| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1995: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1994: ¥1,700,000 (Direct Cost: ¥1,700,000)
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| Research Abstract |
We examined the acute effects of aerobic exercise upon cardiac sympatho-vagal activities, beta-endorphin, atrial and brain natriuretic peptides (ANP and BNP), and EEG changes associated with postexercise hypotension. Eight adult male subjects volunteered for this study and visited laboratory on separate days for resting control (C,30-min quiet resting) and exercise (EX,30-min ride on a cycle ergometer, 50% of heart rate range) at random. Measurements were consisted of beat-by-beat systolic and diastolic blood pressures (SBP and DBP), cardiac sympatho-vagal activities (ECG R-R interval power spectral analysis : sympathetic activity index, SNS,and para-sympathetic activity index, PNS) and EEG frequency power spectral analyzes. In addition, plasma beta-endorphin, ANP,BNP,catecholamine, aldosterone and renin activity were measured immediately before, during and 30-min after the experimental treatments. Results indicated that none of these measurements showed any significant changes during C condition. There were however significant decreases in SBP and DBP after EX (p<0.05). These changes were accompanied by significant increases in ANP and BNP observed during EX and significant postexercise increases in para-sympathetic activity (*PNS index), EEG alpha wave component and beta-endorphin together with significant decreases in SNS index and delta wave component (p<0.05). Changes in alpha wave component were significantly correlated (r=0.56, p<0.05) with relative changes in beta-endorphin. These data suggest that a moderate exercise could bring about postexercise hypotension by modulating natriuretic peptides and beta-endorphin levels with subsequent changes in autonomic nervous system activities.
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