Cardiovascular mechanisms are maintained by intermittent artificial gravity exposure during bed rest deconditioning
نویسندگان
چکیده
منابع مشابه
Supine cycling plus volume loading prevent cardiovascular deconditioning during bed rest.
There are two possible mechanisms contributing to the excessive fall of stroke volume (and its contribution to orthostatic intolerance) in the upright position after bed rest or spaceflight: reduced cardiac filling due to hypovolemia and/or a less distensible heart due to cardiac atrophy. We hypothesized that preservation of cardiac mechanical function by exercise training, plus normalization o...
متن کاملDeterioration of left ventricular chamber performance after bed rest : "cardiovascular deconditioning" or hypovolemia?
BACKGROUND Orthostatic intolerance after bed rest is characterized by hypovolemia and an excessive reduction in stroke volume (SV) in the upright position. We studied whether the reduction in SV is due to a specific adaptation of the heart to head-down tilt bed rest (HDTBR) or acute hypovolemia alone. METHODS AND RESULTS We constructed left ventricular (LV) pressure-volume curves from pulmona...
متن کاملEffects of artificial gravity during bed rest on bone metabolism in humans.
We report results from a study designed to explore the utility of artificial gravity (AG) as a countermeasure to bone loss induced by microgravity simulation. After baseline testing, 15 male subjects underwent 21 days of 6 degrees head-down bed rest to simulate the deconditioning associated with spaceflight. Eight of the subjects underwent 1 h of centrifugation (AG; 1 G(z) at the heart, 2.5 G(z...
متن کاملRegulation of muscle sympathetic nerve activity after bed rest deconditioning.
Cardiovascular deconditioning reduces orthostatic tolerance. To determine whether changes in autonomic function might produce this effect, we developed stimulus-response curves relating limb vascular resistance, muscle sympathetic nerve activity (MSNA), and pulmonary capillary wedge pressure (PCWP) with seven subjects before and after 18 days of -6 degrees head-down bed rest. Both lower body ne...
متن کاملTranscutaneous electrical acupuncture stimulation as a countermeasure against cardiovascular deconditioning during 4 days of head-down bed rest in humans
OBJECTIVE Spaceflight is associated with cardiovascular deregulation. However, the influence of microgravity on the cardiovascular system and its mechanisms and countermeasures remain unknown. Our previous studies have demonstrated that transcutaneous electrical acupuncture stimulation (TEAS) is effective in improving orthostatic tolerance (OT). The purpose of this study was to determine if TEA...
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ژورنال
عنوان ژورنال: The FASEB Journal
سال: 2008
ISSN: 0892-6638,1530-6860
DOI: 10.1096/fasebj.22.1_supplement.752.9