Abstract: Abstract: Objective To explore the role of homocysteine（Hcy）on angiogenesis at peri infarct region after focal cere⁃ bral ischemia in rats, to elucidate inhibitory factors of angiogenesis, and to establish a clinic foundation for clinical brain functional recovery. Methods Spragur-Dawley (SD) male rats (n=36) were randomly divided into three groups with 12 rats in each group including Sham Operation (SO) group, Middle cerebral artery occlusion (MCAO) group and MCAO+Hcy group. The rats in Sham and MCAO groups were intra-peritoneally injected with 5 mL/(kg·d) saline and rats in MCAO + Hcy group were injected with 2% 5 mL/(kg·d) Hey solution from the same route. MCAO was introduced by intraluminal filament meth⁃ od after 7 d Hcy intervention. Rat brains were harvested on the 7th day after MCAO. BrdU（50 mg/kg, as a marker of cell pro⁃ liferation）was intraperitoneally injected three days before the rats were killed. High performance liquid chromatography （HPLC）was used to measure serum Hcy concentration in rats. Brain infarction size was observed by TTC staining. Immuno⁃ fluorescence staining was used to detect the number of BrdU+ /laminin+ cells at the thalamus of infarction side. Results Se⁃ rum Hcy concentration significantly higher in MCAO + Hcy group than in SO and MCAO groups（P < 0.05） . Brain damage increased and the number of BrdU+ /laminin+ cells decreased in MCAO + Hcy group compared with those of MCAO group （P < 0.05） . Conclusion Increased Hcy concentration in rats lead to more severe damage of cerebral infarction as well as to inhibit the angiogenesis at surrounding ischemia area.

Key words: brain infarction, disease models, animal, rats, Sprague-Dawley, homocysteine, angiogenesis