The New diagnostic and therapeutic method for athcrosclerotic lesious by coufocal laser scauning microscopy

1994 Fiscal Year Final Research Report Summary

• Project/Area Number: 05507003
• Research Category: Grant-in-Aid for Developmental Scientific Research (A)
• Allocation Type: Single-year Grants
• Research Field: General surgery
• Research Institution: Tohoku University
• Principal Investigator: MORI Shozo Tohoku University Medicine (2 surgery) Professor, 医学部, 教授 (70004877)
• Co-Investigator(Kenkyū-buntansha): SATO Shunichi Tohoku University Medicine (2 surgery) Associate Professor, 素材工学研究所, 助教授 (30162431) ; KUROKAWA Yoshimochi Tohoku University Medicine (2 surgery) Research Associat, 医学部・附属病院, 助手 (80215087) ; KATAYAMA Masafumi Tohoku University Medicine (2 surgery) Research Associate, 医学部・附属病院, 助手 (00177411) ; SATOMI Susumu Tohoku University Medicine (2 surgery) Lecturer, 医学部, 講師 (00154120) ; OHKUMA Tsuneo Tohoku University Medicine (2 surgery) Lecturer, 医学部・附属病院, 講師 (50160453)
• Project Period (FY): 1993 – 1994
• Keywords: atherosclerosis / photodynamic therapy / laser / doxycycline

Research Abstract

We report the study on basic featurers of tetracyline series antibiotics for photosensitive substances. Deoxycycline (DOXY), NPRMTC,PRMYC,MINO and OCT were potent in order of absorption spectrum and absorbance at 355nm (third harmonic beam of Nd : YAG laser). The feature of each drug for absorption and wash out on domestic rabbit arteriosclerosis site was studied with these antibiotics for intravenous injection. When lesinal site vessel was observed with time, with antibiotics, the fluorescent intensity ratio to normal site vessel was significantry high. DOXY was shown the highest intensity of fluoresence, in change with time among each type of drug. On the basis of our experience thus far, the present experiment was performed.
DOXY (35mg/kg) was administered to arteriosclerosis rabbits. Their aortae were dissected. Five hours after adoministration, Nd : YAG laser (355nm) was applied in the output 24J/cm2. The sites where photodynamic therapy (PDT) was applied were observed 0.5,1,3,7 and 42 days later. In PDT group, the hypertrophic intimae consisting of mast cells showed the cellular changes 0.5 day later. The inbalanced intracellular concentration and constricted cells were recognized on the first day. The cells which lost their nuclei started to melt and left only fibrous compnents around them on the third day. Past of the lesions showed morphological changes including the increased density and atrophy on the 7th day. On the 42nd day, although the fibrous components and atrophy were still observed on the hyoertrophic intimae, the lesions were reduced.