norepinephrine ( 10 ( -4 ) m ) decreased pial arteriolar diameters similarly in all three groups ( 27 % , 28 % , and 21 % , respectively ) , but only the sham-operated group exhibited pial arteriolar dilation in response to hypotension ( 28 % at 33 mm hg ) .
C0028351
norepinephrine
C0020649
hypotension