2000 Fiscal Year Final Research Report Summary
DEVELOPMENT OF INTRAVITAL LASER MICROSCOPE FOR VISUALIZATION OF MICROVASCULAR PO_2 DISTRIBUTION
| Project/Area Number |
11558103
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| Research Category |
Grant-in-Aid for Scientific Research (B).
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
Biomedical engineering/Biological material science
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| Research Institution | UNIVERSITY OF TOKYO |
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Principal Investigator |
SHIBATA Masahiro UNIV OF TOKYO, GRAD SCH OF MED, ASSI PROF, 大学院・医学系研究科, 講師 (60158954)
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| Co-Investigator(Kenkyū-buntansha) |
ANDO Joji UNIV OF TOKYO, GRAD SCH OF MED, PROF, 大学院・医学系研究科, 教授 (20159528)
YAMAGATA Mikio NIKON ENGINEERING CO, MANAGER, 光学部, 課長(研究職)
KAMIYA Akira NIHON UNIV, GLOBAL BUSINESS SCH, PROF, グローバルビジネス研究科, 教授 (50014072)
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| Project Period (FY) |
1999 – 2000
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| Keywords | OXYGEN TENSION / PHOSPHORESCENCE LIFETIME / Pd-PORPHYRIN / SKELETAL MUSCLE / ARTERIOLES / LASER / VITAL MICROSCOPY |
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| Research Abstract |
To clarify the oxygen transport across the microvessed and oxygen distribution in the skeletal muscle, we have newly designed an intravital laser microscope with oxygen-dependent quenching of phosphorescence technique. Pd-porphyrin solution was injected into the systemic blood, and its phosphorescence excited by N_2/dye pulse laser in the tissue area of 15 μm in diameter was captured by a photomultiplier. In vitro and in vivo oxygen tension (pO_2) measurements revealed the efficiency of this method because of its non-invasiveness, accuracy, and rapid response time. This technique was applied to pO_2 measurements in the rat cremaster muscle microcirculation. The arteriolar and venular pO_2 measurements were performed at the several regions classified by branching order. The mean arteriolar pO_2 of different orders decreased according to increase the branching (A1 : 72.4, A2 : 51.8 and A3 : 44.1 mmHg), however venular pO_2 were independent on vessel orders (V1 : 27.5, V2 : 28.6 and V3 : 32.0 mmHg). Interstitial pO_2 adjacent to arterioles of different orders were significantly lower than those of intravascular pO2 (I1 : 47.8, I2 : 35.8 and I3 : 24.4 mmHg). In conclusion, the present study has shown that the phosphorescence quenching laser microscope can be used to clarify the transport of O_2 across microvessels and the distribution of O_2 in tissues, although more regional data on pO_2 values in tissues are required in the current. The use of lasers to excite phosphorescent probes enables a smaller area of tissue to be illuminated (<10μm), if the potential for tissue damage is clarified in detail. In addition, we found a large reduction in pO_2 levels of different order arterioles as well as a large pO_2 gradient at the interface between blood and tissue. These findings suggest that capillaries are not the sole source of oxygen supply to surrounding tissue.
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Research Products
(12 results)
