| Project/Area Number |
05670078
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Environmental physiology (including Physical medicine and Nutritional physiology)
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| Research Institution | NARA Women's University |
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Principal Investigator |
MIKI Kenju Life Science and Human Technology, Department of Environmental Health, Associate Professor, 生活環境学部, 助教授 (80165985)
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| Project Period (FY) |
1993 – 1994
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| Project Status |
Completed (Fiscal Year 1994)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1994: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1993: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Keywords | exercise / arterial pressure / energy metabolism / sympathetic nerve activity / conscious rat / 腎交感神経活動 |
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| Research Abstract |
The purpose of the present study is to determine the effects of mild exercise (treadmill, 20m/min over 30 min) on the regulatory system of the arterial pressure and the relative utilization of lipid and carbohydrate for energy metabolism with special references to the sympathetic nervous system in conscious rat.
Wister rats weighing 290<plus-minus>29g (SE,n=10) were instrumented chronically with a stainless steel electrode for the measurement of renal sympathetic nerve activity (RSNA) and catheters for the measurements of arterial (Pa) and venous pressure (Pcv) through the femoral artery and vein under anesthesia with pentobarbital sodium (50mg/kg ip.). At least 2 days after the recovery period of sugary, rats ware placed on the treadmill. The experimental procedure is consisted of, 1) 60min resting of home cage, 2) 60 min of resting on the treadmill lane, 3) Exercise (20m/min over 30min), 4) 60 min of recovery on the treadmill lane, 5) 60min of recovery of home cag
Systemic arterial pressure increased due to exercise, but it decreased in temporal fashion by 8<plus-minus>2mmHg after the exercise relative to the pre-exercise level. Respiratory quotient decreased in sustained manner after exercise from 0.82<plus-minus>0.02 of the pre-exercise level to 0.72<plus-minus>0.01 of 16-60 min after end of exercise. RSNA also decreased after end of the exercise from 30<plus-m
These data suggest that dynamic exercise induces sustained suppression of the sympathetic nerve activity after end of the exercise in rats. This decreases in sympathetic nerve activity might decrease in total peripheral resistance or cardiac output such that systemic arterial pressure decreased. The sustained reduction of sympathetic nerve activity may be involved in regulating relative utilization of lipid and carbohydrate for energy production after exercise. The mechanisms underlying the sustained decreases in sympathetic nerve activity should be studied in further experiments.
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