the aim of this study was to determine the effects of a 5-h weightlessness simulation ( using supine bed rest or head-down tilt at -10 degrees = hdt ) on plasma renin activity ( pra ) , aldosterone ( pa ) , and catecholamines ( epinephrine-e , norepinephrine-ne , and dopamine-da ) and to compare the results with those obtained with horizontal bed rest ( br ) , which is often taken as a control situation for simulation studies .
C0014563
epinephrine
C0028351
norepinephrine