2003 Fiscal Year Final Research Report Summary
Vital Observation of Hypoxic Vasoconstriction at the Pulmonary Microvessel with a Soft X-ray System
| Project/Area Number |
14571275
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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 |
Thoracic surgery
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| Research Institution | School of Health Science, International University of Health and Welfare |
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Principal Investigator |
MURAYAMA Fumio International University of Health and Welfare, School of Health Science, Professor, 保健学部, 教授 (60200309)
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| Co-Investigator(Kenkyū-buntansha) |
SOHARA Yasunori Jichi Medical School, Department of Surgery, Professor, 教授 (60114097)
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| Project Period (FY) |
2002 – 2003
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| Keywords | Pulmonary Microcirculation / Vital Observation / Soft X-ray Inverter System / hypoxic Vasoconstriction |
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| Research Abstract |
Although many investigators have, been reported the mechanism of hypoxic pulmonary hypertension, it is not yet clearly shown which level of pulmonary microvessels are refer to rise a resistance. We also have been studying pulmonary hypoxic disorders by using Sohara's vital observation system for less than 200 p in pulmonary microvessels, but we did not find the hypoxic vasoconstriction at the less than 200 p m microvessels. Thus, we developed a technique for vital observation of the pulmonary microvessels (200μm -600μm) in rats that is based on soft x-ray inverter system in order to visualize the hypoxic vasoconstriction.
Materials and Methods
Male Donryu rats were anesthetized with pentobarbital sodium and diazepam. After mechanical ventilation was established, the left chest wall was resected and the left lung was placed into the special hand-made chamber on soft X-ray inverter system. Radiopaque contrast medium was injected and pulmonary microangiogram was recorded. Animals were ventilated with room air and then 15%O2 in N2 gas, and the changes in diameter of the small pulmonary arteries were determined. The soft X-ray inverter system ; focal spot : 0.1mm, power : 10-60kV and 0.1-0.8mA. The image processing system ; MT-PCI-CD, NVS. The image-analysis software ; Image-Pro plus NVS.
Results and Discussion
Hypoxic ventilation (15%O2 in N2) decreased PaO2 from 80 mmHg to 45 mmHg and increased mean pulmonary arterial pressure from 20 mmHg to 25mmHg. Hypoxic ventilation decreased the diameter of small arteries from 252μ m to 234μm, from 3 in to 305μm, and from 400μm to 394μm.
We were able to confirm the hypoxic vasoconstriction at the level of 250-350μm visually with the soft X-ray inverter system.
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Research Products
(2 results)
