Sympathoadrenal Activity and Cardiovascular Responses during Space Flight
Several ground-based simulation studies have been performed during which the gravitational stress has been reduced for shorter or longer periods of time. Simulated microgravity induces an increase in central venous pressure and a decrease in plasma norepinephrine (NE). In one experiment lasting 42 days of head-down tilted bed rest plasma NE did not change. These studies have therefore suggested that sympathoadrenal activity remains- unchanged or may even be reduced during a space mission. This hypothesis has, however, been refuted.1
KeywordsPlasma Volume Space Flight Muscle Sympathetic Nerve Activity Simulated Microgravity Lower Body Negative Pressure
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