| Project/Area Number |
11671782
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Plastic surgery
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| Research Institution | The Univ.of Tokushima |
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Principal Investigator |
NAKANISHI Hideki The Univ.of Tokushima, Depart.of Plastic and Reconstr.Surg., Professor, 医学部・附属病院, 教授 (90164235)
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| Co-Investigator(Kenkyū-buntansha) |
HASHIMOTO Ichiro The Univ.of Tokushima, Depart.of Plastic and Reconstr.Surg., Research Associate, 医学部・附属病院, 助手 (70314870)
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| Project Period (FY) |
1999 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 2000: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1999: ¥2,700,000 (Direct Cost: ¥2,700,000)
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| Keywords | rabbit ear chamber / microcirculation of skin / thrombus formation / leukocyte / superoxide / hydroxyl radical |
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| Research Abstract |
We have studied about thrombus formation in the microcirculation of the skin. And we have found that the morphological composition of thrombi in the arterioles and venules was different.
A transparent round-table chamber (rabbit ear chamber : REC) was implanted in the earlobe of Japanese white rabbits. A complete microvascular network had formed in the chamber, and arterioles 20-30μm in diameter and venules 45-55μm in diameter were selected for experiments. Filtered light (400-500 nm light passed through a fluorescein isothiocyanate excitation filter from a high pressure mercury lamp) was irradiated onto the vessels through an objective lens. Thrombus in the microvessels was formed by the filtered light and solution of fluorescein sodium in the vessels. In the arterioles, the thrombi consisted of platelet aggregation, but in the venules, platelets and leukocytes accumulated on the endothelium.
We investigated the effects of the iron chelator desferrioxamine (DFX) on thrombus formation in the arterioles and venules of rabbit ear chamber. Occlusive thrombus formation time (o-time) was significantly extended by DFX both in the arterioles and the venules. This suggests that hydroxyl radicals may be important mediators in this model, as DFX is known as a hydroxyl radical scavenger.
On the study of the administration of the CD-18 and anti L-selectin antibody, the o-time was prolonged in the venules in which many leukocytes was observed on the thrombus formation.
We also assessed the endothelial dysfunction od microvessels by measuring viscosity of leukocytes in venules and the diameters of arterioles. In alloxan-induced diabetic rabbits, the adherent time of leukocytes to endothelium of venules was longer than in control rabbits. The results of the study of the administration of acetylcholine, L-arginine and sodium nitroprusside suggested the impairment of microvasculat relaxation in hyperglycemic rabbits.
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