Photochemical Thrombosis of Middle Cerebral Artery in Rats: A Modified Model

Objective To improve the photochemical thrombosis model of middle cerebral artery (MCA) in rats, to make the model more suitable for the research of acute cerebral infarction.Materials and Methods Hematoporphyrin derivative (HPD), a photosensitizing dye, was injected into male Wistar rat via the femoral vein (12.5mg/kg), while He-Ne laser with 630 nm wavelength was focused on the proximal segment of MCA for 15 minutes. When white thrombus was seen under an operation microscope, bilateral common carotid artery (CCA) were occluded with an artery clip for 60 minutes, then removed the clip. The features of the thrombus were observed under both light and electronic microscope. The MRI manifestation of the infarcted area was also observed.Results The occlusive platelet thrombus could be seen in the projected segment of MCA. The infarcted lesion in MCA area was large and stable.Conclusion Using modified procedure, the preparation of photochemical MCA thrombosis model in rats needs only 60 minutes to occlude bilateral CCA, thus, the thrombolytic agents can reach the thrombus via the similar route as used in clinical practice. This procedure is rather economic and can produce large and stable infarcted area, thus, it is very suitable for the thrombolytic research in acute cerebral infarction.