plasma concentrations of gh were reduced by the peripheral administration of ne , which might be expected not to cross the blood-brain-barrier ( bbb ) , alpha 1/alpha 2 agonists clonidine and p-amino clonidine ( which does not cross bbb ) , ne/e precursors l-dopa and dops , and the beta agonist , isoproterenol .
C0028351
ne
C0000378
dops