, Syoichiro Kono, Jingwei Shang, Yumiko Nakano, Kota Sato, Nozomi Hishikawa, Yasuyuki Ohta, Stefan Heitmeier, Elisabeth Perzborn, Koji Abe

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19 Citations (Scopus)


This study aimed to assess the risk of intracerebral hemorrhage (ICH) after tissue-type plasminogen activator (tPA) treatment in rivaroxaban compared with warfarin-pretreated male Wistar rat brain after ischemia in relation to activation profiles of protease-activated receptor-1, -2, -3, and -4 (PAR-1, -2, -3, and -4). After pretreatment with warfarin (0.2 mg/kg/day), low-dose rivaroxaban (60 mg/kg/day), high-dose rivaroxaban (120 mg/kg/day), or vehicle for 14 days, transient middle cerebral artery occlusion was induced for 90 min, followed by reperfusion with tPA (10 mg/kg/10 ml). Infarct volume, hemorrhagic volume, immunoglobulin G leakage, and blood parameters were examined. Twenty-four hours after reperfusion, immunohistochemistry for PARs was performed in brain sections. ICH volume was increased in the warfarin-pretreated group compared with the rivaroxaban-treated group. PAR-1, -2, -3, and -4 were widely expressed in the normal brain, and their levels were increased in the ischemic brain, especially in the peri-ischemic lesion. Warfarin pretreatment enhanced the expression of PAR-1 and PAR-2 in the peri-ischemic lesion, whereas rivaroxaban pretreatment did not. The present study shows a lower risk of brain hemorrhage in rivaroxaban-pretreated compared with warfarin-pretreated rats following tPA administration to the ischemic brain. It is suggested that the relative downregulation of PAR-1 and PAR-2 by rivaroxaban compared with warfarin pretreatment might be partly involved in the mechanism of reduced hemorrhagic complications in patients receiving rivaroxaban in clinical trials.

Original languageEnglish
Pages (from-to)1818-1828
Number of pages11
JournalJournal of Neuroscience Research
Issue number9
Publication statusPublished - Sept 2017


  • PAR-3
  • PAR-4
  • tissue plasminogen activator
  • warfarin

ASJC Scopus subject areas

  • Cellular and Molecular Neuroscience


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