Abstract
The authors evaluated the pathological feature of atheromatous plaques of rabbit model in relation to spectral properties of laser-excited fluorescence of doxycycline (Dc: tetracycline derivatives) that has selectively accumulated to the plaques.
We administrated Dc intravenously to the rabbit models and detected the spectra of their resected aorta. Excitation source used id third-harmonic beam (355 nm) of Nd:YAG laser, whose immediated power and beam diameter are approximately 10μW and 100μm respectively. We employed Hematoxylin-Eosin and Elastica-Masson stains for each 5μm section along the spotts after spectral detection.
The result shows that the intensity ratio of atheromatous plaques, that calculated as a ratio of the photon count at proper fluorescence of Dc to that at auto-fluorescence of arterial wall, have pathologically a good relation to the extent of their atherosclerotic change. The intensity ratio mainly reflected the lipid deposits that found superficially in the plaques, and approximately fibrous changes contributed to reducing the ratio. On the other side, it is thought that the lipid deposits found deeply in the plaques were related with the high value persistence of intensity ratio, especially in the plaques with severe atherosclerotic changes.
We thought Dc is one of hopeful drugs that may give us a new diagnostic parameter of atherosclerosis.
