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  • H I Chen
  • 1991
The effects of 30-h sleep deprivation on cardiorespiratory function either at rest or in exercise were studied in 15 young healthy male volunteers. All subjects performed 1-min incremental exercise tests on a bicycle ergometer until exhaustion and endurance exercise tests at 3/4 of their maximal work rates. Arterialized venous blood samples were withdrawn(More)
BACKGROUND Platelets play an important role in the pathogenesis of cardiovascular diseases. It is also noticed that on one hand, regular exercise can reduce the risk of cardiovascular diseases, and on the other hand, vigorous exercise provokes sudden cardiac death. We therefore hypothesize that various intensities of exercise may affect platelet function(More)
The central cardiovagal mechanism of the medulla oblongata was explored by stimulation and ablation techniques in the anesthetized cat. Insertion of an electrode into the nucleus solitarius (NS) occassionally evoked slight and transient bradycardia, but similar mechanical irritation to the nucleus ambiguus (NA) usually evoked prolonged and intense(More)
To determine whether sleep is necessary for the peripheral sympathetic nervous system response to exercise, we compared eight subjects' sympathoadrenal responses to treadmill walking at a constant exercise rate eliciting a heart rate around 160 beats X min-1 after normal sleep with those measured after a 50-h sleepless period. We found that sleeplessness(More)
To study the effects of flow on in situ endothelial intracellular calcium concentration ([Ca(2+)](i)) signaling, rat aortic rings were loaded with fura 2, mounted on a tissue flow chamber, and divided into control and flow-pretreated groups. The latter was perfused with buffer at a shear stress of 50 dyns/cm(2) for 1 h. Endothelial [Ca(2+)](i) responses to(More)
This study was conducted to investigate the effects of chronic exercise on adrenergic agonist-induced vascular responses in spontaneously hypertensive rats (SHR). Four-week-old male SHR and Wistar-Kyoto rats were divided into control and trained groups. The trained groups ran on a drum exerciser at 70% of peak oxygen consumption for 60 min/day 5 days/wk for(More)
BACKGROUND Physical activity can reduce sympathetic tone and may be beneficial to human health. Whether the vascular responses to norepinephrine (NE), an adrenergic vasoconstrictor, could be altered by chronic exercise was unclear. We therefore conducted this study to investigate the effects of endurance exercise training on NE-induced vasoconstrictive(More)