Premium
Change in chemical composition of lipids accumulated in atheromas of rabbits following photodynamic therapy
Author(s) -
Hayashi Junichi,
Saito Takashi,
Aizawa Katsuo
Publication year - 1997
Publication title -
lasers in surgery and medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 112
eISSN - 1096-9101
pISSN - 0196-8092
DOI - 10.1002/(sici)1096-9101(1997)21:3<287::aid-lsm9>3.0.co;2-m
Subject(s) - atheroma , chemistry , cholesterol , fourier transform infrared spectroscopy , photodynamic therapy , chlorin , porphyrin , concomitant , medicine , biochemistry , physics , organic chemistry , quantum mechanics
Background and Objective Mono‐L‐aspartyl chlorin e6 (NPe6) has been used in the photodynamic therapy of neoplasms. This substance has been shown to accumulate in atheroma of rabbits. We evaluated the change in the lipid components of atheromas after photodynamic therapy with NPe6 using Fourier transform infrared (FTIR) microspectroscopy. Study Design/Materials and Methods Rabbits were fed a cholesterol‐rich diet for 20 weeks. Six hours after they were administered NPe6 (2mg/kg), the atheroma present on the abdominal aorta was irradiated with a diode laser with 100J/cm 2 or 200J/cm 2 of the tissue fluence. Tissue samples were prepared for FTIR and histological analysis. Results Specimens of atheroma from the untreated animals appeared as fatty streaks whose infrared spectra exhibited characteristic peaks at 1,738 −1 cm −1 , 1,468 cm −1 , 1,380 cm −1 , and 1,174 cm −1 , indicating the accumulation of cholesterol ester. Seven days after photodynamic therapy, FTIR microspectroscopic analysis showed a marked decrease in the peak intensity in the treated atheroma related to the =C=O ester bond at 1738 cm −1 with no concomitant increase in the intensity of the peaks related to free cholesterol. Conclusion Findings suggest a dissociation of ester bonds and the depletion of cholesterol esters in the atheromas after photodynamic therapy with NPe6. The lipids accumulated in the atheroma were perhaps decreased or destroyed following such treatment. Lasers Surg. Med. 21:287–293, 1997. © 1997 Wiley‐Liss, Inc.