A photosensitizer, mono-L-aspartyl chlorin e6: NPe6, was administered intravenously into the ear vein of cholesterol-fed atherosclerotic rabbits at a dose of 5mg/kg of body weight. At 6 hours after NPe6 administration, the atherosclerotic lesions of the carotid artery were irradiated by a diode laser at 664 nm of wavelength with 200J /cm2. The carotid artery irradiated by laser beam were digested with NaOH, excised for histological analysis using, the scanning electron microscopy.
There are number of methods of removing all nonelastin tissues from the carotid artery from which we have chosen the hot alkaline method originally proposed by Lowry et al. This method is desined for preserving the natural organization of elastin components in the digested carotid. The architecture of the elastic fiber networks in the atherosclerotic plaque irraiated by a diode laser were destroyed and the clumps of debris were occasionally observed. These findings suggested that the architecture of the elastic fiber network in the atherosclerotic plaque were destroyed by photodynamic therapy.
