| Project/Area Number |
17500439
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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 |
Sports science
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| Research Institution | Nara Medical University |
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Principal Investigator |
ISHIZASHI Hiromichi Nara Medical University, School of Medicine, Associate Professor, 医学部, 講師 (50260807)
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| Co-Investigator(Kenkyū-buntansha) |
FUJIMURA Yoshihiro Nara Medical University, School of Medicine, Professor, 医学部, 教授 (80118033)
MATSUMOTO Masanori Nara Medical University, School of Medicine, Assistant Professor, 医学部, 講師 (60316081)
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| Project Period (FY) |
2005 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 2006: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2005: ¥1,100,000 (Direct Cost: ¥1,100,000)
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| Keywords | VWF / ADAMTS13 / sweating / dehydration / HCT / Exercise / 夏季 / 循環血漿量 |
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| Research Abstract |
von Willebrand factor (VWF) is synthesized in vascular endothelial cells and released into the plasma as "unusually large" VWF multimers (UL-VWFM), which are degraded byADAMTS13. Deficiency of ADAMTS13 increases the plasma levels of UL-VWFM, which causes platelet clumping and finally leads to thrombus formation. Plasma VWF antigen (VWF : Ag) has been reported to increase during exercise, but the mechanism underlying this increase remains to be clarified. In this study, we have investigated the relationship between the severity of dehydration induced by sweating during exercise and the changes in plasma VWF levels after exercise. Plasma VWF : Ag was significantly higher immediately (116.6ア11%,) and 1 h after exercise (110.4±11 %) than the basal value before exercise (79.2±6 %). Ristocetin cofactor (Rcof) was also higher immediately (133.3±9 %) and 1 h (126.9±10 %) after exercise than the basal value (87.4±6 %). Plasma ADAMTS13 activity was unchanged immediately after exercise (77.2±4%) compared to the basal value, but significantly decreased 2 h after exercise (67.2±3%). These findings indicate that the imbalance between the early increase in VWF : Ag after exercise and the subsequent decrease in ADAMTS13 activity may reflect a predisposing state for the development of cardiovascular events, but conversely the decrease in ADAMTS13 activity may play an important role in degrading large amounts of VWF produced and preventing the occurrence of cardiovascular events early after exercise. In addition, no significant correlation was found between various parameters including dehydration rate, heart rate, and maximal oxygen uptake to VWF : and ADAMTS13 activity immediately and 1 h after exercise. However, VWF : Ag after exercise tended to be positively correlated with the dehydration rate during exercise (p<0.01, r=0.74), suggesting that severe dehydration might be related to the tendency toward thrombus formation.
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