Characterizing photothrombotic distal middle cerebral artery occlusion and YAG laser-induced reperfusion model in the Izumo strain of spontaneously hypertensive rats.

摘要

No study has systematically studied the relevance of original Izumo strain of spontaneously hypertensive rats (SHR/Izm) as a stroke model. Furthermore, both SHR/Izm and stroke-prone SHR/Izm (SHRSP/Izm) are commercially available, and recent progress in genetic studies allowed us to use several congenic strains of rats constructed with SHR/Izm and SHRSP/Izm as the genetic background strains. A total of 166 male SHR/Izm and 17 male SHRSP/Izm were subjected to photothrombotic middle cerebral artery (MCA) occlusion with or without YAG laser-induced reperfusion. The pattern of distal MCA was recorded. Infarct volumes were determined with 2,3,5-triphenyltetrazolium chloride. At 24 or 48 h after MCA occlusion, infarct volumes in the permanent occlusion and 2-h occlusion groups (88 +/- 22 [SD] and 87 +/- 25 mm(3), respectively) were significantly larger than that in the 1-h occlusion group (45 +/- 14 mm(3)), indicating the presence of sizeable zone of penumbra. Infarct size in SHRSP/Izm determined at 24 h after MCA occlusion was fairly large (124.0 +/- 34.8 mm(3), n = 10). Infarct volume in SHR/Izm with simple distal MCA was 76 +/- 19 mm(3), which was significantly smaller than 95 +/- 22 mm(3) in the other SHR/Izm with more branching MCA. These data suggest that this stroke model in SHR/Izm is useful in the preclinical testing of stroke therapies and elucidating the pathophysiology of cerebral ischemia/reperfusion.