to study possible modifications of norepinephrine and epinephrine kinetics ( metabolic clearance rate and half-times ) by inhibition of binding to alpha- and/or beta-adrenergic receptors , norepinephrine and epinephrine were iv infused in the absence or presence of the alpha-adrenergic blocking agent phentolamine , the beta-adrenergic blocking agent propranolol , and during the combined administration of phentolamine and propranolol .
C0028351
norepinephrine
C0014563
epinephrine