Abstract
We investigated the efficacy of drugs used to treat brain edema in a rat acute cerebral infarction model by MRI image analysis. Twenty-six Sprague-Dawley rats were anesthetized with halothane, and the right middle cerebral artery was permanently occluded via a transvascular approach using a nylon 2-0 suture. At 24 hours after the occlusion, axial T2-weighted MRI images were taken before and 2 hours after intraperitoneal administration of a test drug. After the administration of 1.7 g/kg glycerol (n=9), 3.3 g/ kg mannitol (n=9) or 17 mg/kg furosemide (n=8), the high intensity area (HIA) in the whole brain amounted to 92% (p<0.01), 94% (p=0.07), or 95% (p=0.03), respectively as compared to the corresponding HIA before administration. The HIA in the cerebral cortex amounted to 87% (p<0.01), 89% (p=0.03), or 98% (p=0.47), and that in the striatum to 102%, 106%, or 87% (p<0.05), respectively. The signal intensity change (before →aftre) was 54→49 (p<0.01), 54→50 (p<0.01), or 55→54 in the left side normal cortex; 102→97 (p<0.01), 100→98, or 98→97 in the injured side cortex; and 100→93 (p<0.01), 94→88 (p=0.03), or 94→94 in the injured side striatum, respectively. Improvement of edema by the drugs was observed as a reduction in HIA and a decrease in signal intensity on MRI, and the changes were significant in the case of administration of each of glycerol, mannitol and furosemide.
