Abstract
As a part of our research on the application of pheophorbide-a using photodynamic therapy (PDT), we assessed the accumulation of this agent in arteriosclerotic lesions and analyzed its fluorescence spectrum. After inducing arteriosclerosis in the abdominal aortae of Japanese white rabbits, we administered them pheophorbide-a (20 mg/kg) via the jugular vein and sacrificed them for autopsy after 1, 6, 24, and 48 hours later. Red fluorescence of pheophorbide-a was obsereved in the thickened intima by fluorescence microscopy, and spectral analysis revealed a fluorescence spectrum peak at 680nm. This fluorescence intensity peak at 6 hours after administration tend to diminish. Pheophorbide-a shows accumulation in thickened intima, and it appears that diagnosis of the atherosclerosis using pheophorbide-a by fluorescence spectrum analysis will be able to apply this agent for PDT in the future.
