| Project/Area Number |
06558125
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| Research Category |
Grant-in-Aid for Developmental Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Biomedical engineering/Biological material science
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| Research Institution | The University of Tokushima |
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Principal Investigator |
ARAKI Tsutomu Univ.Tokushima, Engineering, Prof., 工学部, 教授 (50136214)
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| Co-Investigator(Kenkyū-buntansha) |
TOHNO Yoshiyuki Nara Medical University, Anatomy, Assist, Prof., 医学部, 助教授 (40075023)
MISAWA Hiroaki Univ.Tokushima, Engineering, Prof., 工学部, 教授 (30253230)
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥5,900,000 (Direct Cost: ¥5,900,000)
Fiscal Year 1995: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1994: ¥5,000,000 (Direct Cost: ¥5,000,000)
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| Keywords | HUMAN ARTERY / FLUORESCENCE / TIME-RESOLVED FLUOROMETER / AGING / 老化 / 動脈硬化 / ナノ秒蛍光 / 加齡 |
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| Research Abstract |
There are many reports that describe laser excited autofluorescence spectroscopy of human arteries. However, spectroscopic data are limited, since resultant signals are only light intensity and emission spectral profile. Here we applied the nanosecond fluorometry to detect aging in human artery. As the examination, two arteries from cadavers were subjected : (1) aorta and (2) basilar artery. The age dependent heterogeneity of the fluorescence decay curve was examined. The fluorescence had emission maximum at 450 nm. The decay time of the temporal fluorescence was in nanosecond scale when excited with a pulsed light. The fluorescence decay time of basilar artery showed the age-dependency, except for one case. However, aorta did not show the age dependency. We assume that aging of aortic wall is accelerated by mechanical stress due to pulsation of the high blood pressure, resulting in indistinguishable decay curves. On the other hand, the mechanical stress inside cerebral artery is not strong and does not influence the tissue aging. Resultant fluorescence decay curve thus reflects the actual age. The fluorescence decay of the 45 years basilar artery was extraordinarily faster than that of 92 years. From the examination of Ca content, we found the 45 years basilar artery contained a large amount of calcium. Because calcium content in the tissue is one indicator of aging, such the fast fluorescence decay of the 45 years artery is reasonably explained : the physiological age of the 45 years artery was older than 90 years.
Our result is the first report that the fluorescence decay curve of artery changes with respect to the age. However, it is still ambiguous what substance fluoresces in the arterial wall and why fluorescence decay time decreases with age. The cause of death may strongly relate to the fluorescence. It is necessary to clarify these for further application of the arterial autofluorescence to the study of tissue aging.
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