Effects of Low-Dose Unfractionated Heparin Pretreatment on Early Brain Injury after Subarachnoid Hemorrhage in Mice.

Heparin is a pleiotropic drug that antagonizes many pathophysiological mechanisms. In this study, we evaluated whether heparin prevents early brain injury (EBI) after subarachnoid hemorrhage (SAH) in mice. SAH was induced by endovascular perforation in mice randomly assigned to sham-operated (n = 8), SAH + vehicle (n = 12), SAH + 10 U heparin pretreatment (n = 11), and SAH + 30 U heparin pretreatment (n = 14) groups. At 24 h post-SAH, severity of SAH, neurological scores, and brain water content were evaluated. Low-dose heparin pretreatment improved neurobehavioral function, and decreased brain edema in the ipsilateral cerebral hemisphere to the perforation side. High-dose heparin had a tendency for increased SAH, which obscured the neuroprotective effects by heparin. Low-dose heparin pretreatment may decrease the development of post-SAH EBI.