LASER-INDUCED FLUORESCENCE .3. QUANTITATIVE-ANALYSIS OF ATHEROSCLEROTIC PLAQUE CONTENT

Background and Objective: Laser-induced fluorescence (LF) spectroscopi c analysis of the chemical composition of atherosclerotic plaque was e xamined. Study Design/Materials and Methods: The intima of 18 dog aort as was injected with chemical compounds found in atherosclerotic plaqu e. Spectra were recorded in air prior to and after injection of collag ens I, III and IV, elastin, cholesterol, triglyceride, and beta-nicoti namide adenine dinucleotide (NADH). Results: Significant changes in LF intensity were detected after injection of collagens I and III, chole sterol and elastin in thoracic aorta (P < 0.001), but not with triglyc eride or NADH. Minor changes were detected in abdominal aorta. Multipl e regression analysis of LF intensity ratios demonstrated a clear corr elation with the quantity of injected collagens I (R(2) = 0.90-0.99) a nd III (R(2) 0.84-1.0), cholesterol (R(2) 0.72-0.76), and triglyceride (R(2) = 0.68-0.80) in both thoracic and abdominal aorta. The correlat ion between LF and atherosclerotic plaque composition was confirmed in a rooster model of atherosclerosis where multiple regression analysis predicted the measured aortic cholesterol (R(2) = 0.78) and triglycer ide content (R(2) = 0.96). Conclusions: (1) Fluorescence spectra recor ded from dog aorta were significantly altered by injection of collagen s I and III, cholesterol, and elastin. (2) LF may allow quantitative a ssessment of plaque chemical content. (C) 1995 Wiley-Liss, Inc.