the sympathoadrenal activity during acute ( from 0.5 to 10 h ) and prolonged ( 4 days ) head-down bed rest was assessed in eight healthy men ( 24 +/- 1 yr ) by measuring epinephrine ( e ) , norepinephrine ( ne ) , dopamine ( da ) , and methoxylated metabolite levels in their plasma and urine .
C0014563
epinephrine
C0028351
norepinephrine