2002 Fiscal Year Final Research Report Summary
Morphological changes and molecular mechanism in the carotid bodies after the termination of chronic hypoxia
| Project/Area Number |
13680048
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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 |
体育学
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| Research Institution | Kokushikan University |
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Principal Investigator |
KUSAKABE Tatsumi Ph.D. Kokushikan University Faculty of Physical Education, Professor, 体育学部, 教授 (80117663)
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| Co-Investigator(Kenkyū-buntansha) |
HAYASHIDA Yoshiaki MD, Ph.D. Univ. of Occup. & Envir. Health Dept. of Systems Physiol., Professor, 産業生態科学研究所, 教授 (40047204)
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| Project Period (FY) |
2001 – 2002
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| Keywords | Carotid body / Hypoxia / Termination of hypoxia / Morphometry / Vasodilation / Neuropeptide / Immunohistochemistry / Second messenger |
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| Research Abstract |
The carotid bodies after 2, 4, and 8 weeks of hypoxic exposure were enlarged by 1.2-1.5 times in the short axis, and 1.3-1.7 times in the long axis in comparison with the normoxic control ones. The enlarged carotid bodies contained a number of expanded vasculatures. Mean density of substance P (SP) and calcitonin gene-related peptide (CGRP) containing fibers was transiently high in the carotid bodies after 4 weeks hypoxic exposure, and decreased in those after 8-12 weeks exposure. Density of vasoactive intestinal polypeptide (VIP) fibers increased significantly in all periods of hypoxic exposure observed, and was especially high in those after 4 weeks exposure. Density of neuropeptide Y fibers was unchanged in the carotid bodies during hypoxic exposure. These characteristic changes suggest a possibility that the role of these neuropeptide containing fibers may be different in the carotid bodies after each of four periods of hypoxic exposure
In the carotid bodies after 8 weeks of hypoxic exposure, the percentage of small vessels with diameters less than 5 μm decreased to under 20%, that of diameters greater than 16 μm increased to over 20%. The carotid bodies 1 and 2 weeks after the termination of chronic hypoxia were diminished in size, although their short and long axes remained larger than the normoxic controls. Those 4 and 8 weeks after the termination of chronic hypoxia were diminished to nearly normoxic control level. In those 8 weeks after the termination of chronic hypoxia, about 45% of the blood vessels were small ones with diameters less than 5 μm and 10 μm. The percentage of relatively large vessels with diameters greater than 16 μm was less than 10%. In the carotid bodies 4 weeks after the termination of hypoxia, the density of NPY fibers increased
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Research Products
(16 results)
